UCSB  LIBRARY 


HUMAN   ANATOMY, 

GENERAL  AM)  SPECIAL. 
BY   ERASMUS   WILSON,  M.D., 

LECTURER   ON   ANATOMY,    LONDON. 

FOURTH  AMERICAN 
FROM   THE    LAST   LONDON    EDITION. 

EDITED   BT 

PAUL   B.  GODDARD,   A.M.,   M.D., 

PROFESSOR  OF  ANATOMY  AND  HISTOLOGY  IN  THE  FRANKLIN  MEDICAL  COLLEGE 
OF    PHILADELPHIA. 


"•"-BERT  Sc. 


WITH  TWO  HUNDRED  AND  FIFTY-ONE  ILLUSTRATIONS 
BY  GILBERT. 


PHILADELPHIA: 
BLANCHARD    AND    LEA. 

1855. 


Entered,  according  to  Act  of  Congress,  in  the  year  18*8,  oy 
LEA   AND   BLANCHARO, 

in  the  clerk's  office  of  the  District  Court  of  the  United  States  lor  tn» 
•  Eastern  District  of  Pennsylvania. 


Printed  by  T.  K  &  P.  O    Collins.  ' 


TO 


SIK  BENJAMIN  COLLINS  BRODIE,  BART.,  F.R.S. 

SERGEANT-SURGEON   TO    THE   QUEEN, 
MEMBER    OF    THE    INSTITUTE    OF    FRANCE, 


IN  ADMIRATION   OF    THE   HIGH  ATTAINMENTS 


WHICH  HAVE  JUSTLY  PLACED  HIM 


IN     THE     FIRST     RANK     OF     HIS     PROFESSION, 


IS     RESPECTFULLY     INSCRIBED 


THE   AUTHOR. 


PREFACE. 


THE  Preface  to  this  little  volume  may  be  "written  in  a  few  words.  It 
first  saw  the  light  in  the  spring  of  1840,  and  now,  in  the  autumn  of  1844, 
has  reached  its  Third  Edition.  In  this  short  period,  less  than  five  years, 
five  thousand  copies  have  been  distributed  among  the  Members  of  the 
Profession,  many  also  taking  their  place  in  the  libraries  of  Gentlemen, 
who,  although  not  of  the  Profession,  justly  consider  that  some  genera) 
knowledge  of  the  structure  of  the  body  is  an  essential  part  of  a  liberal 
education.  In  the  same  period,  a  second  edition  of  the  work  has  appeared 
in  America ;  and  a  translation,  from  the  pen  of  Dr.  Hollstein,  has  been 
completed  in  Berlin. 

Thus  the  volume  has  quickly  returned  for  review  to  the  hands  of  the 
Author ;  and  he  trusts  that  an  examination  of  the  second  and  present  edi- 
tions will  prove  that  he  has  not  neglected  this  advantage.  He  has  care- 
fully corrected  such  oversights  and  omissions  as  may  have  occurred  in 
the  completion  of  a  work  on  so  extensive  a  subject;  many  parts  which 
seemed  scantily  treated,  he  has  entirely  re- written;  and  he  has  endea- 
voured to  give  as  full  a  description  of  every  point  in  Anatomy,  whether 
important  or  trivial,  as  is  consistent  with  the  limits  and  objects  of  a  Prac- 
tical Manual. 

Two  features  in  the  Anatomist's  Vade  Mecum  appear  to  the  Author  to 
deserve  notice: — the  first  relates  to  the  labours  of  his  professional  bre- 
thren ;  the  second  to  the  illustrations  contained  in  the  work.  On  the  first 
of  these  heads  the  Author  begs  to  remark,  that  he  considers  it  a  duty,  as 
well  to  them  as  to  his  readers  and  himself,  to  quote  all  recent  observations 
arid  discoveries  in  Anatomy  which  may  have  interest,  and  to  give  as 
complete  an  abstract  of  such  discoveries  as  the  scheme  of  the  work  will 
permit.  By  pursuing  this  plan,  the  Author  trusts  to  distinguish  his 
volume  as  the  Record  of  the  Profession  at  large,  and  not  as  the  text-book 
merely  of  a  particular  school.  And,  in  furtherance  of  his  object,  he  has 

(vh) 


Vlll  PREFACE. 

to  request  a  continuance  of  those  communications  from  scientific  investi- 
gators, which  have  hitherto  so  materially  aided  him. 

The  woodcut  illustrations  which  accompany  the  Anatomist's  Vade 
Mecum  have  been  increased  with  each  edition.  Several  of  the  new 
figures  are  illustrative  of  General  Anatomy,  and,  to  insure  their  absolute 
correctness,  have  been  drawn  from  the  microscope  by  the  Author  himself, 
with  the  aid  of  the  camera  lucida.  Figures  13,  14,  15,  showing  the 
changes  which  occur  during  the  development  of  bone ;  figures  63-66,  the 
minute  anatomy  of  cartilage ;  and  figure  103,  the  structure  of  the  ultimate 
muscular  fibril,  are  examples  of  such  drawings.  The  structure  exhibited 
m  the  latter  figure  formed  the  subject  of  a  paper  which  was  read  before 
•he  Royal  Society  during  the  present  year. 

Upper  Charlotte  Street,  Fitzroy  Square, 
November,  1M4. 


PREFACE 
TO  THE  FOURTH  LONDON  EDITION. 


IN  preparing  the  "  ANATOMIST'S  VADE  MECUM,"  for  the  fourth  time, 
for  the  Press,  the  Author  has  availed  himself  of  the  discoveries,  in  Ana- 
tomy, which  have  been  made  public  since  the  appearance  of  the  preceding 
edition ;  and  he  takes  the  opportunity,  now  afforded  him,  of  acknowledg- 
ing his  obligation  to  the  several  investigators  whose  researches  he  has 
quoted.  To  one  gentleman,  namely,  to  Mr.  PAGET  of  St.  Bartholomew's 
Hospital,  he  feels  particularly  indebted  for  the  assistance  which  he  has 
derived  from  the  excellent  "  Reports,  on  the  chief  results  obtained  by  the 
use  of  the  Microscope  in  the  study  of  Human  Anatomy  and  Physiology," 
published  in  the  British  and  Foreign  Medical  Review. 

In  the  present  edition  of  this  volume,  the  Wood-cut  Illustrations  have 
been  augmented  to  two  hundred ;  and  the  Author  begs  to  observe  that 
with  very  few  exceptions,  which  have  been  duly  acknowledged,  the  whole 
of  the  subjects  are  original ;  the  drawings  having  been  executed  by  Mr. 
BAGG  from  dissections  prepared  expressly  for  the  work,  or  from  drawings 
made  by  himself.  The  chief  of  the  illustrations  of  General  Anatomy  were 
drawn  from  the  microscope  with  the  camera  lucida,  in  order  to  ensure 
absolute  correctness. 


Upper  Charlotte  Street,  Fitzroy  Square, 
March  1,  1847. 


(iz) 


IX 

\ 


' 
PREFACE 

TO  THE  FOURTH  AMERICAN  EDITION. 


THE  Editor,  in  presenting  this  new  edition  of  Mr.  Wilson's  stanaard 
work  on  Anatomy,  has  found  but  little  to  add,  the  author  having  so  com 
pletely  revised  and  brought  up  his  last  edition  ;  while  he  has  incorporated 
in  the  text  many  of  the  Editor's  notes  to  former  editions. 

A  small  increase  in  the  size  of  the  page  has  enabled  the  Publishers  to 
take  in  the  additional  matter,  while  diminishing  slightly  the  number  of 
pages. 

The  Editor  has  added  some  new  matter  and  a  large  number  of  new  cuts — 
among  others  an  important  series  on  the  nerves — he  has  rewritten  his  in- 
troductory chapter  on  Histology;  and  he  has  taken  every  care  to  ensure, 
throughout,  perfect  correctness  in  the  text.  He  thus  hopes  that  the  work 
will  continue  to  hold  the  high  character  which  its  merits  have  acquired  in 
this  country,  and  to  maintain  its  position  as  a  standard  TEXT  BOOK  for  the 
student,  which  it  has  assumed  in  so  many  of  our  Colleges. 

The  London  edition  is  still  known  by  the  Author's  original  title  of 
"VADE  MECUM;"  but  the  publishers  consider  themselves  sustained  in 
the  change  they  have  made,  by  the  fulness  and  completeness  of  the  work, 
which  amply  warrant  for  it  the  title  of  "A  SYSTEM  OF  HUMAN  ANATOMY." 

P.  B.  G. 

• 

Philadelphia,  July,  1848. 

(xi) 


CONTENTS. 


CHAPTER  I. 


HISTOLOGY. 


Pa?e 

Definition 33 

Chemistry  of  the  tissues 33 

Nitrogenized  substances 35 

Non-nitrogenized  substances 36 

Of  the  tissues 37 

Tabular  view  of  the  tissues 37 

Description  of  the  tissues 38 


Pago 

Physical  properties 39 

Vital  properties 40 

Development  of  tissues 40 

Development  of  cells 41 

Multiplication  of  cells 41 

Transformation  of  cells  ..  ..42 


CHAPTER  II. 


OSTEOLOGY. 


Definition „  . . .  ,<M.. 43 

Chemical  composition  of  bone 43 

Division  into  classes 43 

Structure  of  bone 44 

Development  of  bone 46 

Period  of  ossification 48 

The  skeleton 49 

Vertebral  column 50 

Cervical  vertebrae 50 

Dorsal  vertebrae 53 

Lumbar  vertebrae 53 

General  considerations 54 

Development 55 

Attachment  of  muscles 56 

Sacrum     56 

Coccyx .    58 

The  skull 58 

Bones  of  the  cranium 58 

Occipital  bone 59 

2 


Paga 

Parietal  bone 61 

Frontal  bone 62 

Temporal  bone 64 

Sphenoid  bone 69 

Ethmoid  bone 72 

Bones  of  the  face 74 

Nasal 74 

Superior  maxillary ,  74 

Lachrymal  bone 77 

Malar  bone < 77 

Palate  bone 78 

Inferior  turbinated  bone 80 

Vomer 80 

Inferior  maxillary 81 

Table  of  developments,  articulations,  &c.  83 

Sutures 83 

Regions  of  the  skull 84 

Base  of  the  skull 86 

Face 89 

(xtu) 


XIV 


CONTENTS. 


Page 

Orbits 90 

Nasal  fossae 90 

Teeth 92 

Structure 93 

Development 95 

Growth 97 

Eruption 98 

Succession 99 

Os  hyoides 99 

Thorax  and  upper  extremity 100 

Sternum » ..  100 

Ribs 101 

Costal  cartilages 102 

Clavicle 103 

Scapula 1 03 

Humerus 105 

Ulna 106 

Radius  . .  .107 


Page 

Carpal  bones 109 

Metacarpal  bones 112 

Thalanges 113 

Pelvis  and  lower  extremity 114 

Os  innominatum 114 

Ilium 114 

Ischium 115 

Os  pubis 116 

Pelvis  —  Its  Divisions — Axes — Dia- 
meters   117,  118 

Femur 119 

Patella 121 

Tibia 121 

Fibula 122 

Tarsal  bones 124 

Metatarsal  bones 127 

Phalanges 128 

Sesamoid  bones..  .  129 


CHAPTER  III. 


THE   LIGAMENTS. 


Page 

forms  of  articulation 130 

Synarthrosis 130 

Amphi-arthrosis 1 30 

Diarthrosis 130 

Movements  of  joints 131 

Gliding 131 

Angular  movement 131 

Circumduction 131 

Rotation 132 

General  anatomy  of  articular  structures    132 

Cartilage 132 

True  cartilage 132 

Reticular  cartilage 132 

Fibrous  cartilage 134 

Fibrous  tissue 1 34 

Ligament 1 35 

Tendon 135 

Adipose  tissue 136 

Synovial  membrane 136 

LIGAMENTS  or  THE  TRUNK — ARRANGE- 
MENT   137 

Articulation  of  the  vertebral  column  ...  137 
Of  the  atlas  with  the  occipital  bone. .  140 
Of  the  axis  with  the  occipital  bone  . .  141 

Of  the  atlas  with  the  axis 141 

Of  the  lower  jaw 142 

Of  the  ribs  of  the  vertebrae. .  .144 


Of  the  ribs  with  the  sternum,  and  with 

each  other 145 

Of  the  sternum 146 

Of  the   vertebral   column,  with    the 

pelvis 146 

Of  the  pelvis 146 

LIGAMENTS  OF  THE  UPPER  EXTREMITY  149 

Sterno-clavicular  articulation 149 

Scapulo-clavicular  articulation 151 

Ligaments  of  the  scapula 151 

Shoulder  joint 152 

Elbow  joint , 152 

Radio-ulnar  articulation 153 

Wrist  joint 155 

Articulations  of  the  carpal  bones 156 

Carpo-metacarpal  articulation 156 

Metacarpo-phalangeal  articulation 157 

Articulation  of  the  phalanges 158 

LIGAMENTS  OF  THE  LOWER  EXTREMITY  158 

Hip  joint 158 

Knee  joint 159 

Articulation  between  the  tibia  and  fibula  163 

Ankle  joint 164 

Articulation  of  the  tarsal  bones 165 

Tarso-metatarsal  articulation 167 

Metatarso-phalangeal  articulation 1 67 

Articulation  of  the  phalanges 16is 


CONTENTS. 

CHAPTER  IV. 

THE   MUSCLES. 


Page 

General  anatomy  of  muscle 168 

Nomenclature — Structure 169 

MUSCLES  OF  THE  HEAD  AITD  FACE 173 

Arrangement  into  groups „ „  173 

Cranial  group — Dissection 174 

Occipito-frontalis * -  . . ..  174 

Orbital  group — Dissection 175 

Orbicularis  palpebrarum -  .  1 75 

Corrugator  supercilii 1 75 

Tensor  tarsi — Actions 176 

Ocular  group — Dissection 176 

Levator  palpebrae — Rectus  superior . .  177 
Rectus  inferior  —  Rectus  internus  — 

Rectus  externus -  . . .  177 

Obliquus  superior 178 

Obliquus  inferior — Actions 178 

Nasal  group „  .. ..  179 

Pyramidalis  nasi — Compressor  nasi..  179 
Dilatator  naris — Actions 179 

Superior  labial  group 180 

Orbicularis  oris — Levator  labii  superi- 

oris  alseque  nasi -  .  180 

Levator  labii  superioris  proprius 1 80 

Levator  anguli  oris — Zygomatici. . . .  180 
Depressor  labii  superioris  alaeque  nasi  181 
Actions 181 

Inferior  labial  group — Dissection 181 

Depressor  labii  inferioris 181 

Depressor  anguli  oris — Levator  labii 

inferioris 181,  182 

Actions 182 

Maxillary  group 182 

Masseter — Temporal  muscle 182 

Buccinator — External  pterygoid  mus- 
cle   183 

Internal  pterygoid  muscle 184 

Actions 184 

Auricular  group — Dissection 184 

AttoIIens  aurem 184 

Attrahens  aurem 185 

Retrahens  aurem — Actions 185 

MUSCLES  OF  THE  NECK 185 

A  rrangement  into  groups -  . .  185 

Superficial  group — Dissection 186 

Platysma  myoides „ 186 

Sterno-cleido-mastoideus 186 

Actions 187 

Depressors  of  the  os  hyoides  and  larynx  187 

Dissection „ 188 

Sterno-hyoideus  —  Sterno-thy  roideus .  188 

Thyro-hyoideus — Omo-hyoideus 188 

Actions 189 

Elevators  of  the  os  hyoides 189 

Dissection 189 

Digastricus  . .  .189 


Stylo-hyoideus  —  mylo-hyoideus  189,  190 
Genio-hyoideus — Genio-hyo-glossus— 

Actions 190 

Muscles  of  the  tongue 191 

Hyo-glossus — Lingualis 191 

Stylo-glossus 192 

Palato-glossus — Actions 192 

Muscles  of  the  pharynx — Dissection. . .  192 

Constrictor  inferior 192 

Constrictor  medius — Constrictor  supe- 
rior  193 

Stylo  -  pharyngeus  —  Palato-  pharyn- 

geus — Actions 193,  194 

Muscles  of  the  soft  palate — Dissection. .  194 
Levator  palati — Tensor  palati.  .  .194,  195 

Azygos  uvulae — Palato-glossus 195 

Palato-pharyngeus — Actions  ....  195,  196 

PrsBvertebral  muscles — Dissection 196 

Rectus  anticus  major — Rectus  anticus 

minor 19fi 

Scalenus  anticus 196 

Scalenus  posticus — Longus  colli....  197 

Actions 198 

Muscles  of  the  larynx 198 

MUSCLES  OF  THE  TBUXK - 198 

Muscles  of  the  back — Arrangement. ...  198 

First  layer — Dissection 199 

Trapezius 199 

Latissimus  dorsi 199 

Second  layer — Dissection 201 

Levator  anguli  scapulae 201 

Rhomboideus  minor  et  major 201 

Third  layer — Dissection 201 

Serratus  posticus  superior  et  infe- 
rior  201,  202 

Splenius  capitis  et  colli 202 

Fourth  layer — Dissection 202 

Sacro-lumbalis — Longissimus  dorsi  203 

Spinalis  dorsi _ 203 

Cervicalis  ascendens — Transversa- 

lis  colli 204 

Trachelo-mastoideus  —  Complexus  204 

Fifth  layer — Dissection 205 

Semi-spinalis  dorsi  et  colli 205 

Rectus  posticus,  major  et  minor. . .  205 
Rectus  lateralis — Obliquus  inferior 

et  superior 20  J/ 

Sixth  layer — Dissection 205 

Multifidus    spinae — Levatores  cos 

tarum 206 

Supra-spinalis — Inter-spinales  ....  206 

Inter-transversales .. .  206 

Actions 207 

Table  of  origins  and  insertions  of  the 

muscles  of  the  baok 208,  209 


XVI 


CONTENTS. 


Muscles  of  the  thorax 210 

Intcrcostales  externi  et  interni 210 

Triangularis  sterni — Actions 211 

Muscles  of  the  abdomen ....  211 

Dissection 211 

Obliquus  externus 212 

Obliquus  internus 214 

Cremaster 214 

Transversalis 215 

Rectus 216 

Pyramidalis — Quadratus  lumborum  .  216 

Psoas  parvus 216 

Diaphragm 217 

Actions 218 

Muscles  of  the  perineum 219 

Dissection 219 

Acceleratores  urina? 220 

Erector  penis 220 

Compressor  urethra 220 

Transversus  perinei 221 

Sphincter  ani  externus  et  internus. . .  222 

Levator  ani — Coccygeus 222 

Muscles  of  the  female  perineum  ....  222 
MUSCLES  OF  THE  UPPER  EXTREMITY.  .  223 

Anterior  thoracic  region 224 

Dissection   225 

Pectoralis  major  et  minor 225 

Subclavius — Actions 226 

Lateral  thoracic  region 226 

Serratus  magnus — Actions 226 

Anterior  scapular  region 226 

Subscapularis  , 226 

Actions 227 

Posterior  scapular  region 227 

Supra-spinatus — Infra-spinatus 227 

Teres  minor — Teres  major 227,  228 

Actions 228 

Acromial  region 228 

Deltoid — Actions 228 

Anterior  humeral  region — Dissection  . .  229 

Coraco-brachialis — Biceps 229 

Brachialis  anticus — Actions 230 

Posterior  humeral  region 230 

Triceps — Actions 231 

Anterior  brachial  region 231 

Superficial  layer — Dissection 231 

Pronator  radii  teres 231 

Flexor  carpi  radialis 232 

Palmaris  longus 232 

Flexor  sublimis  digitorum 232 

Flexor  carpi  ulnaris 233 

Deep  layer — Dissection 233 

Flexor  profundus  digitorum 233 

Flexor  longus  pollicis 233 

Pronator  quadratus — Actions  ....  234 

•Posterior  brachial  region 234 

Superficial  layer — Dissection   ....  234 

Supinator  longus 234 

Extensor  carpi  radialis  longior  . . .  235 
Extensor  carpi  radialis  brevior. . . .  235 
Extensor  comrnunis  digitorum. . . .  235 
Extensor  minimi  digit! 236 


Tags 
Extensor  carpi  ulnaris- -Anooneus  236 

Deep  layer — Dissection ...  236,  237 

Supinator  brevis 237 

Extensor  ossis  metacarpi  pollicis. .  237 
Extensor  primi  internodii  pollicis. .  237 
Extensor  secundi  internodii  pollicis  237 

Extensor  indicis — Actions 238 

Muscles  of  the  hand 238 

Radial  region — Dissection 238 

Ulnar  region — Dissection 239,  240 

Palmar  region 240 

Actions 242 

MUSCLES  OF  THE  LOWER  EXTREMITY.  242 

Gluteal  region — Dissection 243 

Gluteus  maximus  et  medius 244 

Gluteus  minimus 245 

Py  riformis 245 

Gemellus   superior — Obturator  inter- 
nus   245 

Gemellus  inferior  —  Obturator  exter- 
nus   246 

Quadratus  femoris — Actions 246 

Anterior  femoral  region — Dissection. . .  246 
Tensor  vagina?  femoris — Sartorius. . .  247 

Rectus — Vastus  externus 248 

Vastus  internus — Crureus — Actions.  248 
Internal  femoral  region — Dissection  . . .  249 

Iliacus  internus 249 

Psoas  magnus — Pectineus — Adduc- 
tor longus 249,  250 

Adductor   brevis — Adductor   magnus 

— Gracilis 250,  251 

Actions 251 

Posterior  femoral  region — Dissection  . .  25] 

Biceps  femoris 25 1 

Semi-tendinosus — Semi-membranosus 

— Actions 251 ,  252 

Anterior  tibial  region 253 

Dissection 253 

Tibialis  anticus 253 

Extensor  longus  digitorum 253 

Peroneus  tertius — Extensor   proprius 

pollicis 254 

Actions , 254 

Posterior  tibial  region 254 

Superficial  group — Dissection 254 

Gastroenemius 255 

Plantaris — Soleus — Actions 255 

Deep  layer — Dissection 255 

Popliteus — Flexor  longus  pollicis.  256 

Flexor  longus  digitorum 256 

Tibialis  posticus 257 

Actions 25V 

Fibular  region — Dissection 257 

Peroneus  longus — Peroneus  brevis  258 

Actions 258 

Foot — Dorsal  region 258 

Plantar  region 259 

First  layer — Dissection 259 

Second  layer — Dissection 261 

Third  layer — Dissection 261 

Fourth  layer — Actions 263 


CONTENTS. 


XVII 


CHAPTER  V. 


THE   FASCIA. 


Page 
General  anatomy 263 

FASCIJS  OF  THE  HEAD  AND  HECK 264 

Temporal  fascia 264 

Cervical  fascia 264 

FASCIA  OF  THE  TRUNK 265 

Thoracic  fascia 265 

Abdominal  fascia 266 

Fascia  transversalis 266 

Oblique  inguinal  hernia 266 

Congenital  hernia 267 

Encysted  hernia 267 

Direct  inguinal  hernia 268 


Page 

Fascia  iliaca 26S 

Fascia  pelvica 268 

Obturator  fascia 269 

Superficial  perineal  fascia 269 

Deep  perineal  fascia 269 

FASCTJB  or  THE  UPPER  EXTREMITY  ...  271 

FASCIA  OF  THE  LOWER  EXTREMITY.  .  .    272 

I  Fascia  lata 272 

j  Femoral  hernia 273 

Fascia  of  the  leg 274 

Plantar  fascia  . ,  . .  274 


CHAPTER  VI. 


THE   ARTERIES. 


Page 

General  anatomy  of  arteries 275 

Inosculations — Structure 276,  277 

Aorta 278 

Table  of  branches 281 

Coronary  arteries 281 

Arteria  innorninata 281 

Common  carotid  arteries 2.82 

External  carotid  artery 283 

Table  of  branches 284 

Superior  thyroid  artery 284 

Lingual  artery 285 

Facial  artery 285 

Mastoid  artery 287 

Occipital  artery 287 

Posterior  auricular  artery 287 

Ascending  pharyngeal  artery  ...'....  287 

Parotidean  arteries 287 

Transverse  facial  artery 287 

Temporal  artery 288 

Internal  maxillary 288 

Internal  carotid  artery 291 

Ophthalmic  artery 292 

Anterior  cerebral  artery 293 

Middle  cerebral  artery 294 

Subclavian  artery 294 

Table  of  branches 296 

Vertebral  artery 296 

Basilar  artery 296 

Circle  of  Willis 297 

Thyroid  axis 298 

Inferior  thyroid  artery 298 

Supra-scapular  artery 298 

Posterior  scapular 299 

Ruperficialis  crrvicis 299 

2* 


Page 

Profundis  cervicis 299 

Superior  intercostal  artery — Internal 

mammary  ;  branches 299 

Axillary  artery 300 

Table  of  branches 301 

Brachial  artery 303 

Radial  artery 304 

Ulnar  artery 306 

Thoracic  aorta  ;  branches 308 

Abdominal  aorta  ;  branches 309 

Phrenic  arteries 309 

Coeliac  axis 310 

Gastric  artery 310 

Hepatic  artery 310 

Splenic  artery 311 

Superior  mesenteric  artery 312 

Spermatic  arteries 314 

Inferior  mesenteric  artery 315 

Renal  arteries 315 

Lumbar  arteries 315 

Sacra  media 316 

Common  iliac  arteries 316 

Internal  iliac  artery 317 

Ischiatic 318 

Internal  pudic  artery 318 

External  iliac  artery 321 

Femoral  artery 323 

Popliteal  artery 326 

Anterior  tibial  artery 32& 

Dorsalis  pedis  artery 329 

Posterior  tibial  artery 330 

Peroneal  artery 331 

Plantar  arteries 332 

Pulmonary  artery 334 


XV111 


CONTENTS. 


CHAPTER  VII. 


THE   VEINS. 


Page 

General  anatomy 334 

Veins  of  the  head  and  neck ......  336 

Veins  of  the  diploe 337 

Cerebral  and  cerebellar  veins 338 

Sinuses  of  the  dura  mater 338 

Veins  of  the  neck 341 

Veins  of  the  upper  extremity 342 

Veins  of  the  lower  extremity 344 

Veins  of  the  trunk . .  344 


Vens  innominate 345 

Superior  vena  cava , 345 

Iliac  veins 345 

Inferior  vena  cava 346 

Azygos  veins 343 

Vertebral  and  spinal  veins 348 

Cardiac  veins 349 

Portal  system 349 

Pulmonary  veins 351 


CHAPTER  VIII. 


THE   LYMPHATICS. 


Page 
General  anatomy 351 

Lymphatics  of  the  head  and  neck 353 

Lymphatics  of  the  upper  extremity  ....  354 
Lymphatics  of  the  lower  extremity  ....  355 
Lymphatics  of  the  trunk 356 


Page 
Lymphatics  of  the  viscera. ...........  357 

Lacteals 358 

Thoracic  duct 359 

Ductus  lymphaticus  dexter 360 


CHAPTER  IX. 


THE   NERVOUS   SYSTEM. 


Page 

General  anatomy 361 

The  brain 367 

Membranes  of  the  encephalon 368 

Dura  mater 369 

Arachnoid  membrane 370 

Pia  mater .- 371 

Cerebrum 372 

Lateral  ventricles 373 

Fifth  ventricle 376 

Fornix 378 

Thalami  optici , .  378 

Third  ventricle 378 

Corpora  quadrigemina 379 

Pineal  gland 379 

Fourth  ventricle 380 

Lining  membrane  of  the  ventricle. . .  380 

Cerebellum 381 

Base  of  the  brain  . .  . .  382 


Pape 

Medulla  oblongata 385 

Diverging  fibres 386 

Converging  fibres ;  commissures 388 

Spinal  cord 389 

Cranial  nerves 392 

Spinal  nerves 409 

Cervical  plexus 411 

Brachial  plexus 414 

Dorsal  nerves 420 

Lumbar  nerves - .  422 

Sacral  nerves 426 

Sympathetic  system 433 

Cranial  ganglia 433 

Cervical  ganglia 437 

Thoracic  ganglia 440 

Lumbar  ganglia 441 

Sacral  ganglia 442 


CONTENTS. 


XIX 


CHAPTER  X. 


ORGANS    OF    SENSE. 


. 

Nose 442 

Nasal  fossse 444 

Eyeball 445 

Sclerotic  coat  and  cornea 445 

Choroid  coat;  ciliary  ligament;  iris  .  447 

Retina ;  zonula  ciliaris 449 

Humours 451 

Physiological  observations 452 

Appendages  of  the  eye 453 

Lachrymal  apparatus 455 

Organ  of  hearing 456 

External  ear  ;  pinna 456 

Meatus  auditorius . .  457 


Page 
Organ  of  hearing — continued. 

Tympanum 458 

Ossiculi  auditus 458 

Muscles  of  the  tympanum 459 

Internal  ear 461 

Vestibule 462 

Semicircular  canals — Cochlea 463 

Membranous  labyrinth 465 

Organ  of  taste — Tongue 4C7 

Organ  of  touch — Skin 468 

Appendages  of  the  skin — Nails 472 

Hairs — Sebiparous  glands 474 

Sudoriparous  glands 474 


CHAPTER  XI. 


THE   VISCERA. 


Pa<re 

THORAX 475 

Heart 475 

Structure  of  the  heart 482 

Organs  of  respiration  and  voice 485 

Larynx — Cartilages 485 

Ligaments    486 

Muscles 488 

Trachea  and  Bronchi 491 

Thyroid  gland 492 

Lungs 492 

Pleura 495 

Mediastinum 496 

ABDOMEN — Regions 496 

Peritoneum 497 

Alimentary  canal 501 

Lips — Cheeks — Gums — Palate 502 

Tonsils  — Fauces 503 

Salivary  glands 503 

Pharynx 504 

Stomach 505 

Small  intestine 506 

Large  intestine 507 

Structure  of  the  intestinal  canal  ....  509 


Page 

ABDOMEN — continued. 

Liver 515 

Gall-bladder 525 

Pancreas 526 

Spleen 526 

Supra-renal  capsules 527 

Kidneys 528 

PELVIS 532 

Bladder 532 

Prostate  gland 534 

Vesicular  seminales 535 

MALE  ORGANS  OF  GENERATION 536 

Penis   536 

Urethra 537 

Testes 541 

FEMALE  PELT  is 544 

Bladder— Urethra 544 

Vagina 545 

Uterus 546 

Fallopian  tubes 549 

Ovaries 549 

External  organs  of  generation 550 

MAMMARY  GLANDS  . .  ....  551 


CHAPTER  XII. 


ANATOMY    OF   THE   F02TTJS. 


Osseous  and  ligamentous  system 553 

Muscula^  system 553 

Vascu.ar  system 553 

Fostal  circulation 553 

Nervous  system 555 

Organs  of  Sense — Eye — Ear — Nose...  555 

Thyroid  gland 556 

Thymus  gland 556 


Pare 

Fcetal  lungs 558 

Foetal  heart 559 

Viscera  of  the  abdomen 559 

Omphalo-mesenteric  vessels 559 

Fcetal  liver 560 

Kidneys  and  supra-renal  capsules  . . .  560 

Viscera  of  the  pelvis 560 

Testes — Descent 560 


TABLE  OF  ILLUSTRATIONS. 


rigs, 
i. 
2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 
10. 
11. 
12. 
13. 
14. 
15. 
16. 
17. 
18. 
19. 
20. 
21. 
22 
23. 
24. 
25. 
26. 
27. 
28. 
29. 
30. 

31. 
32. 

33. 
34. 
35. 
36. 
37. 
38. 
39. 
40. 
41. 
42. 

43. 
44. 
45 


Page 

Vegetable  nucleated  cells 37 

Growth  of  cells 4] 

Reproduction  of  cells 41 

Implantation  of  cells 41 

Transformation  of  cells 42 

/   Changes  in  formative  cells  of 

f       an  animal 42 

Id.  of  a  vegetable 42 

Formation  of  fibres 42 

Minute  structure  of  bone 44 

Id.  id.  id 45 

Development  of  bone 47 

Id.  id , 47 

Id.  id 47 

Cervical  vertebra 51 

Atlas 51 

Axis 52 

Dorsal  vertebra 53 

Lumbar  vertebra 53 

Sacrum 57 

Occipital  bone — External  surface  .  59 

Occipital  bone — Internal  surface  . .  60 

Parietal  bone — External  surface  . .  61 

Parietal  bone — Internal  surface. . .  62 

Frontal  bone — External  surface  . .  63 

Frontal  bone — Internal  surface. ..  63 

Temporal  bone — External  surface.  64 

Temporal  bone — Internal  surface  .  66 
Meatus  auditorius  externus  and  in- 

ternus,  and  tympanic  bone 66 

Sphenoid  bone — Superior  surface  .  69 
Sphenoid  bone  —  Antero-inferior 

surface 70 

Ethmoid  bone 73 

Superior  maxillary  bone 74 

Lachrymal  bone f 77 

Palate  bone — Internal  surface  ....  78 

Palate  bone — External  surface  ...  79 

Inferior  maxillary  bone 82 

Skull,  anterior  view 85 

Base  of  the  skull ;  internal  view  . .  85 

Base  of  the  skull;  external  view. .  87 
Nasal  fossa  with  the  turbinated 

bones 91 

Permanent  teeth 92 

Temporary  teeth 93 

Section  of  molar  tooth  . .  .94 


Figs.  Pag« 

46.  Capsule  of  temporary  incisor 97 

47.  Temporary  tooth  with   capsule  of 

permanent 98 

48.  Os  hyoides 99 

49.  Thorax 101 

50.  Scapula 04 

51.  Humerus ,.  ,.06 

52.  Ulna  and  radius 108 

53.  Bones  of  the  carpus;  posterior  view  109 

54.  Hand  ;  anterior  view Ill 

55.  Os  innominatum 114 

56.  Female  pelvis  ;  anterior  view  ....  117 

57.  Femur ;  anterior  view 119 

58.  Femur ;  posterior  view 120 

59.  Tibia  and  fibula;  anterior  view. . .  122 

60.  Tibia  and  fibula  ;  posterior  view. .  123 

61.  Foot ;  dorsal  surface 125 

62.  Foot ;  plantar  surface 128 

63.  Articular  cartilage 132 

64.  Id.  id 132 

65.  Id.  id 133 

66.  Reticular  cartilage 1 33 

67.  Fibrous  cartilage 133 

68.  White  fibrous  tissue ,  . .  134 

69.  Yellow  fibrous  tissue 135 

70.  Adipose  tissue 136 

71.  Epithelium  of  serous  membrane. .  137 

72.  Ligaments  of  the  vertebrae  and  ribs ; 

anterior  view 138 

73.  Posterior  common  ligament 138 

74.  Ligamenta  subflava 139 

75.  Ligaments  of  the  atlas,  axis,  and 

occipital  bone 140 

76.  Id. ;  posterior  view 140 

77.  Id. ;  internal  view 141 

7*8.  Id. ;  internal  view 142 

79.  Ligaments  of  the  lower  jaw  ;  ex- 

ternal view 143 

80.  Id. ;  internal  view 143 

81.  Id ;  section 144 

82.  Ligaments  of  the  vertebral  column 

and  ribs 145 

83.  Ligaments  of  the  pelvis  and  hip  joint  148 

84.  Id.  id.  id....  148 

85.  Ligaments  of  the  sternal  end  of  the 

clavicle  and  costal  cartilages. ...  150 

86.  Ligaments    of    the    scapula    and 

shoulder  joint 151 

(xxil 


XXII 


TABLE    OF    ILLUSTRATIONS. 


Figs.  Page 

87.  Ligaments  of  the  elbow  ;  internal 

view 153 

88.  Id. ;  external  view 153 

89.  Radio-ulnar  articulation 154 

90.  Ligaments  of  the  wrist  and  hand.  155 

91.  Synovial  membranes  of  the  wrist. .  157 

92.  Knee  joint;  anterior  view 160 

93.  Id. ;   posterior  view 161 

94.  Knee  joint ;  internal  view 161 

95.  Id. ;    reflexions    of    the   synovial 

membrane 162 

96.  Ankle  joint ;  internal  view 1 64 

97.  Id.;   external  view 164 

98.  Id. ;  posterior  view 166 

99.  Ligaments  of  the  sole  of  the  foot. .  167 

100.  Minute  structure  of  muscle 170 

101.  Id.  id. 170 

102.  Id.  id 171 

103.  Id.  id 171 

104.  Id.  id 172 

105.  Muscles  of  the  face 1 74 

106.  Tensor  tarsi 176 

107.  Muscles  of  the  orbit 176 

108.  Pterygoid  muscles 184 

109.  Muscles   of  the  neck;   superficial 

and  deep 186 

110.  Muscles  of  the  tongue 191 

111.  Muscles  of  the  pharynx 194 

112.  Muscles  of  the  soft  palate 1 05 

113.  Muscles  of  the  praevertebral  region    197 

114.  Muscles  of  the  back;   1st,  2d,  and 

3d  layer 200 

115.  Muscles  of  the  back  ;  deep  layer. .  203 

116.  Muscles  of  the  anterior  aspect  of 

the  trunk 213 

117.  Muscles  of  the  lateral  aspect  of  the 

trunk... 215 

118.  Diaphragm 218 

119.  Muscles  of  the  perhieum 221 

120    Muscles  of  the  anterior  humeral  re- 
gion  229 

121.  Triceps  extensor  cubiti 230 

122.  Superficial  layer  of  muscles  of  the 

anterior  aspect  of  the  fore-arm. .  231 

123.  Deep  layer  of  muscles  of  the  ante- 

rior aspect  of  the  fore-arm 234 

124.  Superficial  layer  of  muscles;  poste- 

rior aspect  of  the  fore-arm 235 

125.  Deep  layer  ;  posterior  aspect  of  the 

fore-arm 237 

126.  Muscles  of  the  hand,  anterior  aspect  239 

127.  Palmar  interossei 241 

128.  Dorsal  interossei 241 

129.  Muscles  of  the  gluteal  region,  deep 

layer 244 

130.  Muscles  of  the  anterior  and  internal 

femoral  region 247 

131.  Muscles  of  the  gluteal  and  posterior 

femoral  region 252 

132.  Muscles   of  the  anterior  tibial  re- 

gion  253 

133.  Muscles  of  the  posterior  tibial  re- 

gion   255 


Fiss.  Pag« 

1 34.  Muscles  of  the  posterior  tibial  region, 

deep  layer 256 

135.  Dorsal  interossii 259 

136.  Muscles  of  the  sole  of  the  foot ;   1st 

layer 259 

137.  Muscjes  of  the  sole  of  the  foot;  2d 

layer 260 

138.  Deep-seated  muscles 261 

139.  Plantar  interossii 263 

140.  Section  of  the  neck,  showing  the 

distribution  of  the  deep  cervical 
fascia 265 

141.  Transverse  section    of  the   pelvis, 

showing  the  distribution  of  the 
fasciae 269 

142.  Deep  perineal  fascia   270 

143.  Distribution  of  the   deep  perineal 

fascia  ;  side  view 270 

144.  Distribution    of  the  fascia?    at   the 

femoral  arch 273 

145.  The  great  vessels  of  the  chest 278 

146.  Branches   of  the  external    carotid 

artery ' 284 

147.  External  carotid  .  <. 289 

148.  Branches  of  the  subclavian  artery.  296 

149.  The  circle  of  Willis 298 

150.  Axillary  and  brachial  arteries  ....  301 

151.  Arteries   pf   the    fore-arm — Radial 

and  ulnar 304 

152.  Branches  of  the  abdominal  aorta.  .310 

153.  Cojliac  axis  with  its  branches. . . .  312 

154.  The  superior  mesenteric  artery  . . .  313 

155.  The  inferior  mesenteric  artery. ...  314 

156.  The  internal  iliac  artery  with  its 

branches 317 

157.  The  arteries  of  the  perineum 319 

1 58.  The  femoral  artery  with  its  branches  323 

159.  The  anterior  tibial  artery 328 

160.  Posterior  tibial  and  peroneal  artery  330 

161.  Arteries  of  the  sole  of  the  foot 332 

162.  Sinuses  of  the  dura  mater 339 

163.  Sinuses  of  the  base  of  the  skull. . .  340 

164.  Veins  and  nerves  of  the  bend  of  the 

elbow 342 

165.  Veins  of  the  trunk  and  neck 346 

166.  The  portal  vein 350 

167.  The  thoracic  duct 360 

168.  Minute  structure  of  nerve 363 

169.  The  centrum  ovale  inajus  and  cor- 

pus callosum 373 

170.  The  lateral  ventricles  of  the  cere- 

brum   374 

171.  Longitudinal  section  of  the  brain. .  377 

172.  Base  of  the  brain 384 

173.  Distribution  of  the  fibres  of  the  brain  387 

174.  Sections  of  the  spinal  marrow  ....  391 

175.  Sections  of  the  spinal  cord 392 

176.  The  olfactory  nerve 393 

177.  Origin  of  the  optic  and  fourth  nerves  394 

178.  The  isthmus  encephali,  showing  the 

thalamus  opticus,  corpora  quaclri- 
gemina,  pons  Varolii,  and  medulla 
oblongata 39* 


TABLE    OF   ILLUSTRATIONS. 


XX111 


Pips.  Page 

179.  Third,  4th,  and  5th  pair  of  nerves    396 

180.  Trifacial  or  fifth  nerve 397 

181.  Portio  mollis  of  7th  pair 401 

182.  Facial  and  cervical  nerves .  403 

183.  Eighth  pair  of  nerves 400 

184.  Hypoglossal  or  ninth  nerve 408 

185.  Part  of  the  cervical  portion  of  the 

spinal  cord 410 

186.  Axillary  plexus  and  nerves  of  the 

upper  extremity 414 

187.  Nerves  of  front  of  fore-arm 417 

188.  Nerves  of  back  of  fore-arm 418 

189.  Lumbar  and  sacral  plexus,  with  the 

nerves  of  the  lower  extremity . . .  422 

190.  Anterior  crural  nerve 424 

191.  Branches  of  ischiatic  plexus 427 

192.  id.         popliteal  nerve 430 

1 93.  Posterior  tibial  nerve 430 

194.  Nerves  of  sole  of  foot 431 

195.  Anterior  tibial  nerve 432 

196.  The  cranial  ganglia  of  the  sympa- 

thetic nerve 434 

197.  Great  sympathetic 439 

198.  Fibro-cartilages  of  the  nose 443 

199.  Longitudinal  section  of  the  globe 

of  the  eye 446 

200.  Vense  vorticosse  of  choroid  coat . . .  448 

201.  A  transverse  section  of  the  globe  of 

the  eye 449 

202.  Another  transverse  section  of  the 

globe  of  the  eye 449 

203.  Auxiliary  parts  of  eye 453 

204.  A  diagram  of  the  ear 458 

205.  Anatomy  of  the  cochlea 464 

206.  Osseous  and  membranous  labyrinth 

of  the  ear 464 

207.  PapilliE  of  tongue 467 

208.  Anatomy  of  the  skin 469 

209.  Development  of  epidermis 470 

210.  Anatomy  of  the  skin 473 

211.  The  heart 476 

212.  Anatomy  of  the  heart,  right  side  . .  478 


Pigs.  Page 

213.  Anatomy  of  the  heart,  left  side  . . .  482 

214.  Ligaments  of  the  larynx 487 

215.  Muscles  of  the  larynx 488 

216.  Id.  id 489 

217.  Anatomy  of  the  lungs  and  heart. .  493 

218.  Viscera  of  abdomen 497 

219.  The  peritoneum 498 

220.  The  pharynx 505 

221.  Anatomy  of  the  stomach  and  duo- 

denum   506 

222.  Csecum  and  appendix 508 

223.  Section  of  anus 510 

224.  Peyer's  glands 513 

225.  Section  of  parietes  of  anus 514 

226.  The  liver;  its  upper  surface 516 

227.  The  liver ;  its  under  surface 517 

228.  Lobules  of  the  liver 519 

229.  Id.  id 519 

230.  Section  of  superficial  lobules 520 

231.  Id.  id 521 

232.  Section  of  the  kidney 529 

233.  Plan  of  the  renal  circulation 531 

234.  A  side  view  of  the  viscera  of  the 

male  pelvis 533 

235.  A  posterior  view  of  the  bladder  and 

vesiculae  seminales 535 

236.  Anatomy  of  the  urethra 538 

237.  Prostatic  urethra 539 

238.  Transverse  section  of  the  testicle. .  541 

239.  Anatomy  of  the  testis  543 

240.  Injected  testis 544 

241.  A  side  view  of  the  viscera  of  the 

female  pelvis 545 

242.  Uterus  and  Fallopian  tubes 546 

243.  Section  of  uterus 547 

244.  Female  external  organs  of  genera- 

tion   550 

245.  Fcetal  circulation 554 

246.  Section  of  the  thymus  gland 557 

247.  Ducts  of  the  thymus  gland 557 

248-9.  Descent  of  the  testis  in  the  foetus  561 


0  V,  / 


Vfrtt 


SYSTEM  OE  HUMAN  ANATOMY, 


CHAPTER   I. 

INTRODUCTORY. 

BY    THE     EDITOH. 

ANATOMY  (derived  from  avarsftveiv,  to  dissect)  is  the  science  which 
teaches  the  structure  and  relation  of  the  different  parts  of  an  organized 
body.  Organized  bodies  are  divided  into  animal  and  vegetable  ;  hence 
we  have  animal  and  vegetable  anatomy,  the  latter  being  closely  allied  to 
botany. 

An  organized  body  consists  of  an  assemblage  of  parts  called  organs, 
which  have  a  mutual  relation  to,  and  dependence  upon  each  other  ;  each 
doing  its  part  to  sustain  the  organism  which  they  compose.  The  descrip- 
tion of  the  form,  colour  and  position  of  these  organs  is  the  province  of 
special  anatomy;  whilst  their  relations  to  each  other,  and  the  knowledge 
of  the  number  and  arrangement  of  organs  in  particular  parts,  constitutes 
regional  or  topographical  anatomy,  which,  when  taught  with  reference  to 
surgical  operations,  is  usually  designated  by  the  title  of  surgical  anatomy. 
When  these  organs  are  carefully  examined,  they  are  found  to  consist  of  a 
number  of  different  structures  which  serve  to  build  up  and  constitute 
them.  These  are  called  tissues,  and  are  either  general,  existing  in  all  the 
organs,  or  special  and  peculiar,  and  found  only  in  certain  of  them,  giving 
them  their  appropriate  characters.  The  knowledge  of  tissues,  their  form, 
colours,  constituents,  origin  and  uses,  constitutes  histology ;  which,  com- 
mencing with  Bichat  in  1790,  has  now  attained  such  an  extent  and  im- 
portance as  to  constitute  almost  a  new  science,  and  to  correct  and  bring 
nearer  to  perfection  the  hypotheses  of  its  sister  science,  physiology. 

An  animal  body  or  organism  consists  of  solids,  which  differ  in  density 
and  hardness,  in  consequence  of  being  more  or  less  mingled  with  and  di- 
luted by  the  fluids  which  permeate  them. 

By  the  agency  of  chemistry  we  may  separate  both  solids  and  fluids  into 
proximate  and  ultimate  elements,  and  hope  by  this  means  to  obtain  a 
more  intimate  acquaintance  with  their  structure  and  use ;  but  if  this  is 
done  with  the  masses  as  is  usual  in  chemical  analyses,  and  not  upon  the 
tissues  separated  from  each  other  by  the  aid  of  the  microscope,  it  will 
confer  upon  us  about  as  much  real  and  useful  information,  as  the  analysis 
\vhich  a  scientific  but  witty  English  chemist  once  made  of  a  whole  mouse. 

The  principal  ultimate  elements  of  an  animal  body  obtained  by  the  pro- 
cesses of  chemical  analysis  are — 

Oxygen,  hydrogen,  carbon,  and  nitrogen,  which  form  almost  the  whole 
oulk  of  the  fluids  and  soft  solids  ;  but  to  these  must  be  added  a  number 


34  HISTOLOGY. 

of  others,  which,  although  they  exist  in  smaller  proportions,  still  form  im- 
portant constituents  of  peculiar  tissues.     Thus  we  find — 

Lime,  or  its  base,  calcium,  combined  with  the  carbonic  or  phosphoric 
acids,  in  the  bones  and  teeth. 

Magnesia,  in  the  sebaceous  matter  of  the  skin. 

Alumina,  in  the  enamel  of  the  teeth ; 

And  iron,  in  the  black  pigment  in  various  parts. 

The  additional  elements  thus  brought  into  the  organism  may  be  enume- 
rated as  follows : 

Metallic  bases  of  earths. — Calcium,  magnesium,  silicium,  aluminum. 
Metallic  bases  of  alkalies. — Potassium,  sodium. 
Phosphorus,  sulphur,  chlorine,  and  fluorine. 
Metals. — Iron,  manganese,  titanium,  arsenic,  and  copper. 
Almost  all  of  these  elements  -exist  compounded  in  either  the  binary  or 
ternary  form. 

The  binary  compounds  are — 

Water,  found  universally  consisting  of  HO. 
Carbonic  acid,  found  in  blood,  urine,  sweat. 

Carbonates,  or  salts  of  carbonic  acid : — 

Carbonate  of  soda,  in  serum,  bile,  mucus,  sweat,  saliva,  tears,  carti- 
lage, &c. 

Carbonate  of  ammonia,  in  the  amniotic  liquor,  probably  derived  from 
the  urine  of  the  foetus. 

Carbonate  of  lime,  in  cartilage,  bone,  and  the  teeth. 

Carbonate  of  magnesia,  in  the  sebaceous  matter  of  the  skin. 

Salts  of  phosphoric  add : — 

Phosphate  of  soda,  in  serum,  saliva,  sweat,  bones,  muscles,  &c. 

Phosphate  of  lime,  in  bones,  teeth,  cartilage,  and  the  sandy  concretions 
ot  the  pineal  gland. 

Phosphate  of  soda  and  ammonia,  in  urine  and  blood;  but  probably  only 
for  the  purpose  of  being  excreted  or  thrown  off  as  unfit  to  constitute  a 
part  of  an  animal  body. 

Phosphate  of  iron,  in  blood,  gastric  juice,  and  urine. 

Chlorine  and  its  compounds : — 

Hydrochloric  acid,  in  gastric  juice,  and  in  the  fluid  of  the  caecum. 
Chloride  of  sodium,  in  blood,  brain,  muscle,  bone,  cartilage,  dentine, 
and  pigment. 

Chloride  of  potassium,  in  blood,  gastric  juice,  milk,  saliva. 
Chloride  of  ammonium,  in  sweat,  gastric  juice. 
Chloride  of  calcium,  in  gastric  juice. 

Sulphuric  acid  and  its  compounds : — 

Sulphate  ofpotassa,  in  urine,  gastric  juice,  and  cartilage. 

Sulphate  of  soda,  in  sweat,  bile,  and  cartilage. 

Sulphate  of  lime,  in  bile,  hair,  and  cuticle. 

Sulpho-cyanide  ofpotassa,  in  the  saliva. 

Fluoride  of  calcium,  in  the  enamel. 

Silica  and  oxide  of  manganese,  in  the  hair. 

Alumina,  in  the  enamel. 


HISTOLOGY.  35 

Oxide  of  iron,  in  blood,  black  pigment,  lens,  and  hair. 

Oxide  of  titanium,  in  the  capsulse  renales. 

Jlmmonia  and  cyanogen  only  exist  in  excreted  liquids,  and  conse- 
quently do  not  appear  fit  to  form  any  part  of  an  organism,  one  consisting 
of  NH  and  the  other  of  CH ;  their  elements  may  only  have  united 
for  the  purpose  of  finding  a  ready  exit  from,  the  body  through  the  emunc- 
tories. 

Chemistry  and  physiology  have  both  failed  to  detect  the  mode  in 
which  the  elements  of  an  animal  body  form  themselves  into  the  ternary 
and  quaternary  compounds  which  are  found  or  supposed  to  exist  in  them, 
and  much  confusion  and  uncertainty  still  prevail  in  regard  to  their  compo- 
sition and  the  part  they  play  in  the  animal  organization.  Almost  all  of 
these  compounds  contain  nitrogen,  in  addition  to  the  carbon,  oxygen  and 
hydrogen  found  in  them ;  and  some  of  them  are  exactly  alike  in  their  ele- 
mentary chemical  constitution,  although  differing  in  a  remarkable  manner 
in  their  sensible  characteristics.  Those  ternary  or  quaternary  compounds 
which  contain  nitrogen  are  prone  to  rapid  putrescence,  and  have  received 
the  generic  name  of  nitrogenized  substances. 

I.  NITROGENIZED  SUBSTANCES.  —  Perhaps  the  best  mode  of  explain- 
ing these  compounds  is  to  admit  the  existence  of  PROTEIN,  which  is 
described  by  Mulder,  and  is  so  called  because,  itself  a  primary  sub- 
stance, it  originates  so  many  dissimilar  substances.  It  consists  of  C^ 
H3]  N5  0^.  By  imagining  it  to  unite  with  small  proportions  of  either 
sulphur  or  phosphorus,  or  both,  it  may  be  said  to  form  a  number  of  ni- 
trogenized bodies.  When  in  the  moist  state,  protein  is  said  to  be  gelatin- 
ous, and  when  dried,  brittle,  and  of  a  brownish  colour.  It  is  inodorous 
and  tasteless,  insoluble  in  water,  alcohol,  or  ether,  but  easily  dissolved  by 
all  the  acids  in  a  dilute  state. 

The  substances  formed  by  it  are — 

1st.  Albumen  (Pr10-fPS2).  TJiis  substance  is  exceedingly  common 
in  the  animal  economy,  and  a  good  example  of  it  is  presented  in  the 
white  of  an  egg,  which  is  nearly  pure  albumen.  It  forms  an  admirable 
matrix  or  blastema  for  the  generation  of  cells,  and  the  consequent  forma- 
tion of  tissues.  When  dry,  albumen  is  solid,  brittle,  and  of  an  amber 
yellow  colour.  It  is  soluble  in  water,  coagulable  by  heat,  alcohol  and 
acids,  and  forms  insoluble  compounds  with  tannin,  sugar  of  lead,  and 
corrosive  sublimate. 

Very  nearly  resembling  albumen  in  many  of  its  properties  is — 

2d.  Fibrin  (Pr10  +  PS).  This,  however,  possesses  the  power  of  coagu- 
lating, when  removed  from  the  body  of  a  living  animal,  in  from  three  to 
seven  minutes,  into  a  delicate  rete  or  net-work.  It  is  most  readily  ob- 
tained from  blood,  where  it  exists  in  solution,  by  whisking  it  with  a  bundle 
of  twigs,  which  hastens  its  coagulation,  and  causes  it  to  adhere  to  the 
twigs.  When  well  washed  with  running  water  it  presents  a  semi-solid 
condition,  a  dull  yellowish  colour,  and  scarcely  an  appreciable  odour. 
Fibrin,  in  a  coagulated  state,  forms  almost  the  whole  bulk  of  the  muscles. 

3d.  Casein  (Pr10  +  S).  This  substance  is  abundantly  found  in  milk, 
and  constitutes,  when  dried,  cheese.  It  is  soluble  in  water,  and  coagu- 
lated by  alcohol,  acids,  and  the  stomarh  of  any  of  the  mammalia.  Be 


30  HISTOLOGY. 

sides  forming  a  constituent  of  milk,  casein  is  found  in  blood,  saliva,  bile, 
and  the  lens  of  the  eye. 

4th.  Pepsin.  This  substance  was  discovered  by  Schwann,  and  analysed 
by  Vogel,  who  found  it  to  be  composed  of  C^  Hja  N8  010.  It  is  so 
much  like  albumen  that  it  is  difficult  to  discover  a  distinction  between 
them.  It  is  found  in  the  gastric  elands. 

5th.  Globulin  (Pr13-f  S)  exists  in  the  blood  corpuscles;  very  like  albu 
men. 

6th.  Spermatin  is  found  in  semen ;  probably  fibrin,  altered  and  filled 
with  living  forms. 

7th.  Mucus  consists  of  globules  floating  in  a  clear  fluid,  the  constitution 
of  each  being  different. 

8th.  Keratin  (Pr  S2).  The  product  of  the  analysis  of  hair,  cuticle,  &c. 

9th.  Salivin.  Found  only  in  the  saliva. 

Besides  the  protein  compounds  thus  enumerated,  we  have  the  extractive 
matter,  obtained  by  either  water  or  alcohol  from  muscular  flesh. 

The  watery  extract  is  called  osmazome,  is  highly  volatile,  gives  the 
taste  and  odour  to  soups  and  roast  meats,  and  is  no  doubt  a  product  of 
the  treatment  of  the  meat,  or  a  new  combination  of  the  animal  elements 
occurring  during  the  effort  to  procure  it. 

Gelatine  is  another  substance  obtained  from  portions  of  the  animal 
body,  and  differs  according  to  the  tissue  which  furnishes  it.  Thus  ten- 
dons, ligaments  and  bone  furnish  colla,  or  glue,  which  consists  of  C52 
H40  N8  O^) ;  whilst  the  cartilages  and  the  cornea  furnish  chondnn,  the 
composition  of  which  is  N^  H^  N4  014. 

Hematin  is  found  in  C4t  H^  N3  O6  united  with  a  little  iron,  which  is 
not  essential  to  its  composition  or  existence. 

A  number  of  principles  have  been  described  as  existing  in  the  hepatic 
secretion  or  bile,  but  much  research  is  yet  necessary  to  clear  up  the  con- 
fusion which  exist  in  wrritings  with  regard  to  them.  They  may  be  enu- 
merated : — Bilin,  fellinic  acid,  cholinic  acid,  taurin,  dyslysin,  cholepyrrhin, 
biliphcein,  biliverdin,  bUifulvin,  cholesterin,  oleate,  mangarate,  and  stearate 
of  soda,  chloride  of  sodium,  sulphate,  phosphate,  and  lactate  of  soda,  and 
phoxphate  of  lime. 

Urea  and  uric  acid,  found  in  the  urine,  should  not  be  considered  as 
constituent  parts  of  an  animal,  but  as  elements  combined  in  a  particular 
way  for  the  purpose  of  being  excreted. 

II.  The  NON-NITROGENIZED  COMPOUNDS,  found  in  the  bodies  or  secretions 
of  animals,  are  not  numerous.  When  milk  is  dried,  two-fifths  of  its  solid 
contents  consist  of  a  peculiar  sugar,  called  saccharum  lactis,  and  composed 
of  C5  H4  044-HO.  It  crystallizes  in  four-sided  prisms,  and  has  a  sp.  gr 
of  1.543. 

It  also  contains  an  acid  called  lactic  (C6  H5  05),  common  in  all  the 
fluids  and  secretions  of  the  body,  and  united  in  them  with  either  potash 
soda,  ammonia,  lime,  or  magnesia. 

Fat-  consists  of  cells  held  together  by  areolar  tissue  and  vessels,  and  \s 
found  by  the  chemists  to  contain  glycerin,  stearic  add,  margaric  acid,  and 
elaic  acid,  all  of  which  are  destitute  of  nitrogen. 

The  solidity  of  the  fat  of  an  animal  depends  upon  the  proportion  of  the 
above  ingredients ;  thus,  when  stearic  acid  preponderates,  the  fat  is  solid, 
and  when  elaic,  flvid. 


HISTOLOGY. 


37 


OF     THE     XI  SSUES. 

The  solids  of  an  animal  body  have  been  divided  into  tissues,  any  one 
of  which  presents  the  same  characteristics,  no  matter  in  what  portion  of 
the  body  it  is  found.  The  tissues  may  be  further  divided  into  simple  and 
compound  tissues  ;  meaning  by  compound  those  which  consist  of  two  or 
more  simple  or  elementary  tissues  mixed  together  in  a  definite  and  regular 
manner.  As  an  instance  of  this  we  may  mention  fibro-cartilage,  which 
consists  of  a  net-work  of  white  fibrous  tissue,  having  its  meshes  or  inter- 
stices filled  up  by  a  cartilaginous  deposit. 

The  simplest  form  of  animal  organism  is 
the  nucleated  corpuscle  or  cell,  which  is  a 
little  vesicle  or  bag,  containing  a  fluid  in  its 
early  stage,  and  a  granular  body  called  a 
nucleus,  attached  to  some  portion  of  the  cell 
wall.  This  nucleus  occasionally  presents 
one  or  two  distinct  corpuscles  in  its  sub- 
stance, which  when  found  are  called  nucle- 
oli,  and  which  possibly  are  the  germs  of  new 
cells. 

Every  portion  of  the  animal  organism  is 

formed  by  these  cells,  and  as  the  body  is  undergoing  constant  repro- 
duction and  decay,  they  are  found  in  various  stages  of  development 
at  any  time  in  the  life  of  an  animal. 


DIVISION    OF    THE    TISSUES. 


The  animal  organism  may  be  divided  into  simple,  or  non-metamor- 
phosed forms,  and  compound,  or  metamorphosed  forms  of  animal  matter. 
They  are  presented  in  the  following  tabular  form : 

1.  SIMPLE  FORMS: — 


1. 


xr    i    t   i       n     $  1.  Formative,  producing  solids  (durable}. 
11S'  I  2.  Secreting,  producing  fluids  (evanescent). 


2.  Corpuscles, 


Of  the  blood, 

2.  Of  the  lymph, 

3.  Of  the  chyle. 


2.  COMPOUND  FORMS  : — 

Tissues  produced  by  the  metamorphosis  of  cells.     They  ara  divided 
into  simple  and  compound  tissues. 

Simple  Tissues : 

1.  Simple  membrane, 

2.  Pigmentary  membrane, 


1.  Epithelial  tissue, 
presenting  several 
varieties. 


3.  Tesselated  epithelium, 

4.  Cylindroid  epithelium, 


L 


5.  Ciliated  epithelium, 

6.  Aggregated  epithelium. 
2.  White  fibrous  tissue  (inelastic). 

3    Yellow  fibrous  tissue  (elastic). 

•  A  group  of  vegetable  cells.     1.  Nucleus.     2.  Nucleoli  in  nucleus. 


38  HISTOLOGY. 

4.  Cartilaginous  tissue. 

5.  Osseous  tissue. 

6.  Petrous  tissue. 

Compound  Tissues: 

,     TV/T        i      £u       **•          ^  !•  Striped  muscular  fibre, 

1.  Muscular  fibrous*  tissue,  3  „    TT    *  •      j  i     m 

'  £  2.  Unstnped  muscular  fibre. 

2.  Nerve-fibrous  tissue. 

Binary  Tissues,  formed  of  two  simple  tissues: 

1.  Areolar  tissue,  constituted  by  the  white  and  yellow  fibrous 

tissues  intermixed. 

2.  Fibro-cartilage,  constituted  by  cartilage  and  wrhite  fibrous 

tissue  intermixed. 

A  certain  difference  exists  between  the  simple  corpuscles  and  nucleated 
cells.  The  corpuscles  of  the  blood,  for  instance  (in  the  mammalia),  are 
destitute  of  a  nucleus,  and  are  persistent ;  whereas  a  nucleated  cell  is 
always  in  a  state  of  progression,  either  producing  a  fluid  or  undergoing  a 
transformation. 

The  1st  variety  of  epithelium  is  found  where  there  is  a  necessity  for 
transparency,  as  in  the  capsule  of  the  lens  and  the  posterior  layer  of  the 
cornea.  The  membrane  in  this  case  may  be  produced  by  the  develop- 
ment of  a  very  large  cell  and  the  collapse  of  its  walls,  so  as  to  cover  the 
whole  area,  thus  constituting  a  duplicate  lamina. 

The  2d  variety  is  formed  of  hexagonal  plates,  adhering  to  each  other 
and  containing  a  form  of  carbon  ;  it  is  found  in  the  eye,  in  the  lung,  and 
mixed  with  the  cuticle  and  hair  of  the  negro. 

The  3d  variety  constitutes  the  free  surface  of  many  membranes,  as  the 
skin,  the  mucous  and  serous ;  it  may  be  found  in  a  single  lamina,  forming 
a  pavement  of  nucleated  cells,  flattened  and  adhering  by  their  edges ;  or  it 
may  form  superimposed  laminae,  the  exterior  of  which  is  constantly  peeling 
off,  and  the  interior  as  constantly  reproducing  new  cells  to  keep  up  the 
covering.  This  is  the  case  in  the  cuticle,  and  in  the  mucous  membranes 
of  the  mouth,  ossophagus,  rectum,  &c. 

The  4th  variety  exists  in  mucous  membranes,  and  consists  of  conoidal 
nucleated  cells,  very  firmly  paved  together. 

The  5th  variety  differs  only  from  the  last  in  having  the  base  furnished 
vith  vibratile  cilia?,  which  diffuse  the  secretion,  moistening  the  surface  by 
tneir  constant  motion.  This  kind  of  epithelium  occurs  in  mucous  and 
serous  membranes,  where  the  surfaces  cannot  come  together  and  rub 
against  each  other,  as  in  the  ventricles  of  the  brain,  the  trachea,  &c. 

Nails,  hairs,  and  horny  excrescences,  are  manifestly  modifications  of 
epithelium,  and  are  hence  included  in  the  enumeration  as  constituting  tht 
sixth  variety  of  that  tissue. 

The  White  fibrous  tissue  exists  in  ligaments  and  tendons,  and  consti- 
tutes the  principal  part  of  the  derm  or  cutis  vera.  It  is  inelastic  and  in- 
extensible. 

The  Yellow  fibrous  tissue  is  found  in  the  ligamenta  fiava  of  the  spine, 
in  the  middle  coat  of  the  arterial  system,  and  in  the  skin,  mixed  with  the 
white  fibrous  element. 

The  Cartilaginous  tissue  constitutes  the  cartilage  of  the  ribs,  and  the 


HISTOLOGY.  39 

articular  coverings  for  the  ends  of  the  bones.  It  is  also  found  existing 
transitorily  in  the  process  of  osteo- genesis. 

The  Osseous  tissue  constitutes  the  skeleton,  and,  with  some  modification, 
the  ivory  of  the  teeth  or  dentine. 

The  Petrous  tissue  presents  the  extreme  of  departure  from  the  animal 
organization,  consisting  almost  entirely  of  crystals,  which  are  chiefly  com- 
posed of  phosphate  of  lime.  It  is  found  in  the  enamel  of  the  teeth,  in  the 
otoconites,  and  in  the  concretions  of  the  pineal  gland. 

The  Muscular  fibrous  tissue  constitutes  the  apparatus  of  motion,  and  is 
divided  into  two  distinct  varieties, — striped,  or  the  muscular  fibre  of  ani- 
mal life  ;  and  unstriped,  or  the  muscular  fibre  of  organic  life : — the  former 
acting  in  obedience  to  the  will,  and  the  latter  being  wholly  independent 
of  it. 

The  Nerve  fibre  is  the  conducting  portion  of  the  nervous  system,  and  is 
like  the  muscular  compound,  being  formed  of  two  distinct  substances,  the 
one  containing  and  the  other  contained. 

The  Binary  tissues  are  merely  the  intermixture  or  co-existence  of  two 
elementary  tissues,  the  proportions  of  which  vary  according  to  the  exigen- 
cies of  the  part  of  the  body  in  which  they  are  found. 

The  grey  or  vesicular  nervous  matter  consists  of  secreting  cells,  which 
disappear  and  are  reproduced. 

Adipose  tissue  consists  also  of  secreting  cells,  which  retain  their  con- 
tents under  certain  circumstances  for  a  great  length  of  time,  while  under 
others  they  rapidly  disappear. 

The  vascular,  mucous,  and  serous  tissues  of  older  writers,  consist  of 
aggregations  of  areolar,  muscular,  and  epithelial  tissues,  variously  modified. 

PROPERTIES    OF    THE    TISSUES. 

The  CHEMICAL  PROPERTIES  have  been  given  in  the  early  portion  of 
this  chapter. 

PHYSICAL    PROPERTIES    OF    THE    TISSUES. 

The  tissues,  like  other  forms  of  matter,  possess  certain  physical  proper- 
ties, such  as  colour,  consistency,  and  density,  which  it  is  necessary  to 
describe  under  their  respective  heads.  One  property,  however,  is  enjoyed 
by  every  tissue,  and  this  seems  to  play  a  most  important  part  in  the  main- 
tenance of  the  functions  of  life.  I  allude  to  the  transudation  of  the  solids 
by  the  fluids,  which  is  known  by  the  title  of  endosmosis  and  exosmosis, 
names  by  which  the  process  was  designated  by  Dutrochet,  its  discoverer. 
All  the  tissues  contain  a  certain  quantity  of  water,  and  in  some  cases  this 
amounts  to  four-fifths  of  their  weight,  as  may  be  proved  by  drying  them  ; 
and  this  water  is  essential,  not  only  to  their  vitality,  but  confers  upon  them 
their  organic  properties — pliability  and  elasticity.  As  the  tissues  imbibe 
water  in  certain  quantity,  it  becomes  a  subject  of  study  to  discover  the 
manner  by  which  the  quantity  may  be  increased.  It  is  well  understood 
how  pressure  from  without  would  produce  this  effect,  but  even  this  would 
be  aided  by  the  natural  tendency  to  imbibe  and  retain  an  additional  quan- 
tity of  water  under  favourable  circumstances,  which  is  strongly  exhibited 
by  the  softer  tissues.  Such  a  tissue  saturated  with  water  placed  in  contact 
with  another  tissue  or  a  fluid  having  a  higher  affinity  for  water  than  it  has, 
will  part  with  its  superabundance,  and  if  not  supplied  from  behind  will 


40  HISTOLOGY. 

even  part  with  a  portion  of  that  which  is  essential  to  its  normal  condition 
If,  however,  it  is  supplied  from  the  other  side,  it  will  continue  to  supply 
the  imbibing  fluid  and  receive  more  from  behind.  Thus  a  current  will  be 
established  from  the  water  on  one  side  of  the  tissue  to  the  fluid  having  a 
high  affinity  for  it  on  the  other ;  but  this  is  not  all :  for  the  fluid  alluded 
to,  not  content  with  absorbing  all  the  water  which  the  animal  tissue  sup- 
plies it  writh,  in  its  turn  transudes  the  tissue  to  get  at  and  mix  with  the 
water  on  the  other  side,  and  thus  a  counter-current  is  set  up  in  an  oppo- 
site direction,  which  is  slower,  however,  than  the  former  one.  These  are 
the  currents  which  are  termed  endosmotic  and  exosmotic,  and  which  con- 
tinue until  the  difference  between  the  two  liquids  ceases,  and  they  are 
equally  saturated  by  each  other. 

VITAL    PROPERTIES. 

The  most  prominent  vital  property  possessed  by  the  tissues  is  the  power 
of  assimilation,  or  of  appropriating  to  themselves  such  of  the  organizable 
substances  presented  to  them  as  may  suit  their  purposes.  This  power  is 
supposed  to  be  partly  due  to  chemical  affinity,  and  partly  to  vital  affinity. 
It  is  most  probable,  however,  that  future  researches  will  prove  that  the 
power  of  assimilating  is  subject  to  the  ordinary  chemical  laws,  but  under 
modifying  circumstances,  which  can  only  exist  in  a  living  body  or  tissue. 

To  this  may  be  added  the  power  of  reproducing,  in  its  appropriate 
place,  a  new  portion  of  a  tissue,  when  injured  or  destroyed. 

Another  property  which  is  essentially  vital  is  contractility — a  phenome- 
non which  is  made  manifest  by  the  visible  shrinking  or  contraction  of  a 
living  tissue  when  irritated,  either  by  mechanical  or  chemical  stimuli. 
The  muscular  tissue  exhibits  this  property  in  the  highest  degree.  This 
contractility  must  be  distinguished  from  the  permanent  contraction  or 
crispation  which  a  part  suffers  when  exposed  to  a  high  temperature. 

A  third  vital  property  is  sensibility,  which,  however,  requires  that  the 
tissues  shall  be  united  so  as  to  form  a  continuous  line  from  the  part  mani- 
festing it  to  the  brain.  This  property  is  enjoyed  in  very  different  degrees 
by  the  different  tissues,  and  constitutes  an  important  distinction  between 
them,  depending  upon  the  presence  and  number  of  nerve-fibres  mixed 
with  the  tissue. 

DEVELOPMENT    OF    THE    TISSUES. 

The  tissues,  however  diversified  in  form,  are  all  developed  in  the  fol- 
lowing manner: 

A  nucleated  cell  attracts  from  the  blastema  in  which  it  is  formed,  or 
from  the  capillary  vessels  contiguous  to  it,  certain  elements  which  combine 
in  its  interior,  and  either  form  a  portion  of  the  animal  body, — in  which 
case  the  remains  of  the  cell,  and  particularly  its  nucleus,  continue  to  exist 
in  the  part,  and  can  be  made  evident  by  chemical  agents  under  the 
microscope, — or  they  become  filled  with  a  fluid,  and  bursting  when  ripe, 
and  mixing  and  flowing  along  with  their  former  contents,  are  discharged 
into  a  tube  or  duct,  and  constitute  a  secretion  or  a  secreted  fluid.  The  only 
difference  between  these  two  kinds  of  cell,  which  we  designate  by  the  terms 
formative  and  secreting,  is  that  the  former  secrete  a  solid  or  semi-solid, 
which  remains  in  the  body  with  the  debris  of  the  cell  for  an  appreciable 
period  of  time,  whilst  the  latter  secrete  a  fluid  which  escapes  from  the 


HISTOLOGY.  41 

body  with  the  remains  of  the  cell  which  gave  it  birth.  Each  of  these 
little  bodies  may  be  compared  to  a  laboratory,  which  receives  from  the 
surrounding  matter  the  elements  which  it  requires,  and  combines  them  so 
as  to  produce  a  desired  result. 

The  various  modifications  and  aggregations  of  these  cells  constitute  the 
varied  forms  of  animal  and  vegetable  tissues. 

DEVELOPMENT     OF     CELLS. 

A  cell  originates  in  a  mass  of  soft  or  liquid  matter,  which  is  organizable 
or  capable  of  being  organized.  In  other  words,  a  liquid  formed  of  a  com- 
bination of  elements  fitted  to  produce  an  organized  structure.  This  sub- 
stance is  called  "blastema."  As  an  example,  we  may  take  the  liquor 
sanguinis  or  the  blood,  excluding  its  globules,  which  in  a  fully  formed 
animal  is  a  universally  diffused  blastema. 

A  minute  point  (see  Fig.  2)  arises  in  this  blastema,  which  increases  in 

size ;  a  transparent  wall  is  seen  to 
spring  up  like  a  watch-glass  from  one 
side  of  the  granule,  which  swells .  up 
more  and  more  until  the  granule  is  seen 
to  exist  in,  and  adhere  to  the  side  of  the 
cell  wall.  When  thus  formed,  we  have 
the  cell  wall  with  its  fluid  contents,  and  the  granule  or  nucleus,  which 
may  by  this  time  have  developed  several  new  granules  or  nucleoli  in  its 
interior. 

MULTIPLICATION    OF    CELLS. 

Cells  are  multiplied  in  several  modes : 

1st.  By  repetition,  i.  e.,  of  the  development  from  a  blastema,  as  ex- 
plained. 

2d.  By  the  development  of  new  nuclei  and  cells  within  the  parent  cell 
wall  (see  fig.  3). 

Fig.  3.t 


3d.  By  the  development  of  new  cells  from  the  parietes  of  pre-existing 
ones,,  This  is  shown  in  fig.  4. 

TRANSFORMATION     OF    CELLS. 

1st.  Cells  may  lose  their  fluid  contents,  and  their  walls  collapsing  until 
they  come  in  cojitact  and  adhere,  they  form  simple,  membranous,  and 
transparent  discs. 

*  Development  of  cell  from  blastema.     On  the  left  is  seen  the  corpuscle  which  be 
comes  the  nucleus ;  on  the  right  the  complete  nucleated  cell, 
j-  Development  of  new  cells  within  the  parent  cell, 
i  Development  of  new  cells  from  the  outer  wall  of  pre-existing  cells. 

4* 


42 


HISTOLOGY. 


2d.  Cells  may  elongate  so  as  to  form  tubes  or  solid  rods ;  in  the  former 
case  they  adhere  by  their  ends  to  neighbouring  cells,  and  their  cavities 
mutually  open  into  each  other,  thus  forming  a  vessel :  in  the  latter  the 

fluid  content  is  lost,  and  a  rod  or 
fibre  is  the  result.  Curious  forms 
are  produced  by  a  modification  of 
the  same  law,  as  exemplified  in 


^V 


fig.  5. 


,A*  .  Ay        3d.   Solid  deposits  may  occur 

ftjT      ^^        \  S*\   **  witnin  tne  ce^  wallj  obliterating  its 

v/    V   }  l~  /  V  cavity- 

•*  4th.  The  same  thing  may  occu, 

in  the  blastema,  exterior  to  the  cell 
walls,  and  thus  a  solid  will  result. 
Examples  of  the  third  and  fourth 

kind  occur  in  the  formation  of  cartilage,  as  is  illustrated  in  the  accompa- 
nying cuts. 


Fig.  6.f 


Fig.  7.f 


Fig.  s.f 


Fig.  9.* 


Fig.  10.§ 


5th.  A  curious  modification  of  development 
occurs  in  the  feathers  of  birds,  where  a  nucleated 
cell  elongates  and  becomes  filled  with  fibres ;  the 
i  cell  wall  is  rubbed  off  by  attrition,  and  the  fibres 
are  thus  uncovered  and  exposed.  See  fig.  10, 
a,  6,  c. 

•  Finally,  it  is  believed  by  some  that  the  blastema 
may  form  a  simple  membrane  or  fibre  without  the 
intervention  of  a  cell,  although  this  is  by  no  means 
proved. 


*  Curious  forms  of  cell  transformation  usually  found  in  abnormal  deposits. 

j-  Development  of  cartilage. 

t  Deposit  in  layers  of  lignin  in  the  interior  of  vegetable  cells. 

§  Mode  of  formation  of  the  feathers  of  a  bird  in  the  interior  of  a  nucleated  cell. 


CLASSES    OF    BONE.  43 

CHAPTER  II. 

OSTEOLOGY. 

THE  bones  are  the  organs  of  support  to  the  animal  frame ;  thty  ^ive 
firmness  and  strength  to  the  entire  fabric,  afford  points  of  connection  to 
the  numerous  muscles,  and  bestow  individual  character  upon  the  body. 
In  the  limbs  they  are  hollow  cylinders,  admirably  calculated  by  their  con- 
formation and  structure  to  resist  violence  and  support  weight.  In  the 
trunk  and  head,  they  are  flattened  and  arched,  to  protect  cavities  and 
provide  an  extensive  surface  for  attachment.  In  some  situations  they 
present  projections  of  variable  length,  which  serve  as  levers  ;  and  in  others 
are  grooved  into  smooth  surfaces,  which  act  as  pulleys  for  the  passage  of 
tendons.  Moreover,  besides  supplying  strength  and  solidity,  they  are 
equally  adapted,  by  their  numerous  divisions  and  mutual  apposition,  to 
fulfil  every  movement  which  may  tend  to  the  preservation  of  the  creature, 
or  be  conducive  to  his  welfare. 

According  to  the  latest  analysis  by  Berzelius,  bone  is  composed  of  about 
one-third  of  animal  substance,  which  is  almost  completely  reducible  to 
gelatine  by  boiling,  and  of  two-thirds  of  earthy  and  alkaline  salts.  The 
special  constituents  of  bone  are  present  in  the  following  proportions : — 

Cartilage 32-17  parts. 

Blood-vessels 1-13 

Phosphate  of  lime 51-04 

Carbonate  of  lime 11-30 

Fluate  of  lime 2-00 

Phosphate  of  magnesia 1-16 

Soda,  chloride  of  sodium 1-20 


100-00 

Bones  are  divisible  into  three  classes: — Long^flat^  and  irregular. 
The  Long  bones  are  found  principally  in  the  limbs,  and  consist  of  a 
shaft  and  two  extremities.  The  shaft  is  cylindrical  or  prismoid  in  form, 
dense  and  hard  in  texture,  and  hollowed  in  the  interior  into  a  medullary 
canal.  The  extremities  are  broad  and  expanded,  to  articulate  with  ad- 
joining bones  ;  and  cellular  or  cancellous  in  internal  structure.  Upon  the 
exterior  of  the  bone  are  processes  and  rough  surfaces  for  the  attachment 
of  muscles,  and  foramina  for  the  transmission  of  vessels  and  nerves.  The 
character  of  long  bones  is,  therefore,  their  general  type  of  structure  and 
their  divisibility  into  a  central  portion  and  extremities,  and  not  so  much 
their  length  ;  for  there  are  some  long  bones,  as  the  second  phalanges  of 
the  toes,  which  are  less  than  a  quarter  of  an  inch  in  length,  and  almost 
equal,  and  in  some  instances  exceed,  in  breadth  their  longitudinal  axis. 
The  long  bones  are,  the  clavicle,  humerus,  radius  and  ulna,  femur,  tibia 
and  fibula,  metacarpal  bones,  metatarsal,  phalanges,  and  ribs. 

Flat  bones  are  composed  of  two  layers  of  dense  bone  with  an  interme- 
diate cellular  structure,  and  are  divisible  into  surfaces,  borders,  angles,  and 
processes.  They  are  adapted  to  inclose  cavities ;  have  processes  upon 
their  surface  for  the  attachment  of  muscles ;  and  are  perforated  by  foramina, 
for  the  passage  of  nutrient  vessels  to  their  cells,  and  for  the  transmission 


44 


STRUCTURE    OF    BONE. 


of  vessels  and  nerves.  They  articulate  with  long  bones  by  means  of  smooth 
surfaces  plated  with  cartilage,  and  with  each  other  either  by  fibrous  tissue, 
as  at  the  symphysis  pubis ;  or  by  suture,  as  in  the  bones  of  the  skull.  The 
two  condensed  layers  of  the  bones  of  the  skull  are  named  tables ;  and  the 
intermediate  cellular  structure,  diploe.  The  flat  bones  are  the  occipital, 
parietal,  frontal,  nasal,  lachrymal,  vomer,  sternum,  scapulse,  and  ossa 
innominata. 

The  Irregular  bones  include  all  that  remain  after  the  long  and  the  flat 
bones  have  been  selected.  They  are  essentially  irregular  in  their  form,  in 
some  parts  flat,  in  others  short  and  thick.  In  preceding  editions  of  this 
work  the  short  and  thick  bones  were  made  a  separate  class,  under  the 
name  of  short  bones.  This  subdivision  has  been  found  to  be  disadvan- 
tageous, besides  being  arbitrary,  and  is,  therefore,  now  omitted.  Irregular 
bones  are  constructed  on  the  same  general  principles  with  other  bones ; 
they  have  an  exterior  dense,  and  an  interior  more  or  less  cellular.  The 
bones  of  this  class  are,  the  temporal,  sphenoid,  ethmoid,  superior  maxil- 
lary, inferior  maxillary,  palate,  inferior  turbinated,  hyoid,  vertebrae,  sacrum, 
coccyx,  carpal  and  tarsal  bones,  and  sesamoid  bones,  including  the  patelke. 

Structure  of  Bone. — Bone  is  a  dense,  compact,  and  homogeneous  sub- 
stance (basis  substance)  filled  with  minute  cells  (corpuscles  of  Purkinje), 
which  are  scattered  numerously  through  its  structure.  The  basis  substance 
of  bone  is  subfibrous  and  obscurely  lamellated,  the  lamella?  being  concentric 
in  long  and  parallel  in  flat  bones;  it  is  traversed  in  all  directions,  but  es- 
pecially in  the  longitudinal  axis,  by  branching  and  inosculating  canals 


Fig.  11* 


(Haversian  canals),  which  give 
passage  to  vessels  and  nerves, 
and  in  certain  situations  the  la- 
mellaa  separate  from  each  other, 
and  leave  between  them  areolar 
spaces  (cancelli)  of  various  mag- 
nitude. The  lamellae  have  an 
average  diameter  of  %-$$-$  of  an 
inch,  and,  besides  constituting  the 
general  structure  of  the  basis  sub- 
stance, are  collected  concentrically 
around  the  Haversian  canals,  and 
form  boundaries  to  those  canals  of 
about  2J3  of  an  inch  in  thickness. 
The  number  of  lamella  surround- 
ing each  Haversian  canal  is  com- 
monly ten  or  fifteen,  and  the  di- 
ameters of  the  canals  have  a  me- 
dium average  of  g^  of  an  inch.  The  cancelli  of  bone,  like  its  compact 
substbjice,  have  walls  which  are  composed  of  lamellae ;  and,  such  is  the 

*  M:nnte  structure  of  bone,  drawn  with  the  microscope  from  nature,  by  Bagg.  Mag- 
nified 300  diameters.  1.  One  of  the  Haversian  canals  surrounded  by  its  concentric 
lamellae.  The  corpuscles  are  seen  between  the  lamellae;  but  the  calcigerous  tubuli  are 
omitted.  2.  An  Haversian  canal  with  its  concentric  lamellae,  Purkinjean  corpuscles, 
and  tubuli.  3.  The  area  of  one  of  the  canals.  4,  4.  Direction  of  the  lamellae  of  the 
great  medullary  canal.  Between  the  lamellae  at  the  upper  part  of  the  figure,  several 
very  long  corpuscles  with  their  tubuli  are  seen.  In  the  lower  part  of  the  figure,  the  out- 
lines of  three  other  canals  are  given,  in  order  to  show  their  form  and  mode  of  arrange- 
ment in  the  entire  lone. 


DEVELOPMENT    OF    BONE.  45 

similarity  in  structure  of  the  parts  of  a  bone,  that  the  entire  bone  may  be 
compared  to  anHaversian  canal  of  which  the  medullary  cavity  is  the  mag- 
nified channel ;  and  the  Haversian  canals  may  be  likened  to  elongated  and 
ramified  cancelli.  The  Haversian  canals  are  smallest  near  the  surface 
of  a  bone,  and  largest  near  its  centre,  where  they  gradually  merge  into 
cancelli ;  by  the  frequent  communications  of  their  branches  they  form  a 
coarse  network  in  the  basis  substance. 


The  cells  of  bone,  or  corpuscles  of  Purkinje,  are  thickly  disseminate*! 
through  the  basis  substance ;  they  are  irregular  in  size  and  form,  give 
off  numerous  minute  branching  tubuli,  which  radiate  from  all  parts  of 
their  circumference,  and  in  the  dried  state  of  the  bone  contain  merely 
the  remains  of  membranous  cells  and  some  calcareous  salts. f  In  the 
living  bone,  the  cells  and  their  tubuli  are  probably  filled  with  a  nutritive 
fluid  holding  calcareous  salts  in  solution.  The  form  of  the  cells  is  oval 
or  round,  and  more  or  less  flattened,  their  long  diameter  corresponds 
with  the  long  axis  of  the  bone,  and  their  tubuli  cross  the  direction  of  the 
lamellae,  and  constitute  a  very  delicate  network  in  the  basis  substance, 
by  communicating  with  each  other,  and  with  the  tubuli  of  neighbouring 
cells.  The  tubuli  of  the  cells  nearest  the  Haversian  canals  terminate 
upon  the  internal  surface  of  those  cavities.  The  size  of  the  cells  varies 
in  extreme  measurement  from  g^1^  to  g^5  of  an  inch  in  their  long  diame- 
ter, an  ordinary  average  being  yo'au ;  the  breadth  of  the  oval  cells  is 
about  one-half  or  one-third  their  length,  and  their  thickness  one-half 
their  breadth.  They  are  situated  between  the  lamellae,  to  which  circum- 
stance they  owe  their  compressed  form. 

*  The  above  cut,  which  I  have  introduced  to  supply  the  manifest  deficiency  of  Mr. 
Wilson's  representation,  is  from  a  section  of  a  human  femur,  about  its  middle,  and  ex- 
hibits the  erratic  course  of  the  Haversian  canals,  and  their  relations  to  each  other,  and 
at  the  same  time  the  general  laminated  condition  of  a  long  bone.  This  laminated  con- 
dition is  well  shown  by  polarized  light,  which  causes  the  corpuscles  to  disappear,  and 
the  lamince  to  come  out  boldly. — G. 

•f-Miiller  and  Henle  conceived  that  the  bone  cells  and  tubuli  were  the  principal  sea1 
of  the  calcareous  matter.  Hence  they  have  been  named  caldgerous  cells  and  tnbuli. 


46  DEVELOPMENT    OF   BO\E. 

In  the  fresh  state,  bones  are  invested  by  a  dense  fibrous  membrane, 
the  periosteum,  which  covers  every  part  of  their  surface,  with  the  excep- 
tion of  the  articular  extremities,  the  latter  being  coated  by  a  thin  layer 
of  cartilage.  The  periosteum  of  the  bones  of  the  skull  is  termed  peri- 
cranium ;  and  the  analogous  membrane  of  external  cartilages,  perichon- 
drium.  Lining  the  interior  of  the  medullary  canal  of  long  bones,  the 
Haversian  canals,  the  cells  of  the  cancelli,  and  the  cells  of  short,  flat, 
and  irregular  bones,  is  the  medullary  membrane,  which  acts  as  an  internal 
periosteum.  It  is  through  the  medium  of  the  vessels  ramifying  in  these 
membranes  that  the  changes  required  by  nutrition  occur  in  bones,  and 
the  secretion  of  medulla  into  their  interior  is  effected.  The  medullary 
canal,  Haversian  canals,  and  cells  of  long  bones,  and  the  cells  of  other 
bones,  are  filled  with  a  yellowish  oily  substance,  the  medulla,  which  is 
contained  in  a  loose  areolar  tissue  formed  by  the  medullary  membrane. 

Development  of  Bone. — To  explain  the  development  of  bone  it  is  ne- 
cessary to  inform  the  student,  that  all  organized  bodies,  whether  belong- 
ing to  the  vegetable  or  the  animal  kingdom,  are  developed  primordially 
from  minute  vesicles.  These  vesicles,  or,  as  they  are  commonly  termed, 
cells,  are  composed  of  a  thin  membrane  containing  a  fluid  or  granular 
matter,  and  a  small  rounded  mass,  the  nucleus,  around  which  the  cell  was 
originally  formed.  Moreover,  the  nucleus  generally  contains  one  or 
more  small  round  granules,  the  nucleolus  or  nucleoli.  From  cells  having 
this  structure  all  the  tissues  of  the  body  are  elaborated ;  the  ovum  itself 
originally  presented  this  simple  form,  and  the  embryo  at  an  early  period 
is  wholly  composed  of  such  nucleated  cells.  In  their  relation  to  each 
other,  cells  may  be  isolated  and  independent,  as  is  exemplified  in  the 
corpuscles  of  the  blood,  chyle,  and  lymph ;  secondly,  they  may  cohere 
by  their  surfaces  and  borders,  as  in  the  epiderma  and  epithelium;  thirdly, 
they  may  be  connected  by  an  intermediate  substance,  which  is  then 
termed  intercellular,  as  in  cartilage  and  bone ;  and  fourthly,  they  may 
unite  with  each  other  in  rows,  and  upon  the  removal,  by  liquefaction,  of 
the  adherent  surfaces,  be  converted  into  hollow  tubuli.  In  the  latter  mode 
capillary  vessels  are  formed,  as  also  are  the  tubuli  of  nerve  and  muscular 
fibre.  One  of  the  properties  of  cells  may  also  be  adverted  to  in  this  place ; 
it  is  that  of  reproducing  similar  cells  in  their  interior.  In  this  case  the 
nucleoli  become  the  nuclei  of  the  secondary  cells,  and  as  the  latter  increase 
in  size,  the  membrane  of  the  primary  or  parent  cell  is  lost. 

Bone,  in  its  earliest  stage,  is  composed  of  an  assemblage  of  these  mi- 
nute cells,  which  are  soft  and  transparent,  and  are  disposed  wyithin  the 
embryo  in  the  site  of  the  future  skeleton.  From  the  resemblance  which 
the  soft  tissue  bears  to  jelly,  this  has  been  termed  the  gelatinous  stage  of 
osteo-genesis.  As  development  advances,  the  cells,  heretofore  loosely 
collected  together,  become  separated  by  the  interposition  of  a  transparent 
intercellular  substance,  which  is  at  first  fluid,  but  gradually  becomes  hard 
and  condensed.  The  cartilaginous  stage  of  osteo-genesis  is  now  esta- 
blished, and  cartilage  is  shown  to  consist  of  a  transparent  matrix,  having 
minute  cells  disseminated  at  pretty  equal  distances,  and  without  order, 
through  its  structure.  Coincident  with  the  formation  of  cartilage  is  the 
development  of  vascular  canals  in  its  substance,  the  canals  being  formed 
by  the  union  of  the  cells  in  rows,  and  the  subsequent  liquefaction  of  the 
adhering  surfaces.  The  change  which  next  ensues  in  the  concentration 
of  the  vascular  canals  towards  some  one  point ;  for  example,  the  centre 


DEVELOPMENT    OF    BONE. 


47 


0 


of  the  shaft  in  a  long,  or  the  mid-point  of  a  flat  bone,  and  here  die  punctum 
ossificationis,  or  centre  of  ossification,  is  established.  What  determines 
the  vascular  concentration  now  alluded  to,  is  a  question  not  easily  solved, 
but  that  it  takes  place  is  certain,  and  the  vascular  punctum  is  the  most 
easily  demonstrable  of  all  the  phenomena  of  ossification. 

During  the  formation  of  , 

the  punctum  ossificationis, 

changes  begin  to  be  appa-  B 

rent  in  the  cartilage  cells.  •*•  ^  ^  ^  ^<g  ^  $9     & 

Originally  they  are  simple 
nucleated  cells  (§^0^  to 
Woo  °f  an  mch  m  diame- 
ter), having  a  rounded 
form.  As  growth  pro- 
ceeds, they  become  elon- 
gated in  their  figure,  and  v  ®$ 
it  is  then  perceived  that 

each  cell  contains  two  and  often  three  nucleoli,  around  which  smaller  cells 
are  in  progress  of  formation. 

Tt-  •         ,1  Fif    14  + 

It  we  examine  them  nearer 
to  the  punctum  ossificationis, 
we  find  that  the  young  or 
secondary   cells   have   each 
attained  the  size  of  the  pa- 
rent cell  (Woo  °f  an  inch), 
the  membrane  of  the  parent 
cell    has   disappeared,    and 
the  young  cells  are  separated 
to  a  short  distance  by  freshly 
effused  intercellular  substance. 
a  more   remarkable 
change  has  ensued, 
the  energy  of  cellule 
reproduction        has 
augmented         with 
proximity  to  the  os- 
sifying   point,    and 
each  cell  in  place  of 
producingtwo,  gives 
birth  to  four,  five,  or 
six     young      cells, 
which    rapidly    de- 

*  Figures  illustrative  of  the  development  of  bone;  they  are  magnified  155  times, 
and  drawn  with  the  camera  lucida.  A.  A  portion  of  cartilage  the  farthest  removed  from 
the  seat  of  ossification,  showing  simple  nucleated  cells,  having  an  ordinary  size  of  yBV-T 
of  an  inch,  long  diameter.  B.  The  same  cartilage,  nearer  the  seat  of  ossification ;  each 
simple  cell  has  produced  two,  which  are  a  little  larger  than  the  cells  in  figure  A. 

j-  The  same  cartilage,  still  nearer  the  seat  of  ossification ;  each  single  cell  of  B  has 
given  birth  to  four,  five,  or  six  cells,  which  form  clusters.  These  clusters  become 
larger  towards  the  right  of  the  figure,  and  their  cells  more  numerous  and  larger,  -JV1> 
of  an  inch,  long  diameter. 

t  The  same  cartilage,  at  the  seat  of  ossification;  the  clusters  of  cells  are  arrange'!  in 
columns ;  the  intercellular  spaces  between  the  columns  being  5.,^ff  of  an  incb  ir 


Nearer  still  to  the  punctum  ossifieationig 

Fig.  154 


48  DEVELOPMENT    OF   BONE. 

stroy  the  parent  membrane  and  attain  a  greater  size  (y^ou  of  an  inch)  than 
the  parent  cell,  each  cell  being,  as  in  the  previous  case,  separated  to  a 
slight  extent  from  its  neighbour  by  intercellular  substance.  By  one  other 
repetition  of  the  same  process,  each  cell  producing  four,  or  five,  or  six 
young  cells,  a  cluster  is  formed,  containing  from  thirty  to  fifty  cells.  These 
clusters  lie  in  immediate  relation  with  the  punctum  ossificationis  ;  they  are 
oval  in  figure  (about  ^  in  length  by  g^  in  breadth),  and  placed  in  the 
direction  of  the  longitudinal  axis  of  the  bone.  The  cells  composing  the 
cluster  lie  transversely  with  regard  to  its  axis.  In  the  first  instance  they 
are  closely  compressed,  but  by  degrees  are  parted  by'athin  layer  of  inter- 
cellular substance,  and  each  cluster  is  separated  from  neighbouring  clus- 
ters by  a  broader  layer  (^2*5-^  of  an  inch)  of  intercellular  substance.  Such 
are  the  changes  which  occur  in  cartilage  preparatory  to  the  formation  of 
bone. 

Ossification  is  accomplished  by  the  formation  of  very  fine  and  delicate 
fibres  within  the  intercellular  substance :  this  process  commences  at  the 
punctum  ossificationis,  and  extends  from  that  point  through  every  part  of 
the  bone,  in  a  longitudinal  direction  in  long,  and  in  a  radiated  manner  in 
flat  bones.  Starting  from  the  punctum  ossificationis,  the  fibres  embrace 
each  cluster  of  cells,  and  then  send  branches  between  the  individual  cells 
of  each  group.  In  this  manner  the  network,  characteristic  of  bone,  is 
formed,  while  the  cells  by  their  conjunction  constitute  the  permanent 
areolas  and  Haversian  canals.  With  a  high  magnifying  power,  the  deli- 
cate ossific  fibres  here  alluded  to  are  seen  themselves  to  be  composed  of 
minute  cells  having  an  elliptical  form  and  central  nuclei.  These  cells 
attract  into  their  interior  the  calcareous  salts  of  the  blood,  and  their  nuclei 
become  developed,  as  I  believe,  into  the  future  corpuscles  of  Purkinje. 
It  is  possible  also  that  some  of  the  cartilage  cells  become  corpuscles  of 
Purkinje  in  the  fully  developed  bone. 

During  the  progress  of  the  phenomena  above  described,  the  contents 
of  the  cells  undergo  certain  changes.  At  first,  their  contents  are  transpa- 
rent, then  they  become  granular,  and  still  later  opaque,  from  the  presence 
of  amorphous  matter  mingled  with  nuclei,  nucleoli,  and  the  remains  of 
secondary  cells.  In  the  latter  state  they  also  contain  an  abundance  of 
minute  oil-globules.  These  latter  increase  in  size  as  the  ossific  changes 
advance,  and  in  the  newly  formed  osseous  areolas  they  are  very  numerous 
and  have  attained  the  ordinary  size  of  adipose  cells. 

Cartilaginification  is  complete  in  the  human  embryo  at  about  the  sixth 
week ;  and  the  first  point  of  ossification  is  observed  in  the  clavicle  at 
about  the  seventh  week.  Ossification  commences  at  the  centre,  and 
thence  proceeds  towards  the  surface  ;  in  flat  bones  the  osseous  tissue  ra- 
diates between  two  membranes  from  a  central  point  towards  the  periphery, 
in  short  bones  from  a  centre  towards  the  circumference,  and  in  long  bones 
from  a  central  portion,  diaphysis,  towards  a  secondary  centre,  epiphysis, 
situated  at  each  extremity.  Large  processes,  as  the  trochanters,  are  pro- 
vided with  a  distinct  centre  of  development,  which  is  named  apophysis. 

breadth.  To  the  right  of  the  figure  osseous  fibres  are  seen  occupying  the  intercellulai 
spaces,  at  first  bounding  the  clusters  laterally,  then  splitting  them  longitudinally,  and 
encircling  each  separate  cell.  The  greater  opacity  of  the  right-hand  border  is  due  to  a 
threefold  cause,  the  increase  of  osseous  fibres,  the  opacity  of  the  contents  of  the  cells, 
nnd  the  multiplication  of  oil-globules.  In  the  lower  part  of  the  figur?  some  attemp 
has  been  made  to  show  the  texture  of  the  cells. 


DEVELOPMENT    OF   BONE.  4il 

The  growth  of  bone  in  length  takes  place  at  the  extremity  of  the  dia- 
physis,  and  in  bulk  by  fresh  deposition  on  the  surface  ;  while  the  medul- 
lary canal  is  formed  and  increased  by  absorption  from  within. 

The  period  of  ossification  is  different  in  different  bones ;  the  order  of 
succession  may  be  thus  arranged  : — 

During  the  fifth  week,  ossification  commences  in  the  clavicle,  lower 
jaw,  and  upper  jaw. 

During  the  sixth  week,  in  the  femur,  humerus,  tibia,  radius,  and  ulna. 

During  the  seventh  and  eighth  weeks,  in  the  fibula,  frontal,  occipital, 
sphenoid,  ribs,  parietal,  temporal,  nasal,  vomer,  palate,  vertebrae,  first 
three  pieces  of  sacrum,  malar,  metacarpus,  metatarsus,  third  phalanges  of 
the  hands  and  feet,  and  ilium. 

During  the  third  month,  in  the  first  and  second  phalanges  of  the  hands 
and  feet,  lachrymal  bone,  and  ischium. 

During  the  fifth  month,  in  the  mastoid  portion  of  the  temporal,  ethmoid, 
inferior  turbinated,  sternum,  os  pubis,  and  last  two  pieces  of  sacrum. 

During  the  sixth  month,  in  the  body  and  odontoid  process  of  the  axis, 
and  in  the  calcaneus. 

During  the  seventh  month,  in  the  astragalus. 

During  the  tenth  month,  in  the  cuboid  bone  and  os  hyoides. 

During  the  first  year,  in  the  coracoid  process  of  the  scapula;  first  piece 
of  the  coccyx,  inferior  turbinated  bone,  last  piece  of  the  sternum,  anterior 
arch  of  the  atlas,  os  magnum,  os  unciforme,  and  external  cuneiform  bone. 

During  the  third  year,  in  the  cuneiform  of  the  carpus,  internal  cuneiform 
of  the  tarsus,  and  patella. 

During  the  fourth  year,  in  the  middle  cuneiform  and  scaphoid  of  the 
tarsus. 

During  the  fifth  year,  in  the  trapezium  and  os  semilunare. 

During  the  seventh  year,  in  the  second  piece  of  the  coccyx. 

During  the  eighth  year,  in  the  scaphoid  of  the  carpus. 

During  the  ninth  year,  in  the  os  trapezoides. 

During  the  twelfth  year,  in  the  os  fisiforme  and  third  piece  of  the  coccyx. 

During  the  eighteenth  year,  in  the  fourth  piece  of  the  coccyx. 

The  ossicula  auditus  are  the  only  bones  completely  ossified  at  birth;  the 
vertebrae  are  not  completed  until  the  five-and-twentieth  year. 

The  entire  osseous  framework  of  the  body  constitutes  the  skeleton,  which 
in  the  adult  man  is  composed  of  two  hundred  and  forty-six  distinct  bones. 
They  may  be  thus  arranged : — 

Head 8 

Ossicula  auditus 6 

Face 14 

Teeth 32 

Vertebial  column,  including  sacrum  and  coccyx  26 

Os  hyoides,  sternum,  and  ribs 26 

Upper  extremities 64 

Lower  extremities 62 

Sesamoid  bones                                    ....  8 


246 

The  skeleton  is  divisible  into  :  1.  The  vertebral  column,  or  central  axis 
2.  The  head  and  face,  or  superior  development  of  the  central  axis.     3 
5  D 


50  VERTEBRAL    COLUMN. 

The  hyoid  arch.     4.  The  thoracic  arch  and  upper  extremities.     5.  The 
pelvic  arch  and  lower  extremities. 

VERTEBRAL    COLUMN. 

The  vertebral  column  is  the  first  and  only  rudiment  of  internal  skeleton 
in  the  lower  Vertebrata,  and  constitutes  the  type  of  that  great  division  of 
the  animal  kingdom.  It  is  also  the  first  developed  portion  of  the  skeleton 
in  man,  and  the  centre  around  which  all  the  other  parts  are  produced. 
In  its  earliest  formation  it  is  a  simple  cartilaginous  cylinder,  surrounding 
and  protecting  the  primitive  trace  of  the  nervous  system ;  but,  as  it  advances 
in  growth  and  organisation,  it  becomes  divided  into  distinct  pieces,  which 
constitute  vertebra:. 

The  vertebrae  are  divided  into  true  and  false.  The  true  vertebras  are 
twenty-four  in  number,  and  are  classified,  according  to  the  three  regions 
of  the  trunk  which  they  occupy,  into  cervical,  dorsal,  and  lumbar.  The 
false  vertebra  consist  of  nine  pieces  united  into  two  bones,  the  sacrum  and 
coccyx  The  arrangement  of  the  vertebra;  may  be  better  comprehended 
by  means  of  the  accompanying  table : — 

(          7  Cervical, 

True  vertebras  24      <        12  Dorsal, 
(          5  Lumbar. 

•n  i  *  v      n      ^          5  Sacrum, 

False  vertebrae  9      <          A  0 

\          4  Coccyx. 

Characters  of  a  Vertebra. — A  vertebra  consists  of  a  body,  two  laminae, 
a  spinous  process,  two  transverse  processes,  and  four  articular  processes. 
The  body  is  the  solid  part  of  the  vertebra ;  and,  by  its  articulation  with 
adjoining  vertebras,  gives  strength  and  support  to  the  trunk.  It  is  flattened 
above  and  below,  convex  in  front,  and  slightly  concave  behind.  Its  an- 
terior surface  is  constricted  around  the  middle,  and  pierced  by  a  number 
of  small  openings  which  give  passage  to  nutritious  vessels.  Upon  its  pos- 
terior surface  is  a  single  irregular  opening,  or  several,  for  the  exit  of  the 
venae  basis  vertebrae. 

The  lamina  commence  upon  the  sides  of  the  posterior  part  of  the  body 
of  the  vertebra  by  two  pedicles;  they  then  expand;  and,  arching  back- 
wards, enclose  a  foramen  which  serves  for  the  protection  of  the  spinal 
cord.  The  upper  and  lower  borders  of  the  laminae  are  rough  for  the  at- 
tachment of  the  ligamenta  subflava.  The  concavities  above  and  below  the 
pedicles  are  the  intervertebral  notches.  The  spinous  process  stands  back- 
wards from  the  angle  of  union  of  the  laminae  of  the  vertebra.  It  is  the 
succession  of  these  projecting  processes  along  the  middle  line  of  the  back, 
that  has  giv^.i  rise  tc  the  common  designation  of  the  vertebral  column,  the 
spine.  The  use  of  the  spinous  process  is  for  the  attachment  of  muscles. 
The  transverse  processes  project  one  at  each  side  from  the  laminae  of  the 
vertebra;  they  are  intended  for  the  attachment  of  the  muscles.  The  arti- 
cular processes,  four  in  number,  stand  upwards  and  downwards  from  the 
laminae  of  the  vertebra,  to  articulate  with  the  vertebra  above  and  below. 

Cervical  Vertebrce. — In  a  cervical  vertebra  the  body  is  smaller  than 
in  the  other  regions ;  it  is  thicker  before  than  behind,  broad  from  side 
to  side,  concave  on  the  upper  surface,  and  convex  below;  so  that,  when 
articulated,  the  vertebrae  lock  the  one  into  the  other.  The  lamirue  are 


CERVICAL    VERTEBRAE. 


51 


Fig.  16.« 


The  transverse  processes 


narrow  and  long,  and  the  included  spinal  fo- 
ramen large  and  triangular.  The  superior  in- 
tervertebral  notches  are  slightly  deeper  than  the 
inferior ;  the  inferior  being  the  broadest.  The 
spinous  process  is  short  and  bifid  at  the  extre- 
mity, increasing  in  length  from  the  fourth  to  the 
seventh.  The  transverse  processes  are  also  short 
and  bifid,  and  deeply  grooved  along  the  upper 
surface  for  the  cervical  nerves.  Piercing  the 
base  of  the  transverse  process  is  the  vertebral 
foramenf,  which  gives  passage  to  the  vertebral 
artery  and  vein,  and  vertebral  plexus  of  nerves. 

in  this  region  are  formed  by  two  small  developments  which  proceed,  the  one 
from  the  side  of  the  body,  the  other  from  the  pedicle  of  the  vertebra,  and 
unite  near  their  extremities  to  enclose  the  circular  area  of  the  vertebral 
foramen.  The  anterior  of  these  developments  is  the  rudiment  of  a  cervi- 
cal rib  ;  and  the  posterior,  the  analogue  of  the  transverse  processes  in  the 
dorsal  region.  The  extremities  of  these  developments  are  the  anterior 
and  posterior  tubercles  of  the  transverse  process.  The  articular  processes 
are  oblique  ;  the  superior  looking  upwards  and  backwards ;  and  the  infe- 
rior, downwards  and  forwards. 

There  are  three  peculiar  vertebrae  in  the  cervical  region : — The  first,  or 
atlas  ;  the  second,  or  axis ;  and  the  seventh,  or  vertebra  prominens. 

The  JJtlas  {named  from  supporting  the  head)  is  a  simple  ring  of  bone, 
without  body,  and  composed  of  arches  and  processes.  The  anterior  arch 
has  a  tubercle  on  its  anterior  surface,  for  the  attachment  of  thelongus  colli 
muscle :  and  on  its  posterior  aspect  is  a  smooth  surface,  for  the  articulation 
of  the  odontoid  process  of  the  axis. 

The  posterior  arch  is  longer  and  more 
slender  than  the  anterior,  and  flattened 
from  above  downwards ;  at  its  middle  is 
a  rudimentary  spinous  process ;  and  upon 
its  upper  surface,  near  the  articular  pro-  5, 
cesses,  a  shallow  groove  §  at  each  side, 
which  represents  a  superior  intervertebral 
notch,  and  supports  the  vertebral  artery 
previously  to  its  passage  through  the 
dura  mater,  and  the  first  cervical  nerve. 

*  A  central  cervical  vertebra,  seen  upon  its  upper  surface.  1.  The  body,  concave  in 
the  middle,  and  rising  on  each  side  into  a  sharp  ridge.  2.  The  lamina.  3.  The  pedi- 
cle, rendered  concave  by  the  superior  intervertebral  notch.  4.  The  bifid  spinous  process. 
5.  The  bifid  transverse  process.  The  figure  is  placed  in  the  concavity  between  the  an- 
terior and  posterior  tubercles,  between  the  two  processes  which  correspond  with  the 
rudimentary  rib  and  the  true  transverse  process.  6.  The  vertebral  foramen.  7.  The 
superior  articular  process,  looking  backwards  and  upwards.  8.  The  inferior  articular 
process. 

•}•  Sometimes,  as  in  a  vertebra  now  before  me,  a  small  additional  opening  exists  by 
the  side  of  the  vertebral  foramen,  in  which  case  it  is  traversed  by  a  second  vein. 

%  The  upper  surface  of  the  atlas.  1.  The  anterior  tubercle  projecting  from  the  ante- 
rior arch.  2.  The  articular  surface  for  the  odontoid  process  upon  the  posterior  surface 
of  the  anterior  arch.  3.  The  posterior  arch,  with  its  rudimentary  spinous  process.  4. 
The  intervertebral  notch.  5.  The  transverse  process.  6.  The  vertebral  foramen.  7. 
Superior  articular  surface.  8.  The  tubercle  for  the  attachment  of  the  transverse  liga- 
ment. The  tubercle  referred  to  is  just  above  the  head  of  the  figure ;  the  convexity  b*- 
iow  it  is  the  margin  of  the  inferior  articulating  process. 

§  This  groove  is  sometimes  converted  into  a  foramen. 


Fig.  17.* 


52          ATLAS  AND  AXIS — VERTEBRA  PROMINENS. 

The  intervertebral  notches  are  peculiar,  from  being  situated  behind  the 
articular  processes,  instead  of  before  them  as  in  the  other  vertebra.  The 
transverse  processes  are  remarkably  large  and  long,  and  pierced  by  the 
foramen  for  the  vertebral  artery.  The  articular  processes  are  situated  upon 
the  most  bulky  and  strongest  part  of  the  atlas.  The  superior  are  oval  and 
concave,  and  look  inwards,  so  as  to  form  a  kind  of  cup  for  the  condyles 
of  the  occipital  bone,  and  are  adapted  to  the  nodding  movements  of  the 
head ;  the  inferior  are  circular,  and  nearly  horizontal,  to  permit  of  the  ro- 
tatory movements.  Upon  the  inner  face  of  the  lateral  mass  which  sup- 
ports the  articular  processes,  is  a  small  tubercle  at  each  side,  to  which  the 
extremities  of  the  transverse  ligament  are  attached,  a  ligament  which  di- 
vides the  ring  of  the  atlas  into  two  unequal  segments ;  the  smaller  for 
receiving  the  odontoid  process  of  the  axis,  and  the  latter  to  give  passage 
to  the  spinal  cord  and  its  membranes. 

The  Axis  (vertebra  dentata)  is  so  named  from  having  a  process  upon 
which  the  head  turns  as  on  a  pivot.  The  body  is  of  large  size,  and  sup- 
ports a  strong  process,  the  odontoid,  which  rises  perpendicularly  from  its 
upper  surface.  The  odontoid  process  presents  two  articulating  surfaces ; 
one  on  its  anterior  face,  to  articulate  with  the  anterior  arch  of  the  atlas ; 
the  other  on  its  posterior  face,  for  the  transverse  ligament ;  the  latter  sur- 
face constricts  the  base  of  the  process,  which  has  given  rise  to  the  term  neck 
applied  to  this  part.  Upon  each  side  of  its  apex  is  a  rough  depression,  for 
the  attachment  of  the  alar  ligaments ;  and  running  down  from  its  base  on 
ri  lg«  the  anterior  surface  of  the  body  of  the  vertebra  a 

vertical  ridge,  with  a  depression  at  each  side  for 
the  attachment  of  the  longus  colli  muscle.  The 
lamina  are  large  and  strong,  and  unite  posteriorly 
to  form  a  long  and  bifid  spinous  process,  which  is 
concave  beneath.  The  transverse  processes  are 
quite  rudimentary,  not  bifid,  and  project  only  so 
far  as  to  enclose  the  vertebral  foramen,  which  is 
directed  obliquely  outwards  instead  of  perpendicu- 
larly as  in  the  other  vertebrae.  The  superior  articulating  processes  are 
situated  upon  the  body  of  the  vertebra  on  each  side  of  the  odontoid  process, 
They  are  circular  and  nearly  horizontal,  having  a  slight  inclination  out- 
wards. The  inferior  articulating  processes  look  downwards  and  forwards, 
as  do  the  same  processes  in  the  other  cervical  vertebrae.  The  superior  in- 
tervertebral notch  is  remarkably  shallow,  and  lies  behind  the  articular  pro- 
cess as  in  the  atlas.  The  lower  surface  of  the  body  is  convex,  and  is 
received  into  the  concavity  upon  the  upper  surface  of  the  third  vertebra. 

The  Vertebra  prominens,  or  seventh  cervical,  approaches  in  character 
to  the  upper  dorsal  vertebrae.  It  has  received  its  designation  from  having 
a  very  long  spinous  process,  which  is  single  and  terminated  by  a  tubercle, 
and  forms  a  considerable  projection  on  the  back  part  of  the  neck ;  to  the 
extremity  of  this  process  the  ligamentum  nuchae  is  attached.  The  trans- 
verse processes  are  but  slightly  grooved  along  the  upper  surface,  have 

*  A  lateral  view  of  the  axis.  1.  The  body;  the  figure  is  placed  on  the  depression 
which  gives  attachment  to  the  longus  colli.  2.  The  odontoid  process.  3.  The  smooth 
facet  on  the  anterior  surface  of  the  odontoid  process  which  articulates  with  the  anterior 
arch  of  the  atlas ;  the  facet  for  the  transverse  ligament  is  beneath  No.  2,  where  the 
constriction  called  the  neck  of  the  odontoid  process  is  seen;  the  bulk  of  the  process  be- 
tween 2,  3,  would  represent  its  head.  4.  The  lamina.  5.  The  spinous  process.  6 
The  transverse  process,  pierced  obliquely  by  the  vertebral  foramen.  7.  The  superior 
articular  surface.  8.  Thb  inferior  articular  process 


DORSAL  VERTEBRAE LUMBAR  VERTEBRAE. 


53 


19.' 


each  a  small  foramen  for  the  transmission  of  the  vertebral  vein,  and  pre- 
sent only  a  rudimentary  bifurcation  at  their  extremity.  Sometimes  the 
anterior  tubercle  represents  a  small  but  distinct  rib. 

Dorsal  Vertebra. — The  body  of  a  dorsal  vertebra  is  as  long  from  before 
backwards  as  from  side  to  side,  particularly  in  the  middle  of  the  dorsai 
region ;  it  is  thicker  behind  than  before,  and  marked  on  each  side  by  two 
half-articulating  surfaces  for  the  heads  of  two  ribs.  The  pedicles  are  strong, 
and  the  lamina  broad  and  thick ;  the  spinal  foramen  small  and  round, 
and  the  inferior  intervertebral  notch  of  large 
size,  the  superior  can  scarcely  be  said  to  exist. 
The  spinous  process  is  long,  prismoid,  directed 
very  obliquely  downwards,  and  terminated  by 
a  tubercle.  The  transverse  processes  are  large 
and  strong,  and  directed  obliquely  back- 
wards. Upon  the  anterior  and  superior  as- 
pect of  their  summits  is  a  small  facet  for  the 
articulation  of  the  tubercle  of  a  rib.  The  ar- 
ticular processes  are  vertical,  the  superior  facing 
directly  backwards,  and  the  inferior  directly 
forwards. 

The  peculiar  vertebrae  in  the  dorsal  region  are  the  first,  ninth,  tenth, 
eleventh,  and  twelfth.  Thejirst  dorsal  vertebra  approaches  very  closely 
in  character  to  the  last  cervical.  The  body  is  broad  from  side  to  side, 
and  concave  above.  The  superior  articular  processes  are  oblique,  and 
the  spinous  process  horizontal.  It  has  an  entire  articular  surface  for  the 
first  rib,  and  a  half  surface  for  the  second.  The  ninth  dorsal  vertebra  has 
only  one  half  articular  surface  at  each  side.  The  tenth  has  a  single  entire 
articular  surface  at  each  side.  The  eleventh  and  twelfth  have  each  a  single 
entire  articular  surface  at  each  side ;  they  approach  in  character  to  the 
lumbar  vertebrae  ;  their  transverse  processes  are  very  short,  trifid  at  their 
summits,  and  have  no  articulation  with  the  corresponding  ribs.  The 
transverse  processes  of  the  twelfth  dorsal  vertebra  are  quite  rudimentary, 
and  its  inferior  articular  processes  look  outwards. 

Lumbar  Vertebra. — These  are  the  largest 
pieces  of  the  vertebral  column.  The  body 
is  broad  and  large,  and  thicker  before  than 
behind.  The  pedicles  very  strong;  the  la- 
mina short,  thick,  and  broad  ;  the  inferior 
intervertebral  notches  very  large,  and  the 
spinal  foramen  large  and  oval.  The  spin- 
ous process  is  thick  and  broad.  The  trans- 
verse processes  (costifonn  processes)  are  -.-/^ 
slender,  pointed,  and  directed  only  slightly 

*  A  lateral  view  of  a  dorsal  vertebra.  1.  The  body.  2,  2.  Articular  facets  for  the 
heads  of  ribs.  3.  The  pedicle.  4.  The  superior  intervertebral  notch.  5.  The  inferior 
intervertebral  notch.  6.  The  spinous  process.  7.  The  extremity  of  the  transverse  pro- 
cess, marked  by  an  articular  surface  for  the  tubercle  of  a  rib.  8.  The  two  superior 
articular  processes  looking  backwards.  9.  The  two  inferior  articular  processes  looking 
forwards. 

•(•  A  lateral  view  of  a  lumbar  vertebra.  1.  The  body.  2.  The  pedicle.  3.  The  su- 
perior intervertebral  notch.  4.  The  inferior  intervertebra;  notch.  5.  The  spinous  pro- 
cess. 6.  The  transverse  process.  7.  The  superior  articular  processes.  8.  The  inferioi 
articular  processes.  9.  The  posterior  transverse  process. 

5* 


5-1  LUMBAR   VERTEBRAE. 

backwards.  The  superior  articular  processes  are  concave,  and  look  back- 
wards and  inwards ;  the  inferior  convex,  and  look  forwards  and  outwards. 
Projecting  backwards  and  upwards  from  the  superior  articular  process  is 
a  short  and  flattened  tubercle  or  posterior  transverse  process,  and  in  a 
strongly  marked  vertebra  there  is  not  unfrequently  at  the  base  of  this  a 
smaller  tubercle  which  has  a  direction  downwards.  The  last  lumbar  ver- 
tebra differs  from  the  rest  in  having  the  body  very  much  bevelled  poste- 
riorly, so  as  to  be  thick  in  front  and  thin  behind,  and  the  transverse  pro- 
cess thick  and  large. 

General  Considerations. — Viewed  as  a  whole,  the  vertebral  column 
represents  two  pyramids  applied  base  to  base,  the  superior  being  formed 
by  all  the  vertebrae  from  the  second  cervical  to  the  last  lumbar,  and  the 
inferior  by  the  sacrum  and  coccyx.  Examined  more  attentively,  it  will 
be  seen  to  be  composed  of  four  irregular  pyramids,  applied  to  each  other 
by  their  smaller  extremities  and  by  their  bases.  The  smaller  extremity 
of  the  uppermost  pyramid  is  formed  by  the  axis,  or  second  cervical  ver- 
tebra ;  and  its  base,  by  the  first  dorsal.  The  second  pyramid  is  inverted ; 
having  its  base  at  the  first  dorsal,  and  the  smaller  end  at  the  fourth.  The 
third  pyramid  commences  at  the  fourth  dorsal,  and  gradually  enlarges  to 
the  fifth  lumbar.  The  fourth  pyramid  is  formed  by  the  sacrum  and 
coccyx. 

The  bodies  of  the  vertebrae  are  broad  in  the  cervical  region ;  narrowed 
almost  to  an  angle  in  the  middle  of  the  dorsal,  and  again  broad  in  the 
lumbar  region.  The  arches  are  broad  and  imbricated  in  the  cervical  and 
dorsal  regions,  the  inferior  border  of  each  overlapping  the  superior  of  the 
next ;  in  the  lumbar  region  an  interval  is  left  between  them.  A  consider- 
able interval  exists  between  the  cranium  and  atlas,  and  another  between 
the  last  lumbar  vertebra  and  sacrum. 

The  spinous  processes  are  horizontal  in  the  cervical,  and  become  gradu- 
ally oblique  in  the  upper  part  of  the  dorsal  region.  In  the  middle  of  the 
dorsal  region  they  are  nearly  vertical  and  imbricated,  and  towards  its 
lower  part  assume  the  direction  of  the  lumbar  spines,  which  are  quite 
horizontal.  The  transverse  processes  developed  in  their  most  rudimentary 
form  in  the  axis,  gradually  increase  in  length  to  the  first  dorsal  vertebra. 
In  the  dorsal  region  they  project  obliquely  backwards,  and  diminish  sud- 
denly in  length  in  the  eleventh  and  twelfth  vertebrae  where  they  are  very 
small.  In  the  lumbar  region  they  increase  to  the  middle  transverse  pro- 
cess, and  again  subside  in  length  to  the  last. 

The  transverse  processes  consist  essentially  of  two  parts,  the  anterior 
of  which  in  the  dorsal  region  is  the  rib,  while  the  posterior  retains  the 
name  of  the  transverse  process.  In  the  cervical  region  these  two  elements 
are  quite  apparent,  both  by  their  different  points  of  attachment  to  the  ver- 
tebra, and  by  the  vertebral  foramen  which  divides  them  at  their  base.  In 
the  lumbar  region  the  so-called  transverse  processes  are  in  reality  lumbar 
ribs,  while  the  transverse  processes  will  be  found  behind  them  in  a  rudi- 
mentary state,  developed,  like  the  true  transverse  processes  in  the  cervical 
region,  from  the  superior  articular  processes.  When  the  anterior  and 
posterior  transverse  processes  are  examined  in  relation  with  each  other, 
they  will  be  observed  to  converge ;  if  they  were  prolonged  they  would 
unite  as  in  the  cervical  region  and  enclose  a  foramen,  or  they  would  rest 
in  contact  as  in  the  dorsal  region,  or  become  consolidated  as  in  the  form- 
ation of  the  sacrum.  Moreover,  the  posterior  transverse  processes  -ire 


DEVELOPMENT  OF  VERTEBRAE.  55 

directed  upwards,  and  if  they  were  prolonged,  they  would  come  into  con- 
tact with  a  small  tubercle  which  is  found  at  the  base  of  the  posterior  trans- 
verse process  (in  strongly-marked  vertebrae)  in  the  vertebra  above.  This 
junction  would  form  a  posterior  intervertebral  foramen,  as  actually  occurs 
in  the  sacrum.  In  brief,  the  lumbar  vertebrae  exhibit  those  transitional 
changes  which  are  calculated,  by  an  easy  gradation,  to  convert  separate 
vertebrae  into  a  solid  bone.  The  transverse  processes  of  the  eleventh  and 
twelfth  dorsal  vertebrae  are  very  interesting  in  a  transcendental  point  of 
view,  as  exhibiting  a  tendency  which  exists  obscurely  in  all  the  rest, 
namely,  to  trifurcate.  Now,  supposing  these  three  branches  to  be  length- 
ened in  order  to  fulfil  their  purposes,  the  anterior  would  constitute  the 
articulation  or  union  with  a  rib,  while  the  superior  and  inferior  would  join 
similar  branches  in  the  vertebra  above  and  below,  and  so  form  the  poste- 
rior intervertebral  foramen. 

The  intervertebral  foramina  formed  by  the  juxtaposition  of  the  notches 
are  smallest  in  the  cervical  region,  and  gradually  increase  to  the  last  lum- 
bar. On  either  side  of  the  spinous  processes,  and  extending  the  whole 
length  of  the  column,  is  the  vertebral  groove,  which  is  shallow  and  broad 
in  the  cervical,  and  deeper  and  narrower  in  the  dorsal  and  lumbar  regions. 
It  lodges  the  principal  muscles  of  the  back. 

Viewed  from  the  side,  the  vertebral  column  presents  several  curves,  the 
principal  of  which  is  situated  in  the  dorsal  region,  the  concavity  looking    ' 
forwards.     In  the  cervical  and  lumbar  regions  the  column. is  convex  in 
front ;  and  in  the  pelvis  an  anterior  concave  curve  is  formed  by  the  sacrum 
and  coccyx.     Besides  the  antero-posterior  curves,  a  slight  lateral  curve    . 
exists  in  the  dorsal  region,  having  its  convexity  towards  the  right  side. 

Development. — The  vertebrae  are  developed  by  three  primary  and  five 
secondary  centres  or  epiphyses.  The  primary  centres  are,  one  for  each 
lamella,  and  one  for  the  body ;  the  epiphyses,  one  for  the  apex  of  the 
spinous  process,  one  for  that  of  each  transverse  process,  and  one  for  the 
upper  and  under  surface  of  the  body.  Exceptions  to  this  mode  of  deve- 
lopment are  met  with  in  the  atlas,  axis,  vertebra  prominens,  and  lumbar 
vertebrae.  The  atlas  has  four  centres:  one  for  each  lateral  mass,  one 
(sometimes  two)  for  the  anterior  arch,  and  one  for  the  centre  of  the  poste- 
rior arch.  The  axis  has  five :  one  (sometimes  two)  for  the  body,  two  for 
the  odontoid  process,  appearing  side  by  side  in  its  base,  and  one  for  each 
lamella.  The  vertebra  prominens  has  two  additional  centres  for  the  ante- 
rior or  costal  segments  of  the  transverse  processes,  and  the  lumbar  vertebras 
two  for  the  posterior  segments  of  the  transverse  processes. 

The  primary  centres  of  the  vertebrae  make  their  appearance  during  the 
seventh  or  eighth  week  of  embryonic  existence,  the  lamella  being  some- 
what in  advance  of  that  for  the  body.  From  the  former  are  produced  the 
spinous,  transverse,  and  articular  processes,  and  the  sides  of  the  body ; 
they  unite,  to  complete  the  arch,  one  year  after  birth,  and  with  the  body 
during  the  fifth  year.  The  epiphyses,  for  the  extremities  of  the  spinous 
and  transverse  processes,  make  their  appearance  at  fifteen  or  sixteen,  and 
become  united  between  twenty  and  twenty-five.  The  epiphyses  of  the 
body  are  somewhat  later  in  appearance,  and  are  consolidated  between  the 
periods  of  twenty-five  and  thirty  years  of  age. 

The  ossific  centres  for  the  lateral  masses  of  the  atlas  appear  at  the  same 
time  with  those  of  the  other  vertebrae ;  they  unite  posteriorly  at  the  end 
of  the  second  year,  by  the  intervention  of  the  centre  for  the  posterior  arch. 


56  SACRUM. 

The  one  or  two  centres  of  the  anterior  arch  appear  during  the  first  year, 
and  become  consolidated  with  the  lateral  pieces  during  the  lifth  or  sixth 
year.  The  axis  develops  its  lateral  pieces  at  the  same  time  with  the  rest 
of  the  vertebrae  ;  they  join  posteriorly  soon  after  birth,  and  with  the  body 
during  the  fourth  or  fifth  year.  The  centres  for  the  body  and  odontoid 
process  appear  during  the  sixth  month,  and  are  consolidated  during  the 
third  year.  The  body  of  the  axis  is  more  largely  developed  at  birth  than 
that  of  the  other  vertebrae.  The  costal  segments  of  the  vertebra  prominens 
appear  during  the  second  month,  and  become  united  to  the  body  at  the 
fifth  or  sixth  year.  These  processes  sometimes  remain  permanently  sepa- 
rate, and  constitute  a  cervical  rib.  The  transverse  process  of  the  first 
lumbar  vertebra  has  sometimes  a  distinct  centre,  which  may  remain  per- 
manently separate,  in  that  case  forming  a  lumbar  rib. 

The  ossification  of  the  arches  of  the  vertebrae  commences  from  above, 
and  proceeds  gradually  downwards ;  hence  arrest  of  development  give? 
rise  to  spina  bifida,  generally  in  the  loins.  Ossification  of  the  bodies,  OR 
the  contrary,  commences  from  the  centre,  and  proceeds  from  that  point 
towards  the  extremities  of  the  column ;  hence  imperfection  of  the  bodies 
occurs  either  in  the  upper  or  lower  vertebras. 

•Attachment  of  Muscles. — To  the  atlas  are  attached  ten  pairs  of  muscles; 
the  longus  colli,  rectus  anticus  minor,  rectus  lateralis,  rectus  posticus 
minor,  obliquus  superior  and  inferior,  splenius  colli,  levator  anguli  scapulas, 
first  interspinales,  and  first  intertransversales. 

To  the  axis  are  attached  twelve  pairs,  viz. :  the  longus  colli,  intertrans- 
versales, obliquus  inferior,  rectus  posticus  major,  supraspinalis,  interspi- 
nales, semi-spinalis  colli,  multifidus  spinae,  levator  anguli  scapulas,  splenius 
colli,  transversalis  colli,  and  scalenus  posticus. 

To  the  remaining  vertebra  collectively,  thirty-three  pairs ; — viz.  poste- 
riorly, the  trapezius,  latissimus  dorsi,  levator  anguli  scapulas,  rhomboideus 
minor  and  major,  serratus  posticus  superior  and  inferior,  splenius,  sacro- 
lumbalis,  longissimus  dorsi,  spinalis  dorsi,  cervicalis  ascendens,  trans- 
versalis colli,  trachelo-mastoideus,  complexus,  semi-spinalis  dorsi  and 
colli,  multifidus  spinas,  supraspinalis,  interspinales,  intertransversales, 
levatores  costarum :  anteriorly,  the  rectus  anticus  major,  longus  colli, 
scalenus  anticus  and  posticus,  psoas  magnus,  psoas  parvus,  quadratus 
Jumborum,  diaphragm,  obliquus  internus  and  transversalis. 

THE  SACRUM  is  a  triangular  bone,  situated  at  the  lower  extremity  of  the 
vertebral  column,  and  formed  by  the  consolidation  of  five  false  vertebras. 
It  is  divisible  into  an  anterior  and  posterior  surface,  two  lateral  and  a 
superior  border,  and  an  inferior  extremity. 

The  anterior  surface  is  concave,  and  marked  by  four  transverse  lines, 
which  indicate  its  original  constitution  of  five  separate  pieces.  At  the 
extremities  of  these  lines,  on  each  side,  are  the  four  anterior  sacral  fora- 
mina, which  diminish  in  size  from  above  downwards,  and  transmit  the 
anterior  sacral  nerves.  The  projection  of  the  superior  piece  is  the  sacro- 
vertebral  angle  or  promontory. 

The  posterior  surface  is  narrower  than  the  anterior  and  convex.  Upon 
the  middle  line  is  a  rough  crest  formed  by  the  rudiments  of  four  spinous 
processes,  the  fifth  remaining  undeveloped  and  exposing  the  lower  termi- 
nation of  the  ?acral  canal.  Immediately  external  to  and  parallel  with  the 
median  crest,  is  a  range  of  five  small  tubercles  which  represent  the  poste- 


SACRUM.  57 

nor  transverse  processes  of  the  true  vertebrae ;  beyond  these  is  a  shallow 
groove  in  which  the  four  posterior  sacral  foramina  open,  and  farther  out- 
wards, a  range  of  five  tubercles  corresponding  with  the  anterior  or  costal 
transverse  processes  of  the  lumbar  vertebra.  The  lowest  pair  of  the  pos- 
terior transverse  tubercles  bound  on  each  side  the  termination  of  the  sacral 
canal,  and  send  each  a  process  downwards  to  articulate  with  the  coccyx. 
The  two  descending  processes  are  the  sacral  cornua.  The  posterior  sacral 
foramina  are  smaller  than  the  anterior,  and  transmit  the  posterior  sacral 
nerves.  Of  the  anterior  transverse  tubercles  fiie  first  corresponds  with  the 
angle  of  the  superior  border  of  the  bone ;  the  second  is  small,  and  enter? 
into  the  formation  of  the  sacro-iliac  articulation ;  the  Hhird  is  large,  and 
gives  attachment  to  the  oblique  sacro-iliac  ligament ;  -the  fourth  and  fifth 
are  smaller,  and  serve  for  the  attachment  of  the 
sacro-ischiatic  ligaments.  The  lateral  border 
of  the  sacrum  presents  superiorly  a  broad  and 
ear-shaped  (auricular)  surface  to  articulate  with 
the  ilium ;  and  inferiorly  a  sharp  edge,  to  which 
the  greater  and  lesser  sacro-ischiatic  ligaments 
are  attached.  On  the  superior  border,  in  the 
middle  line,  is  an  oval  articular  surface,  which 
corresponds  with  the  under  part  of  the  body  of 
the  last  lumbar  vertebra ;  and  on  each  side  a 
broad  triangular  surface,  which  supports  the 
lumbo-sacral  nerve  and  psoas  magnus  muscle. 
Immediately  behind  the  vertebral  articular  sur- 
face is  the  triangular  entrance  of  the  sacral  canal ;  and  on  each  side  of  this 
opening  an  articular  process,  which  looks  backwards  and  inwards,  like  the 
superior  articular  processes  of  the  lumbar  vertebrae.  In  front  of  each 
articular  process  is  an  intervertebral  notch.  The  inferior  extremity  of  the 
bone  presents  a  small  oval  surface  which  articulates  with  the  coccyx ;  and 
on  each  side  a  notch,  which,  with  a  corresponding  notch  in  the  upper 
border  of  the  coccyx,  forms  the  foramen  for  the  transmission  of  the  fifth 
sacral  nerve. 

The  sacrum  presents  some  variety  in  respect  of  curvature,  and  of  the 
number  of  pieces  which  enter  into  its  structure.  The  curve  is  often  very 
slight,  and  is  situated  only  near  the  lower  part  of  the  bone ;  while  in  other 
subjects  it  is  considerable,  and  occurs  at  the  middle  of  the  sacrum.  The 
sexual  differences  in  the  sacrum  relate  to  its  greater  breadth,  and  the 
greater  angle  which  it  forms  with  the  rest  of  the  vertebral  column  in  the 
female,  rather  than  to  any  peculiarity  in  shape.  It  is  sometimes  composed 
of  six  pieces,  more  rarely  of  four,  and,  occasionally,  the  first  and  second 
pieces  remain  permanently  separate. 

Development. — By  twenty-one  points  of  ossification ;  five  for  each  of  the 
three  first  pieces,  viz.  one  for  the  body,  one  for  each  lateral  portion,  and 
one  for  each  lamina ;  and  three  for  each  of  the  two  last,  namely,  one  for 

*  The  sacrum  seen  upon  its  anterior  surface.  1,  1.  The  transverse  lines  marking  the 
original  constitution  of  the  bone  of  four  pieces.  2,  2.  The  anterior  sacral  foramina. 
3.  The  promontory  of  the  sacrum.  4.  The  ear-shaped  surface  which  articulates  witli 
the  ilium.  5.  The  sharp  edge  to  which  the  sacro-ischiatic  ligaments  are  attached. 
6.  The  vertebral  articular  surface.  7.  The  broad  triangular  surface  which  supports  the 
psoas  muscle  and  lumbo-sacral  nerve.  8.  The  articular  process  of  the  right  side 
9.  The  inferior  extremity,  or  apex  of  the  sacrum.  10.  One  of  the  sacral  cornua 
1 1.  The  notch  which  is  converted  into  a  foramen  by  the  coccyx. 


58  COCCYX. 

the  body,  and  one  for  each  lateral  portion.  In  the  progress  of  growth, 
and  after  puberty,  fourteen  epiphysal  centres  are  added,  namely,  two  for 
the  surfaces  of  each  body,  one  for  each  auricular  surface,  and  one  for  the 
thin  edge  of  each  lateral  border.  Ossification  begins  in  the  bodies  of  the 
sacral  pieces  somewhat  later  than  in  those  of  the  true  vertebrae  ;  the  first 
three  appearing  during  the  eighth  and  ninth  week,  and  the  last  two  al  about 
the  middle  of  the  intra-uterine  existence.  Ossification  of  the  lamelke 
takes  place  during  the  interval  between  the  sixth  and  the  ninth  month. 
The  epiphyses  for  the  upper  and  under  surface  of  the  bodies  are  developed 
during  the  interval  between  the  fifteenth  and  eighteenth  year;  and  for  the 
auricular  and  marginal  piece,  after  twenty.  The  two  lower  vertebral 
pieces,  although  the  last  to  appear,  are  the  first  to  be  completed  (between 
the  fourth  and  fifth  year),  and  to  unite  by  their  bodies.  The  union  of  the 
bodies  takes  place  from  below  upwards,  and  finishes  between  the  twenty- 
fifth  and  the  thirtieth  year,  with  the  first  two  pieces. 

Articulations.  —  With  four  bones  ;  the  last  lumbar  vertebra,  ossa  inno- 
minata,  and  coccyx. 

Attachment  of  Muscles.  —  To  seven  pairs;  in  front  the  pyriformis,  on 
the  side  the  coccygeus,  and  behind  the  gluteus  maximus,  latissimus  dorsi, 
longissimus  dorsi,  sacro-lumbalis,  and  multifidus  spinaB. 


The  COCCYX  (xoxxug  cuckoo,  from  resembling  a  cuckoo's  beak)  is  com- 
posed of  four  small  pieces,  which  form  the  caudal  termination  of  the  ver- 
tebral column.  The  superior  piece  is  broad,  and  expands  laterally  into 
two  transverse  processes  ;  it  is  surmounted  by  an  oval  articular  surface 
and  two  cornua,  the  former  to  articulate  with  the  apex  of  the  sacrum,  and 
the  latter  with  the  sacral  cornua.  The  lateral  wings  sometimes  become 
connected  with  the  sacrum,  and  convert  the  notches  for  the  fifth  pair  of 
sacral  nerves  into  foramina.  The  remaining  three  pieces  diminish  in  size 
from  above  downwards. 

Development.  —  By  four  centres  ;  one  for  each  piece.  Ossification  com- 
mences in  the  first  piece  soon  after  birth  ;  in  the  second,  between  five  and 
ten  years  ;  in  the  third,  between  ten  and  fifteen  ;  and  in  the  fourth,  be- 
tween fifteen  and  twenty.  The  pieces  unite  at  an  earlier  period  than  the 
bodies  of  the  sacrum,  the  first  two  pieces  first,  then  the  third  and  fourth, 
and  lastly,  the  second  and  third.  Between  forty  and  sixty  years,  the 
coccyx  becomes  consolidated  with  the  sacrum  ;  this  event  taking  place 
later  in  the  female  than  in  the  male. 

Articulations.  —  With  the  sacrum. 

Attachment  of  Muscles.  —  To  three  pairs,  and  one  single  muscle;  gluteus 
maximus,  coccygeus,  posterior  fibres  of  the  levator  ani,  and  sphincter  ani. 

OF     THE     SKULL. 

The  skull,  or  superior  expansion  of  the  vertebral  column,  is  divisible 
into  two  parts,  —  the  cranium  and  the  face  ;  the  former  being  adapted,  by 
its  form,  structure,  and  strength,  to  contain  and  protect  the  brain,  and  the 
Jatter  the  chief  organs  of  sense. 

The  CRANIUM  is  composed  of  eight  separate  bones  ;  viz.,  the 
Occipital,  Two  temporal, 

Two  parietal,  Sphenoid, 

Frontal,  Ethmoid. 


OCCIPITAL   BONE.  59 

OCCIPITAL  BONE. — This  bone  is  situated  at  the  posterior  part  and  base 
of  the  cranium.  It  is  trapezoid  in  figure,  and  divisible  into  two  surfaces, 
four  borders,  and  four  angles. 

External  Surface. — Crossing  the  middle  of  the  bone  transversely,  from 
one  lateral  angle  to  the  other,  is  a  prominent  ridge,  the  superior  curved 
line.     In  the  middle  of  the  ridge  is  a 
projection,  called  the  external  occipital  Fig.  22.* 

protuberance ;  and  descending  from  it  a  ^-r^1-*^-. 

11         •    i    •  -i  •  ~^^B 

small  vertical  ridge,  the  spine.     Above  ^''  ^ 

and  below  the  superior  curved  line  the         /,  x\ 

surface  is  rough,  for  the  attachment  of      /  .  .....      \ 

muscles.  About  three-quarters  of  an 
inch  below  this  line  is  another  trans- 
verse ridge,  the  inferior  curved  line, 
and  beneath  the  latter  {he  foramen  mag- 
num. On  each  side  of  the  foramen 
magnum,  nearer  to  its  anterior  than 
its  posterior  segment,  and  encroaching 
somewhat  upon  the  opening,  is  an  ob- 
long articular  surface,  the  condyle,  for 
articulation  with  the  atlas.  The  con- 
dyles  approach  towards  each  other  an- 
teriorly, and  their  articular  surfaces  look  downwards  and  outwards. 
Directly  behind  each  condyle  is  an  irregular  fossa,  and  a  small  opening, 
the  posterior  condyloid  for -amen ,,for  the  transmission  of  a  vein  to  the  lateral 
sinus.  In  front  of  the  condyle  is  the  anterior  condyloid  foramen,  for  the 
hypoglossal  nerve ;  and  on  the  outer  side  of  each  condyle  a  projecting 
ridge,  the  transverse  process,  excavated  in  front  by  a  notch  which  forms 
part  of  the  jugular  foramen.  In  front  of  the  foramen  magnum  is  a  thick 
square  mass,  the  basilar  process,  and  in  the  centre  of  the  basilar  process  a 
small  tubercle  for  the  attachment  of  the  superior  and  middle  constrictor 
muscles  of  the  pharynx. 

Internal  Surface.  —  Upon  the  internal  surface  is  a  crucial  ridge,  which 
divides  the  bone  into  four  fossa ;  the  two  superior  or  cerebral  fossae  lodging 
the  posterior  lobes  of  the  cerebrum ;  and  the  two  inferior  or  cerebellar, 
the  lateral  lobes  of  the  cerebellum.  The  superior  arm  of  the  crucial  ridge 
is  grooved  for  the  superior  longitudinal  sinus,  and  gives  attachment  to  the 
falx  cerebri ;  the  inferior  arm  is  sharp  and  prominent,  for  the  attachment 
of  the  falx  cerebelli,  and  slightly  grooved  for  the  two  occipital  sinuses. 
The  transverse  ridge  gives  attachment  to  the  tentorium  cerebelli,  and  is 
deeply  grooved  for  the  lateral  sinuses.  At  the  point  of  meeting  of  the 
four  arms  is  a  projection,  the  internal  occipital  protuberance,  which  corre 
sponds  with  the  similar  process  situated  upon  the  external  surface  of  the 
bone.  The  convergence  of  the  four  grooves  forms  a  slightly  depressed 
fossa,  upon  which  rests  the  torcular  Herophili.  In  the  centre  of  the 

*  The  external  surface  of  the  occipital  bone.  1.  The  superior  curved  line.  2.  The 
external  occipital  protuberance.  3.  The  spine.  4.  The  inferior  curved  line.  5.  The 
foramen  magnum.  6.  The  condyle  of  the  right  side.  7.  The  posterior  condyloid  fossa, 
in  which  the  posterior  condyloid  foramen  is  found.  8.  The  anterior  condyloid  foramen, 
concealed  by  the  margin  of  the  condyle.  9.  The  transverse  process;  this  process  upon 
the  internal  surface  of  the  bone  forms  the  jugular  eminence.  10.  The  notch  in  front  or 
the  jugular  eminence  which  forms  part  of  the  Jugular  foramen.  1 1.  The  basilar  process 
12.  12.  The  rough  projections  into  which  the  odontoid  ligaments  are  inserted. 


60 


OCCIPITAL    BONE. 


Fig.  23.' 


basilar  portion  of  the  bone  is  the  foramen  magnum,  oblong  in  form,  and 
larger  behind  than  before,  t/ransmitting  the  spinal  cord,  spinal  accessory 

nerves,  and  vertebral  arteries.  Upon 
the  lateral  margins  of  the  foramen 
magnum  are  two  rough  eminences, 
which  give  attachment  to  the  odon- 
toid ligaments,  and  immediately  above 
these  the  openings  of  the  anterior  con- 
dyloid  foramina.  In  front  of  the  fora- 
men magnum  is  the  basilar  process, 
grooved  on  its  surface,  for  supporting 
the  medulla  oblongata,  and  along  each 
lateral  border,  for  the  inferior  petrosal 
sinuses.  On  each  side  of  the  foramen 
magnum  is  a  groove,  for  the  termina- 
tion of  the  lateral  sinus ;  a  smooth  sur- 
face, which  forms  part  of  the  jugular 
fossa ;  and  a  projecting  process,  which 
divides  the  two,  and  is  called  the 
jugular  eminence.  Into  the  jugular 
fossa  will  be  seen  opening  the  posterior  condyloid  foramen. 

The  superior  borders  are  very  much  serrated,  and  assist  in  forming  the 
lambdoidal  suture ;  the  inferior  are  rough,  but  not  serrated,  and  articulate 
with  the  mastoid  portion  of  the  temporal  bone  by  means  of  the  p'ldita- 
mentum  suturae  lambdoidalis.  The  jugular  eminence  and  the  side  of  the 
basilar  process  articulate  with  the  petrous  portion  of  the  temporal  bone, 
and  the  intermediate  space,  which  is  irregularly  notched,  forms  the  poste- 
rior boundary  of  the  jugular  foramen,  or  foramen  lacerum  posterius. 

The  angles  of  the  occipital  bone  are  the  superior,  inferior,  and  two 
lateral.  The  superior  angle  is  received  into  the  interval  formed  by  the 
union  of  the  posterior  and  superior  angles  of  the  parietal  bones,  and  cor- 
responds with  that  portion  of  the  fetal  head  which  is  called  the  posterior 
fontanelle.  The  inferior  angle  is  the  articular  extremity  of  the  basilar 
process.  The  lateral  angles  at  each  side  project  into  that  interval  formed 
by  the  articulation  of  the  posterior  and  inferior  angle  of  the  parietal  with 
the  mastoid  portion  of  the  temporal  bone. 

Development. — By  seven  centres  ;  four  for  the  four  parts  of  the  expanded 
portion  divided  by  the  crucial  ridge,  one  for  each  condyle,  and  one  for 
the  basilar  process.  Ossification  commences  in  the  expanded  portion  of 
the  bone  at  a  period  anterior  to  the  vertebra  ;  at  birth  the  four  remaining 
pieces  are  distinct;  they  are  united  at  about  the  fifth  or  sixth  year.  After 
twenty  the  basilar  process  unites  with  the  body  of  the  sphenoid. 

*The  internal  surface  of  the  occipital  bone.  1.  The  left  cerebral  fossa.  2.  The  left 
cerebellar  fossa.  3.  The  groove  for  the  posterior  part  of  the  superior  longitudinal  sinus. 
4.  The  spine  for  the  falx  cerebelli,  and  groove  for  the  occipital  sinuses.  5.  The  groove 
for  the  left  lateral  sinus.  6.  The  internal  occipital  protuberance,  the  groove  on  which 
lodges  the  torcular  Herophili.  7.  The  foramen  magnurn.  8.  The  basilar  process, 
grooved  for  the  medulla  oblongata.  9.  The  termination  of  the  groove  for  the  lateral 
sinus,  bounded  externally  by  the  jugular  eminence.  10.  The  jugular  fossa;  this  fossa 
is  completed  by  the  petrous  portion  of  the  temporal  bone.  11.  The  superior  border. 
12.  The  inferior  border.  13.  The  border  which  articulates  with  the  petrous  portion  of 
the  temporal  bone,  and  which  is  grooved  by  the  inferior  petrosal  sinus.  14.  The  ame 
rior  condy'oid  foramen. 


PARIETAL    BONE. 


61 


Articulations. — With  six  bones ;  two  parietal,  two  temporal,  sphenoid 
and  atlas. 

Attachment  of  Muscles. — To  thirteen  pairs:  to  the  rough  surface  above 
the  superior  curved  line,  the  occipito-frontalis ;  to  the  superior  curved 
line,  the  trapezius  and  sterno-mastoid ;  to  the  rough  space  between  the 
curved  lines,  complexus,  and  splenius  capitis ;  to  the  space  between  the 
inferior  curved  line  and  the  foramen  magnum,  the  rectus  posticus  major 
and  minor,  and  obliquus  superior;  to  the  transverse  process,  the  rectus 
Jateralis ;  and  to  the  basilar  process,  the  rectus  anticus  major  and  minor, 
and  superior  and  middle  constrictor  muscles. 


Fig.  24« 


PARIETAL  BONE.  —  The  parietal 
bone  is  situated  at  the  side  and  ver- 
tex of  the  skull ;  it  is  quadrilateral  in 
form,  and  divisible  into  an  external 
and  internal  surface,  four  borders  and 
four  angles.  The  superior  border  is 
straight,  to  articulate  with  its  fellow 
of  the  opposite  side.  The  inferior 
border  is  arched  and  thin,  to  articu-  3'j 
late  with  the  temporal  bone.  The 
anterior  border  is  concave,  and  the 
posterior  somewhat  convex. 

External  surface.  —  Crossing  the 
bone  in  a  longitudinal  direction  from 
the  anterior  to  the  posterior  border,  is  an  arched  line,  the  temporal  ridgey 
to  which  the  temporal  fascia  is  attached.  In  the  middle  of  this  line,  and 
nearly  in  the  centre  of  the  bone,  is  the  projection  called  the  parietal  emi- 
nence, which  marks  the  centre  of  ossification.  Above  the  temporal  ridge 
the  surface  is  rough,  and  covered  by  the  aponeurosis  of  the  occipito-fron- 
talis ;  below  the  ridge  the  bone  is  smooth  (planum  semicircular  e],  for  the 
attachment  of  the  fleshy  fibres  of  the  temporal  muscle.  Near  the  superior 
border  of  the  bone,  and  at  about  one-third  from  its  posterior  extremity, 
is  the  parietal  foramen,  which  transmits  a  vein  to  the  superior  longitudinal 
sinus.  This  foramen  is  often  absent. 

Internal  surface. — The  internal  table  is  smooth ;  it  is  marked  by  nu- 
merous furrows,  which  lodge  the  ramifications  of  the  arteria  meningea 
media,  and  by  digital  fossae  which  correspond  with  the  convolutions  of 
the  brain.  Along  the  upper  border  is  part  of  a  shallow  groove,  completed 
by  the  opposite  parietal  bone,  which  serves  to  contain  the  superior  longitu- 
dinal sinus.  Some  slight  pits  are  also  observable  near  this  groove,  which 
lodge  the  glandule  Pacchioni. 

The  anterior  inferior  angle  is  thin  and  lengthened,  and  articulates  with 
the  greater  wing  of  the  sphenoid  bone.  Upon  its  inner  surface  it  is 
deeply  channelled  by  a  groove  for  the  trunk  of  the  arteria  meningea 
media.  This  groove  is  frequently  converted  into  a  canal.  The  posterior 

*  The  external  surface  of  the  left  parietal  bone.  1.  The  superior  or  sagittal  border. 
2.  The  inferior  or  squamous  border.  3.  The  anterior  or  coronal  border.  4.  The  poste- 
rior or  lambdoidal  border.  5.  The  temporal  ridge ;  the  figure  is  situated  immediately 
in  front  of  the  parietal  eminence.  6.  The  parietal  foramen,  unusually  large  in  the  bone 
from  which  this  figure  was  drawn.  7.  The  anterior  inferior  angle.  8.  The  posterior 
inferior  angle. 


62 


FRONTAL    BONE. 


Fig.  25* 


inferior  angle  is  thick,  and  presents 
a  broad  and  shallow  groove  for  the 
lateral  sinus. 

Development. — By  a  single  centre. 
Ossification  commences  at  the  parie- 
tal eminence  at  the  same  time  with 
the  bodies  of  the  vertebrae. 

Articulations.  —  With  five  bones ; 
with  the  opposite  parietal  bone,  the 
occipital,  frontal,  temporal,  and  sphe- 
noid. 

Attachment  of  Muscles.  —  To  one 
only, — the  temporal.  The  occipito- 
frontalis  glides  over  its  upper  sur- 
face. 


FRONTAL  BONE. — The  frontal  bone  bears  some  resemblance  in  form  to 
the  under  valve  of  a  scallop  shell.  It  is  situated  at  the  anterior  part  of  the 
cranium,  forming  the  forehead,  and  assists  in  the  construction  of  the  roof 
of  the  orbits  and  nose.  Hence  it  is  divisible  into  a  superior  or  frontal 
portion,  and  an  inferior  or  orbito-nasal  portion.  Each  of  these  portions 
presents  for  examination  an  external  and  internal  surface,  borders,  and 
processes. 

External  surface. — At  about  the  middle  of  each  lateral  half  of  the  fron- 
tal portion  is  a  projection,  the  frontal  eminence.  Below  these  points  are 
the  super  ciliary  ridges,  large  towards  their  inner  termination,  and  becoming 
gradually  smaller  as  they  arch  outwards :  they  support  the  eyebrows. 
Beneath  the  superciliary  ridges  are  the  sharp  and  prominent  arches  which 
form  the  upper  margin  of  the  orbits,  the  supra-orbital  ridges.  Externally 
the  supra-orbital  ridge  terminates  in  the  external  angular  process,  and 
internally  in  the  internal  angular  process ;  at  the  inner  third  of  this  ridge 
is  a  notch,  sometimes  converted  into  a  foramen,  the  supra-orbital  notch, 
which  gives  passage  to  the  supra-orbital  artery,  veins,  and  nerve.  Be- 
tween the  two  superciliary  ridges  is  a  rough  projection,  the  nasal  tuberosi- 
ty ;  this  portion  of  the  bone  denotes  by  its  prominence  the  situation  of  the 
frontal  sinuses.  Extending  upwards  and  backwards  from  the  external 
angular  process  is  a  sharp  ridge,  the  commencement  of  the  temporal  ridge, 
and  beneath  this  a  depressed  surface  that  forms  part  of  the  temporal  fossa. 

The  orbito-nasal  portion  of  the  bone  consists  of  two  thin  processes,  the 
orbital  plates,  which  form  the  roof  of  the  orbits,  and  of  an  intervening 
notch  which  lodges  the  ethmoid  bone,  and  is  called  the  ethmoidal  fissure. 
The  edges  of  the  ethmoidal  fissure  are  hollowed  into  cavities,  which,  by 
their  union  with  the  ethmoid  bone,  complete  the  ethmoidal  cells:  and, 
crossing  these  edges  transversely,  are  two  small  grooves,  sometimes  canals, 
which  open  into  the  orbit  by  the  anterior  and  posterior  ethmoidal  foramina. 
At  the  anterior  termination  of  these  edges  are  the  irregular  openings  which 

*  The  internal  surface  of  the  left  parietal  bone.  1.  The  superior  or  sagittal  border. 
2  The  inferior,  or  squamous  border.  3.  The  anterior,  or  coronal  border.  4.  The  poste- 
rior, or  lambdoidal  border.  5.  Part  of  the  groove  for  the  superior  longitudinal  sinus. 
6.  The  internal  termination  of  the  parietal  foramen.  7.  The  anterior  inferior  angle  of 
the  bone,  on  which  is  seen  the  groove  for  the  trunk  of  the  arteria  meningea  media.  8 
The  posterior  inferior  angle,  upon  which  is  seen  a  portion  of  the  groove  for  the  latera. 
•irus. 


FRONTAL    BONE. 


63 


Fig.  26 .« 


lead  into  the  frontal  sinuses ;  and  between  the  two  internal  angular  pro- 
cesses, is  a  rough  excavation  which  receives  the  nasal  bones,  and  a  pro- 
jecting process,  the  nasal  spine.  Upon  each  orbital  plate,  immediately 
beneath  the  external  angular  process,  is  a  shallow  depression  which  lodges 
the  lachrymal  gland ;  and  beneath  the 
internal  angular  process  a  small  pit, 
sometimes  a  tubercle,  to  which  the 
cartilaginous  pulley  of  the  superior 
oblique  muscle  is  attached. 

Internal  Surface. — Along  the  mid- 
dle line  of  this  surface  is  a  grooved 
ridge,  the  edges  of  the  ridge  giving 
attachment  to  the  falx  cerebri  and  the 
groove  lodging  the  superior  longitu- 
dinal sinus.  At  the  commencement 
of  the  ridge  is  an  opening,  sometimes 
completed  by  the  ethmoid  bone,  the 
foramen  caecum.  This  opening  lodges 
a  process  of  the  dura  mater,  and  oc- 
casionally gives  passage  to  a  small 
vein  which  communicates  with  the 
nasal  veins.  On  each  side  of  the  vertical  ridge  are  some  slight  depres- 
sions which  lodge  the  glandulae  Pacchioni,  and  on  the  orbital  plates  a 
number  of  irregular  pits  called  digital  fossa,  which  correspond  with  the 
convolutions  of  the  anterior  lobes  of  the  cerebrum.  The  superior  border 
is  thick  and  strongly  serrated,  bevelled 
at  the  expense  of  the  internal  table  in 
the  middle,  where  it  rests  upon  the 
junction  of  the  two  parietal,  and  at  the 
expense  of  the  external  table  on  each 
side  where  it  receives  the  lateral  pres- 
sure of  those  bones.  The  inferior  bor- 
der is  thin,  irregular,  and  squamous, 
and  articulates  with  the  sphenoid 
bone. 

Development. — By  two  centres,  one 
for  each  lateral  half.  Ossification  be- 
gins in  the  orbital  arches,  somewhat 
before  the  vertebrae.  The  two  pieces 
are  separate  at  birth,  and  unite  by  su- 
ture during  the  first  year,  the  su- 
ture sometimes  remaining  permanent 

*  The  external  surface  of  the  frontal  bone.  1.  The  situation  of  the  frontal  eminence 
of  the  right  side.  2.  The  superciliary  ridge.  3.  The  supra-orbital  ridge.  4.  The  ex 
ternal  angular  process.  5.  The  internal  angular  process.  6.  The  supra-orbital  notch 
for  the  transmission  of  the  supra-orbital  nerve  and  artery;  in  the  figure  it  is  almost 
converted  into  a  foramen  by  a  small  spiculum  of  bone.  7.  The  nasal  tuberosity;  the 
swelling  around  this  point  denotes  the  situation  of  the  frontal  sinuses.  8.  The  temporal 
ridge,  commencing  from  the  external  angular  process  (4).  The  depression  in  vhieu 
the  figure  8  is  situated  is  a  part  of  the  temporal  fossa.  9.  The  nasal  spine. 

j-  The  internal  surface  of  the  frontal  bone ;  the  bone  is  raised  in  such  a  manner  as  to 
ehow  the  orbito-nasal  portion.  1.  The  grooved  ridge  for  the  lodgment  of  the  superior 
longitudinal  sinus  and  attachment  of  the  falx.  2.  The  foramen  csecuin.  3.  The  superior 


Fig.  27.f 


64 


TEMPORAL    BONE. 


Fig.  28. 


through  life.  The  frontal  sinuses  make  their  appearance  during  the  fuV 
year,  and  increase  in  size  until  old  age. 

Articulations. — With  twelve  bones  :  the  two  parietal,  the  sphenoid, 
ethmoid,  two  nasal,  two  superior  maxillary,  two  lachrymal,  and  two 
malar. 

Attachment  of  Muscles. — To  two  pairs:  corrugator  supercilii,  and  tem- 
poral. 

TEMPORAL  BONE. — The  temporal  bone  is  situated  at  the  side  and  base 

of  the  skull,  and  is  divisible  into  a  squamous,  mastoid,  and  petrous  portion. 

The  Squamous  portion,  forming  the  anterior  part  of  the  bone,  is  thin, 

translucent,   and   contains  no   diploe.     Upon   its  external  surface  it  is 

smooth,  to  give  attachment  to  the  fleshy  fibres  of  the  temporal  muscle, 

and  has  projecting  from  it  an  arched 
and  lengthened  process,  the  zygoma. 
Near  the  commencement  of  the  zygo- 
ma, upon  its  lower  border,  is  a  projec- 
tion called  the  tubercle,  to  which  is  at- 
tached the  external  lateral  ligament  of 
the  lower  jaw,  and  continued  horizon- 
tally inwards  from  the  tubercle,  a 
rounded  eminence,  the  eminentia  arti- 
culnris.  .The  process  of  bone  which 
is  continued  from  the  tubercle  of  the 
zygoma  into  the  eminentia  articularis 
is  the  inferior  root  of  the  zygoma.  The 
superior  root  is  continued  upwards 
from  the  upper  border  of  the  zygoma, 
and  forms  the  posterior  part  of  the  temporal  ridge,  serving  by  its  projec- 
tion to  mark  the  division  of  the  squamous  from  the  mastoid  portion  of  the 
bone ;  and  the  middle  root  is  continued  directly  backwards,  and  termi- 
nates abruptly  at  a  narrow  fissure,  the  fissura  Glaseri.  The  internal  sur- 
face of  the  squamous  portion  is  marked  by  several  shallow  fossa,  which 
correspond  with  the  convolutions  of  the  cerebrum,  and  by  a  furrow  for 

or  coronal  border  of  the  bone;  the  figure  is  situated  near  that  part  which  is  bevelled  at 
the  expense  of  the  internal  table.  4.  The  inferior  border  of  the  bone.  5.  The  orbital 
plate  of  the  left  side.  6.  The  cellular  border  of  the  ethtnoidal  fissure.  The  foramen, 
caecum  (2)  is  seen  through  the  ethmoidal  fissure.  7.  The  anterior  and  posterior  eth- 
inoidal  foramina ;  the  anterior  is  seen  leading  into  its  canal.  8.  The  nasal  spine.  9.  The 
depression  within  the  external  angular  process  (12)  for  the  lachrymal  gland.  10.  The 
depression  for  the  pulley  of  the  superior  oblique  muscle  of  the  eye,  immediately  to 
the  left  of  this  number  is  the  supra-orbital  notch,  and  to  its  right  the  internal  angular 
process.  11.  The  opening  leading  into  the  frontal  sinuses:  the  leading  line  crosses  the 
internal  angular  process.  12.  The  external  angular  process.  The  corresponding  parts 
are  seen  on  the  other  side  of  the  figure. 

*  The  external  surface  of  the  temporal  bone  of  the  left  side.  1.  The  squamous  por- 
tion. 2.  The  mastoid  portion.  3.  The  extremity  of  the  petrous  portion.  4.  The  zy- 
goma. 5.  Indicates  the  tubercle  of  the  zygoma,  and  at  the  same  time  its  anterior  root 
turning  inwards  to  form  the  eminentia  articularis.  6.  The  superior  root  of  the  zygoma, 
forming  the  posterior  part  of  the  temporal  ridge.  7.  The  middle  root  of  the  zygoma, 
terminating  abruptly  at  the  glenoid  fissure.  8.  The  mastoid  foramen.  9.  The  meatus 
auditorius  externus,  surrounded  by  the  processus  auditorius.  10.  The  digastric  fossa, 
situated  immediately  to  the  inner  side  of  (2)  the  mastoid  process.  11.  The  styloid 
prccess.  12.  The  vaginal  process.  13.  The  glenoid  or  Glaserian  fissure;  the  leading 
line  from  this  number  crosses  the  rough  posterior  portion  of  the  glenoid  fossa.  14.  The 
•yuening  and  part  of  the  groove  for  the  Eustachian  tube. 


TEMPORAL    BOIS'E.  65 

the  posterior  branch  of  the  arteria  meningea  media.  The  superior^  or 
squamous  border,  is  very  thin,  and  bevelled  at  the  expense  of  the  inner 
surface,  so  as  to  overlap  the  lower  and  arched  border  of  the  parietal  bone. 
The  inferior  border  is  thick,  and  dentated  to  articulate  with  the  spinous 
process  of  the  sphenoid  bone. 

The  Mastoid  portion  forms  the  posterior  part  of  the  bone ;  it  is  thick, 
and  hollowed  between  its  tables  into  a  loose  and  cellular  diploe.  Upon 
its  external  surface  it  is  rough  for  the  attachment  of  muscles,  and  contrasts 
strongly  with  the  smooth  and  polished-like  surface  of  the  squamous  por- 
tion :  every  part  of  this  surface  is  pierced  by  small  foramina,  which  give 
passage  to  minute  arteries  and  veins ;  one  of  these  openings,  oblique  in 
its  direction,  of  large  size,  and  situated  near  the  posterior  border  of  the 
bone,  the  mastoid  foramen,  transmits  a  vein  to  the  lateral  sinus.  This 
foramen  is  not  unfrequently  situated  in  the  occipital  bone.  The  inferior 
part  of  this  portion  is  round  and  expanded,  the  mastoid  process,  and  ex- 
cavated in  its  interior  into  numerous  cells,  which  form  a  part  of  the  organ 
of  hearing.  In  front  of  the  mastoid  process,  and  between  the  superior 
and  middle  roots  of  the  zygoma,  is  the  large  oval  opening  of  the  meatus 
auditorius  externus,  surrounded  by  a  rough  lip,  the  processus  auditonus. 
Directly  to  the  inner  side  of,  and  partly  concealed  by  the  mastoid  process, 
is  a  deep  groove,  the  digastric  fossa  ;  and  a  little  more  internally  the  oc- 
cipital groove,  which  lodges  the  occipital  artery.  Upon  its  internal  sur- 
face the  mastoid  portion  presents  a  broad  and  shallow  groove  (fossa  sig- 
moidea)  for  the  lateral  sinus,  and  terminating  in  this  groove  the  internal 
opening  of  the  mastoid  foramen.  The  superior  border  of  the  mastoid  por- 
tion is  dentated ;  and  its  posterior  border,  thick  and  less  serrated,  articu- 
lates \vith  the  inferior  border  of  the-occipital  bone. 

The  meatus  auditonus  externus  is  a  slightly  curved  canal,  somewhat 
more  than  half  an  inch  in  length,  longer  along  its  lower  than  its  upper 
wall,  and  directed  obliquely  inwards  and  forwards.  The  canal  is  narrower 
at  the  middle  than  at  each  extremity,  is  broadest  in  its  horizontal  diameter, 
and  terminates  upon  the  outer  wall  of  the  tympanum  by  an  abrupt  oval 
border.  Within  the  margin  of  this  border  is  a  groove  for  the  insertion  of 
the  membrana  tympani. 

The  Petrous  portion  of  the  temporal  bone  is  named  from  its  extreme 
hardness  and  density.  It  is  a  three-sided  pyramid,  projecting  horizontally 
forwards  into  the  base  of  the  skull,  the  base  being  applied  against  the  in- 
ternal surface  of  the  squamous  and  mastoid  portions,  and  the  apex  being 
received  into  the  triangular  interval  between  the  spinous  process  of  the 
sphenoid  and  the  basilar  process  of  the  occipital  bone.  For  convenience 
of  description  it  is  divisible  into  three  surfaces — anterior,  posterior,  and 
basilar ;  and  three  borders — superior,  anterior,  and  posterior. 

Surfaces. — The  anterior  surface,  forming  the  posterior  boundary  of  the 
middle  fossa  of  the  interior  of  the  base  of  the  skull,  presents  for  exami- 
nation from  base  to  apex,  first,  an  eminence  caused  by  the  projection  of  the 
perpendicular  semicircular  canal ;  next,  a  groove  leading  to  an  irregular 
oblique  opening,  the  hiatus  Fallopii,  for  the  transmission  of  the  petrosal 
branch  of  the  Vidian  nerve;  thirdly,  another  and  smaller  oblique  Tcranien. 
immediately  beneath  the  preceding,  for  the  passage  of  the  nervus  petros^ 
superficial  minor,  a  branch  of  Jacobson's  nerve ;  and,  lastly,  a  large 
foramen  near  the  apex  of  the  bone,  the  termination  of  the  carotid 
canal. 

6*  E 


66 


TEMPORAL    BONE. 


Fig.  29.* 


The  posterior  surface  forms  the  front  boundary  of  the  posterior  fossa  of 
the  base  of  the  skull ;  near  its  middle  is  the  oblique  entrance  of  the  meatus 

auditorius  interims.  Above  the  meatus 
auditorius  internus  is  a  small  oblique  fis- 
sure, and  a  minute  foramen  ;  the  former 
lodges  a  process  of  the  dura  mater,  and 
the  foramen  gives  passage  to  a  small  vein. 
Further  outwards,  towards  the  mastoid 
portion  of  the  bone,  is  a  small  slit, 
almost  hidden  by  a  thin  plate  of  bone  ; 
this  is  the  aqu&ductus  vestibuli,  and 
transmits  a  small  artery  and  vein  of  the 
vestibule  and  a  process  of  dura  mater. 
Below  the  meatus,  and  partly  concealed 
by  the  margin  of  the  posterior  border  of 
the  bone,  is  the  aquceductus  cochlece, 
through  which  passes  a  vein  from  the  cochlea  to  the  internal  jugular  vein, 
and  a  process  of  dura  mater. 

The  meatus  auditorius  internus  is  about  one-third  of  an  inch  in  depth, 
and  pursues  a  slightly  oblique  course  in  relation  to  the  petrous  portion  of 

the  temporal  bone,  but  a  course  directly  out- 
wards in  relation  to  the  cranium.  At  the  bot- 
tom of  the  meatus,  and  upon  its  anterior  as- 
pect, is  a  reniform  fossa,  the  concave  border 
of  which  is  directed  towards  the  entrance  of 
the  meatus.  The  reniform  fossa  is  divided 
into  an  upper  and  lower  compartment  by  a 
sharp  ridge,  which  is  prolonged  for  some  dis- 
tance upon  the  anterior  wall  of  the  meatus, 
and  sometimes  as  far  as  its  aperture ;  in  either 
case  it  marks  the  situation  of  the  two  nerves, 
facial  and  auditory,  \vhich  constitute  the  se- 
venth pair,  and  enter  the  meatus.  Along  the  convexity  of  the  reniform 
fossa,  and  aromged  in  a  curved  line  from  above  downwards,  are  four  or 

*  The  left  temporal  bone,  seen  from  within.  1.  The  squamous  portion.  2.  The 
mastoid  por«xm.  The  number  is  placed,  immediately  above  the  inner  opening  of  the 
mastoid  foramen.  3.  The  petrous  portion.  4.  The  groove  for  the  posterior  branch  of 
the  artena  meningea  media.  5.  The  bevelled  edge  of  the  squamous  border  of  the  bone. 
6.  The  zygoma.  7.  The  digastric  fossa  immediately  internal  to  the  mastoid  process. 
8.  The  occipital  groove.  9.  The  groove  for  the  lateral  sinus.  10.  The  elevation  upon 
tne  anterior  surface  of  the  petrous  bone  marking  the  situation  of  the  perpendicular  semi- 
circular canal.  11.  The  opening  of  termination  of  the  carotid  canal.  12.  The  meatus 
auditorius  internus.  13.  A  dotted  line  leads  upwards  from  this  number  to  the  narrow 
fissure  which  lodges  a  process  of  the  dura  mater.  Another  line  leads  downwards  to 
the  sharp  edge  which  conceals  the  opening  of  the  aquseductus  cochleae,  •while  the  num- 
ber itself  is  situated  on  the  bony  lamina  which  overlies  the  opening  of  the  aquteductus 
vestibuli.  14.  The  styloid  process.  15.  The  stylo-mastoid  foramen.  10.  The  carotid 
foramen.  17.  The  jugular  process.  The  deep  excavation  to  the  left  of  this  process 
forms  part  of  the  jugular  fossa,  and  that  to  the  right  is  the  groove  for  the  eighth  pair  of 
nerves.  18.  The  notch  for  the  fifth  nerve  upon  the  upper  border  of  the  petrous  bone, 
hear  its  apex.  19.  The  extremity  of  the  petrous  bone  which  gives  origin  to  the  levator 
l.aiati  and  tensor  tympani  muscles. 

t-i.  The  reniform   fossa  of  the  meatus    auditorius   internus;    right  temporal   bone. 

The  ridge  dividing  the  reniform  fossa  into  two  compartments.  2.  The  opening  of 
tv  wjuffidttctua  Falk>pii.  The  openings  following  that  of  the  aquasductus  Fallopii  in 
u  curved  direction  require  no  reference.  3.  The  cluster  of  three  or  four  oblique 


TEMPORAL    BONE.  67 

five  openings,  the  two  upper  ones  being  the  largest,  and  occupying  (he 
superior  compartment  of  the  renifonn  fossa,  and  the  two  or  three  inl'erioi 
ones,  smaller  than  the  upper,  the  inferior  compartment.  Behind  the 
latter,  at  the  distance  of  a  line  and  a  half,  and  on  the  posterior  wall  of  the 
meatus,  is  a  cluster  of  three  or  four  oblique  openings,  two  of  which  are 
minute.  The  inferior  and  larger  compartment  of  the  reniform  fossa  pre- 
sents a  well-marked  spiral  groove,  which  commences  on  the  convex  border 
of  the  fossa,  immediately  below  the  line  of  openings  above  described,  and, 
sweeping  round  the  convexity  of  the  inferior  compartment,  and  becoming 
deeper  as  it  proceeds,  terminates  by  a  small  round  aperture  in  the  centre 
of  the  spire-  The  uppermost  of  the  openings  of  the  reniform  fossa  is  the 
aperture  of  the  aqugeductus  Fallopii,  and  gives  passage  to  the  facial  nerve. 
The  rest  are  cul  de  sacs,  pierced  at  the  bottom  by  a  number  of  minute 
foramina  for  the  passage  of  filaments  of  the  vestibular  nerve,  while  the 
cluster  of  three  openings  on  the  posterior  wall  of  the  meatus  are  intended 
for  single  filaments  of  the  same  nerve.  The  spiral  groove  corresponds 
with  the  base  of  the  cochlea,  and  being  pierced  by  a  number  of  minute 
foramina  for  filaments  of  the  cochlear  nerve,  is  named  tractus  spiralis 
foraminulentus.  The  opening  in  the  centre  of  the  spiral  impression  leads 
into  a  canal  which  occupies  the  central  axis  of  the  modiolus,  and  is  thence 
called  tubulus  centralis  modioli. 

The  basilar  surface  is  rough  and  irregular,  and  enters  into  the  formation 
of  the  under  surface  of  the  base  of  the  skull.  Projecting  downwards,  near 
its  middle,  is  a  long  sharp  spine,  the  styloid  process,  occasionally  connected 
with  the  bone  only  by  cartilage,  and  lost  during  maceration,  particularly 
in  the  young  subject.  At  the  base  of  this  process  is  a  rough  sheath-like 
ridge,  into  which  the  styloid  process  appears  implanted,  the  vaginal  pro- 
cess. In  front  of  the  vaginal  process  is  a  broad  triangular  depression,  the 
glenoid  fossa,  bounded  in  front  by  the  erninentia  articularis,  behind  by 
the  vaginal  process,  and  externally  by  the  rough  lip  of  the  processus  audi- 
torius. 

This  fossa  is  divided  transversely  by  the  glenoid  fissure  (fissura  Glaseri), 
which  lodges  the  extremity  of  the  processus  gracilis  of  the  malleus,  and 
transmits  the  laxatar. tympani  muscle,  chorda  tympani  nerve,  and  anterior 
tympanic  artery.  The  surface  of  the  fossa  in  front  of  this  fissure  is  smooth, 
to  articulate  with  the  condyle  of  the  lower  jaw ;  and  that  behind  the  fissure 
is  rough,  for  the  reception  of  a  part  of  the  parotid  gland.  At  the  extre- 
mity of  the  inner  angle  of  the  glenoid  fossa  is  the  foramen  of  the  Eusta- 
chian  tube ;  and  separated  from  it  by  a  thin  lamella  of  bone,  called  pro- 
cessus cochlea  riformis,  a  small  canal  for  the  transmission  of  the  tensor 
tympani  muscle.  Directly  behind,  and  at  the  root  of  the  styloid  process, 
is  the  stylo-mastoid  foramen,  the  opening. of  exit  of  the  facial  nerve,  and 
of  entrance  of  the  stylo-mastoid  artery.  Nearer  the  apex  of  the  bone  is  a 

openings  on  the  posterior  wall  of  the  meatus.  4.  The  spirally-grooved  base  of  the 
cochlea. 

B.  A  section  of  the  temporal  bone,  right  side,  showing  the  curved  direction  of  the 
meatus  auditorius  externus.  1.  The  edge  of  the  processus  auditorius.  «,.  The  groove 
into  which  the  membrana  tympani  is  inserted.  The  obliquity  of  the  line  from  2  to  3 
indicates  the  oblique  termination  of  the  meatus,  and  the  consequent  oblique  direction 
of  the  membrana  tympani.  4,  4.  The  cavity  of  the  tympanum.  5.  The  opening  of 
the  Eustachian  tube.  6.  Part  of  the  aquseductus  Fallopii.  7.  Part  of  the  carotiJ 
canal. 

c.  The  annulus  membrane  tympani  or  temporal  bone  cf  the  foetal  skull,  right  side. 


68  TEMPORAL    BONE. 

large  oval  opening,  the  carotid  foramen ,  the  commencement  of  the  caiotul 
canal,  which  lodges  the  internal  carotid  artery  and  the  carotid  plexus. 
And  between  the  stylo-mastoid  and  carotid  foramen,  in  the  posterior 
border,  is  an  irregular  excavation  forming  part  of  the  jugular  fossa  for  the 
commencement  of  the  internal  jugular  vein.  The  proportion  of  the  jugular 
fossa  formed  by  the  petrous  portion  of  the  temporal  bone  is  very  differen 
in  different  bones ;  but  in  all,  the  fossa  presents  a  vertical  ridge  on  it 
inner  side,  which  cuts  off  a  small  portion  from  the  rest.  The  upper  par 
of  this  ridge  forms  a  spinous  projection,  which  is  called  the  jugular  process 
the  groove  to  the  inner  side  of  the  ridge  lodges  the  eighth  pair  of  nerves, 
and  the  lower  part  of  the  ridge  is  the  septum  of  division  between  the  jugu- 
lar fossa  and  the  carotid  foramen.  Upon  this  portion  of  the  ridge  near  the 
posterior  margin  of  the  carotid  foramen  is  a  small  opening  leading  into  a 
canal,  which  transmits  the  tympanic  branch  (Jacobson's  nerve)  of  the 
glossopharyngeal  nerve.  Between  the  jugular  fossa  and  the  stylo-mastoid 
foramen  is  another  small  opening  leading  into  the  canal  for  the  passage  of 
the  auricular  branch  of  the  pneumogastric  nerve. 

Borders.  —  The  superior  border  is  sharp,  and  gives  attachment  to  the 
tentorium  cerebelli.  It  is  grooved  for  the  superior  petrosal  sinus,  and 
near  its  extremity  is  marked  by  a  smooth  notch  upon  which  reclines  the 
fifth  nerve. 

The  anterior  border  is  grooved  for  the  Eustachian  tube,  and  forms  the 
posterior  boundary  of  the  foramen  lacerum  basis  cranii ;  by  its  sharp 
extremity  it  gives  attachment  to  the  tensor  tympani  and  levator  palati 
muscles.  The  posterior  border  is  grooved  for  the  inferior  petrosal  sinus, 
and  excavated  for  the  jugular  fossa ;  it  forms  the  anterior  boundary  of  the 
foramen  lacerum  posterius. 

Development.  —  By  Jive  centres :  one  for  the  squamous  portion,  one  for 
the  mastoid  process,  one  for  the  petrous  portion,  one  for  the  auditory  pro- 
cess, which  in  the  foetus  is  a  mere  bony  ring,  incomplete  superiorly,  and 
serving  for  the  attachment  of  the  membrana  tympani,  annulus  membranes 
tympani ;  and  one  for  the  styloid  process.  Ossification  occurs  in  these 
pieces  in  the  following  order :  in  the  squamous  portion  immediately  aftei 
the  vertebrae,  then  in  the  petrous,  tympanic,  mastoid,  and  styloid.  The 
tympanic  ring  is  united  by  its  extremities  to  the  squamous  portion  during 
the  last  month  of  intra-uterine  life ;  the  squamous,  petrous,  and  mastoid 
portions  are  consolidated  during  the  first  year ;  and  the  styloid  some  years 
after  birth.  It  not  unfrequently  happens  that  the  latter  remains  perma- 
nently separate,  or  is  prolonged  by  a  series  of  pieces  to  the  os  hyoides, 
and  so  completes  the  hyoid  arch.  The  subsequent  changes  in  the  bone 
are  the  increase  of  size  of  the  glenoid  fossa,  the  growth  of  the  meatus" 
auditorius  externus,  the  levelling  of  the  surfaces  of  the  petrous  portion, 
and  the  development  of  mastoid  cells.  Traces  of  the  union  of  the  petrous 
with  the  squamous  portion  of  the  bone  are  usually  perceptible  in  the  adult. 

Articulations. — With  Jive  bones :  occipital,  parietal,  sphenoid,  inferior 
maxillary,  and  malar. 

Attachment  of  Muscles. — To  fourteen:  by  the  squamous  portion,  to  the 
temporal ;  by  the  zygoma,  to  the  masseter ;  by  the  mastoid  portion,  to 
the  occipito-frontalis,  splenius  capitis,  sterno-mastoid,  trachelo-mastoid, 
digastricus  and  retrahens  aurem ;  by  the  styloid  process,  to  the  stylo- 
rmaryngeus,  stylo-hyoideus,  stylo-glossus,  and  two  ligaments,  the  stylo- 


SPHENOID    BONE.  69 

hyoid  and  stylo-maxillary ;  and  by  the  petrous  portion,  to  the  levator 
palati,  tensor  tympani,  and  stapedius. 

SPHENOID  BONE.  —  The  sphenoid  (<rq>rtv,  a  wedge)  is  an  irregular  bone 
situated  at  the  base  of  the  skull,  wedged  between  the  other  bones  of  the 
cranium,  and  entering  into  the  formation  both  of  the  cranium  and  face.  It 
bears  some  resembjance,  in  form,  to  a  bat  with  its  wings  extended,  and  is 
divisible  into  body,  wings,  and  processes. 

The  body  forms  the  central  mass  of  the  bone,  from  which  the  wings  and 
processes  are  projected.  From  the  upper  and  anterior  part  of  the  body 
extend  on  each  side  two  small  triangular  plates  —  the  lesser  wings ;  from 
either  side  and  expanding  laterally  are  the  greater  wings ;  proceeding 
backwards  from  the  base  of  the  greater  wings,  the  spinous  processes,  and 
downwards,  the  pterygoid  processes. 

The  body  presents  for  examination  a  superior  or  cerebral  surface,  an 
antero-inferior  surface,  and  a  posterior  surface. 

Superior  Surface.  —  At  the  anterior  extremity  of  this  surface  is  a  small 
projecting  plate,  the  ethmoidal  spine,  and  spreading  out  on  either  side  the 
lesser  wings.  Behind  the  ethmoidal  spine  in  the  middle  line  is  a  rounded 
elevation,  the  olivary  process,  which  supports  the  commissure  of  the  optic 
nerves ;  and  on  either  side  of  the  posterior  margin  of  this  process  is  a 
tubercle,  the  middle  clinoid  process.  Passing  outwards  and  forwards  from 
the  olivary  process,  are  the  optic  foramina,  which  transmit  the  optic  nerves 
and  ophthalmic  arteries.  Behind  the  optic  foramina  are  two  sharp  tuber- 
cles, the  anterior  clinoid  processes,  which  are  the  inner  terminations  of  the 
lesser  wings.  Beneath  these  processes,  on  the  sides  of  the  olivary  process, 
are  two  depressions*  for  the  last  turn  of  the  internal  carotid  arteries.  Be- 
hind the  olivary  process  is  the  sella  turcica  (ephippium),  the  deep  fossa 
which  lodges  the  pituitary  gland  and  circular  sinus  ;  behind  and  somewhat 
overhanging  the  sella  turcica,  is  a  broad  rough  plate  (dorsum  ephippii) 
bounded  at  each  angle  by  a  tubercle,  the  posterior  clinoid  processes  ;  and 
behind  this  plate  an  inclining  surface  (clivus  Blumenbachii),  which  is  con- 
tinuous with  the  basilar  process  of  the  occipital  bone.  On  either  side  of 
the  sella  turcica  is  a  broad 

groove  (carotid)  which  lodges  *lg-  3LT 

the  internal  carotid  artery,  the 
cavernous  sinus,  and  the  orbi- 
tal nerves.  Immediately  exter- 
nal to  this  groove,  at  the  junc- 
tion of  the  greater  wings  with 
the  body,  are  four  foramina : 
the  first  is  a  broad  interval, 
the  sphenoidal  fissure,  which 
separates  the  greater  and  lesser 
wings,  and  transmits  the  third, 

*  These  depressions  are  occasionally,  as  in  a  skull  before  me,  converted  into  fora 
mina  by  the  extension  of  a  short  bony  pillar  from  the  middle  to  the  anterior  clinoid 
process. 

|  The  superior  or  cerebral  surface  of  the  sphenoid  bone.  1.  The  processus  divans. 
2.  The  ethmoidal  spine.  3.  The  lesser  wing  of  the  left  side.  4.  The  cerebral  surface 
of  the  greater  wing  of  the  same  side.  5.  The  spinous  process.  6.  The  extremity  of 
the  pterygoid  process  of  the  same  side,  projecting  downwards  from  the  under  stirfao'e 
of  the  body  of  the  bone.  7  The  foramen  opticum.  8.  The  anterior  clynoid  process. 


70 


SPHENOID   BONE. 


fourth,  the  three  branches  of  the  ophthalmic  division  of  the  fifth  and  the 
sixth  nerves,  and  the  ophthalmic  vein.  Behind  and  beneath  this  fissure 
is  the  foramen  rotundum  for  the  superior  maxillary  nerve  ;  and  still  farther 
back,  in  the  base  of  the  spinous  process,  the  foramen  ovale  for  the  inferior 
maxillary  nerve,  arteria  meningea  parva,  and  nervus  petrosus  superficialis 
minor.  Behind  the  foramen  ovale,  near  the  apex  of  the  spinous  process, 
is  the  foramen  spinosum  for  the  arteria  meningea  medea. 

Upon  the  antero-inferior  surface  of  the  sphenoid  is  a  long  flattened 
spine  or  crest,  the  superior  part  of  which,  crista  sphenoidalis,  articulates 
with  the  central  lamella  of  the  ethmoid,  while  the  inferior  part  longer  and 
sharper,  the  rostrum  sphenoidale,  is  intended  to  be  inserted  into  the  sheath 
formed  by  the  upper  border  of  the  vomer.  On  either  side  of  the  crista 
sphenoidalis  is  an  irregular  opening  leading  into  the  sphenoidal  cells. 
The  sphenoidal  cells,  which  are  absent  in  the  young  subject,  are  divided 
by  a  median  septum  which  is  continuous  with  the  crista,  and  are  partially 
closed  by  two  thin  plates  of  bone  (frequently  broken  away),  the  sphenoidal 
spongy  bones.  On  each  side  of  the  sphenoidal  cells  are  the  outlets  of  the 

optic  foramina,  sphenoidal  fissures, 
and  foramina  rotunda,  the  lesser 
and  greater  wings  ;  and,  below,  the 
pterygoid  processes.  Upon  the  un- 
der surface  of  the  body  are  two  thin 
plates  of  bone  (processus  vaginales) 
proceeding  from  the  base  of  the 
pterygoid  process  at  each  side,  and 
intended  for  articulation  with  the 
borders  of  the  vomer.  On  each  of 
these  plates,  close  to  the  root  of 
the  pterygoid  process,  is  a  groove 
(sometimes  a  complete  canal)  converted  into  a  canal  by  the  palate  bone, 
the  pterygo-palatine  canal  for  the  pterygo-palatine  artery ;  and  traversing 
the  roots  of  the  pterygoid  processes  at  their  union  with  the  body  of  the 

9.  The  groove  by  the  side  of  the  sella  turcica;  for  lodging  the  internal  carotid  artery, 
cavernous  plexus,  cavernous  sinus,  and  orbital  nerves.  10.  The  sella  turcica;  the  two 
tubercles  in  front  of  the  figure  are  the  middle  clinoid  processes.  11.  The  posterior 
boundary  of  the  sella  turcica;  its  projecting  angles  are  the  posterior  clinoid  processes. 
12.  The  basilar  portion  of  the  bone.  13.  Part  of  the  sphenoidal  fissure.  14.  The  fora- 
men rotundum.  15.  The  foramen  ovale.  16.  The  foramen  spinosum.  17.  The  angu- 
lar interval  which  receives  the  apex  of  the  petrous  portion  of  the  temporal  bone.  The 
posterior  extremity  of  the  Vidian  canal  terminates  at  this  angle.  18.  The  spine  of  the 
spinous  process  ;  it  affords  attachment  to  the  internal  lateral  ligament  of  the  lower  jaw. 
19.  The  border  of  the  greater  wing  and  spinous  process,  which  articulates  with  the 
anterior  part  of  the  squamous  portion  of  the  temporal  bone.  20.  The  internal  border 
of  the  spinous  process,  which  assists  in  the  formation  of  the  foramen  lacerum  basis 
cranii.  21.  That  portion  of  the  greater  ala  which  articulates  with  the  anterior  inferior 
angle  of  the  parietal  bone.  22.  The  portion  of  the  greater  ala  which  articulates  with 
the  orbital  process  of  the  frontal  bone. 

*  The  antero-inferior  view  of  the  sphenoid  bone.  1.  The  ethmoid  spine.  2.  Tho 
rostrum.  3.  The  sphenoidal  spongy  bone,  partly  closing  the  left  opening  of  the  sphe- 
noidal cells.  4.  The  lesser  wing.  5.  The  foramen  opticum,  piercing  the  base  of  the 
lesser  wing.  6.  The  sphenoidal  fissure.  7.  The  foramen  rotundum.  8.  The  orbital 
surface  of  the  greater  wing.  9.  Its  temporal  surface.  10.  The  pterygoid  ridge.  11. 
The  pterygo-palatine  canal.  12.  The  foramen  of  entrance  to  the  Vidian  canal.  13. 
The  internal  pterygoid  plate.  14.  The  hamular  process.  15.  The  external  pterygoid 
plate.  16  The  foramen  spinosum  17.  The  foramen  ovale.  IS.  The  extremity  ot 
tbe  soinons  process  of  the  sphenoid. 


SPHENOID    BONE.  71 

bone,  are  the  two  pterygoid  or  Vidian  canals,  which  give  passage  to  the 
Vidian  nerve  and  artery  at  each  side. 

The  posterior  surface  is  flat  and  rough,  and  articulates  with  the  basilar 
process  of  the  occipital  bone.  In  the  adult  this  union  is  usually  completed 
by  bone;  from  which  circumstance  the  sphenoid,  in  conjunction  with  the 
occipital,  is  described  by  Soemmering  and  Meckel  as  a  single  bone,  under 
the  name  of  spheno-occipital.  The  posterior  surface  is  continuous  on 
each  side  with  the  spinous  process,  and  at  the  angle  of  union  is  the  termi- 
nation of  the  Vidian  canal. 

The  lesser  wings  (processes  of  Ingrassias)  are  thin  and  triangular,  tho 
base  being  attached  to  the  upper  and  anterior  part  of  the  body  of  the  sphe- 
noid, and  the  apex  extended  outwards,  and  terminating  in  an  acute  point. 
The  anterior  border  is  irregularly  serrated,  the  posterior  being  free  and 
rounded,  and  received  into  the  fissure  of  Sylvius  of  the  cerebrum.  The 
inner  extremily  of  this  border  is  the  anterior  clinoid  process,  which  is  sup- 
ported by  a  short  pillar  of  bone,  giving  attachment  to  a  part  of  the  com- 
mon tendon  of  the  muscles  of  the  orbit.  The  lesser  wing  forms  the  pos- 
terior part  of  the  roof  of  the  orbit,  and  its  base  is  traversed  by  the  optic 
foramen. 

The  greater  wings  present  three  surfaces ;  a  superior  or  cerebral,  which 
forms  part  of  the  middle  fossa  of  the  base  of  the  skull,  an  anterior  surface 
which  assists  in  forming  the  outer  wall  of  the  orbit,  and  an  external  sur- 
face divided  into  two  parts  by  the  pterygoid  ridge.  The  superior  part  of 
the  external  surface  enters  into  the  formation  of  the  temporal  fossa,  and  the 
inferior  portion  forms  part  of  the  zygomatic  fossa.  The  pterygoid  ridge, 
dividing  the  two,  gives  attachment  to  the  upper  origin  of  the  pterygoideus 
externus  muscle. 

The  spinous  processes  project  backwards  at  each  side  from  the  base  of 
the  greater  wings  of  the  sphenoid,  and  are  received  into  the  angular  inter- 
vals between  the  squamous  and  petrous  portions  of  the  temporal  bones. 
Piercing  the  base  of  each  process  is  a  large  oval  opening,  the  foramen 
ovale;  nearer  its  apex  a  smaller  opening,  the  foramen  spinosum;  and 
extending  downwards  from  the  apex  a  short  spine,  which  gives  attachment 
to  the  internal  lateral  ligament  of  the  lower  jaw  and  to  the  laxator  tym- 
pani  muscle.  The  external  border  of  the  spinous  process  is  rough,  to 
articulate  with  the  lower  border  of  the  squamous  portion  of  the  temporal 
bone ;  the  internal  forms  the  anterior  boundary  of  the  foramen  lacerum 
basis  cranii,  and  is  somewhat  grooved  for  the  reception  of  the  Eustachian 
tube. 

The  pterygoid  processes  descend  perpendicularly  from  the  base  of  the 
greater  wings,  and  form  in  the  articulated  skull  the  lateral  boundaries  of 
the  posterior  nares.  Each  process  consists  of  an  external  and  internal 
plate,  and  an  anterior  surface.  The  external  plate  is  broad  and  thin, 
giving  attachment,  by  its  external  surface,  to  the  external  pterygoid 
muscle,  and  by  its  internal  surface  to  the  internal  pterygoid.  This  plate 
is  sometimes  pierced  by  a  foramen,  which  is  not  unfrequently  formed  by 
a  process  of  communication  passing  between  it  and  the  spinous  process. 
The  internal  pterygoid  plate  is  long  and  narrow,  and  terminated  at  its 
extremity  by  a  curved  hook,  the  hamular  process,  around  which  plays  the 
tendon  of  the  tensor  palati  muscle.  At  the  base  of  the  internal  pterygoid 
plate  is  a  small  oblong  depression,  the  scaphoid  fossa,  from  which  arises 
the  circumflexus  or  tensor  palati  muscle.  The  interval  between  the  two 


72  ETHMOID    BONE. 

pterygoid  plates  is  the  pterygoid  fossa ;  and  the  two  plates  are  separated 
inferiorly  by  an  angular  notch  (palatine),  which  receives  the  tuberosity,  or 
pterygoid  process,  of  the  palate  bone.  The  anterior  surface  of  the  ptery- 
goid process  is  broad  near  its  base,  and  supports  Meckel's  ganglion.  The 
base  of  the  process  is  pierced  by  the  Vidian  canal. 

Development. — By  twelve  centres :  four  for  the  body,  viz.  two  for  its 
anterior  (spheno-orbital),  and  two  for  its  posterior  part  (spheno-temporal); 
four  for  the  four  wings ;  two  for  the  internal  pterygoid  plates,  and  two  for 
the  sphenoidal  spongy  bones.  Ossification  commences  in  the  various 
pieces  of  the  sphenoid  in  the  following  order : — greater  alse,  at  about  the 
same  time  with  the  other  bones  of  the  cranium ;  lesser  alse  and  posterior 
body,  at  the  end  of  the  second  month ;  anterior  body  at  the  end  of  the 
third  ;  internal  pterygoid  plate  and  spongy  bones,  between  the  period  of 
birth  and  the  second  year.  Osseous  union  occurs  first  between  the  centres 
for  the  posterior  body,  and  at  about  the  same  time  between  each  centre  of 
the  anterior  body  and  its  corresponding  (lesser)  ala ;  the  third  union  takes 
place  between  the  internal  pteiygoid  plate  and  the  greater  ala ;  the  fourth 
between  the  two  centres  of  the  anterior  body,  and  at  the  same  time  be- 
tween the  anterior  and  posterior  body.  This  is  the  state  of  union  at  birth, 
the  bone  consisting  of  five  centres,  one  being  the  body  and  lesser  alse ; 
one,  on  each  side,  the  great  ala  and  internal  pterygoid  plate;  and  the 
remaining  two  the  sphenoidal  spongy  bones.  The  greater  alse  unite  writh 
the  body  during  the  first  year ;  the  spongy  bones  after  puberty ;  and  the 
oody  of  the  sphenoid  \vith  the  basilar  process  of  the  occipital  bone  be- 
tween eighteen  and  twenty-five. 

Articulations.  — With  twelve  bones  ;  that  is,  with  all  the  bones  of  the 
head,  and  five  of  the  face,  viz.  the  two  malar,  two  palate,  and  the  vomer. 

Attachment  of  Muscles. — To  twelve  pairs :  temporal,  external  ptery- 
goid, internal  pterygoid,  superior  constrictor,  tensor  palati,  laxator  tym- 
pani,  levator  palpebree,  obliquus  superior,  superior  rectus,  internal  rectus, 
inferior  rectus,  and  external  rectus. 

ETHMOID  BONE. — The  ethmoid  (r^o.c,  a  sieve)  is  a  square- shaped  cel- 
lular bone,  situated  between  the  two  orbits,  at  the  root  of  the  nose,  and 
perforated  upon  its  upper  surface  by  a  number  of  small  openings,  from 
which  peculiarity  it  has  received  its  name.  It  consists  of  a  perpendicular 
lamella  and  two  lateral  masses. 

The  perpendicular  lamella  is  a  thin  central  plate,  which  articulates  with 
the  vomer  and  cartilage  of  the  septum,  and  assists  in  forming  the  septum 
of  the  nose.  It  is  surmounted  superiorly  by  a  thick  and  strong  process, 
the  crista  galli,  which  projects  into  the  cavity  of  the  skull,  and  gives 
attachment  to  the  falx  cerebri.  From  the  base  of  the  anterior  border  of 
this  process  there  project  forward  two  small  plates,  alar  processes,  which 
are  received  into  corresponding  depressions  in  the  frontal  bone,  and  often 
complete  posteriorly  the  foramen  caecum.  On  each  side  of  the  crista  galli, 
upon  the  upper  surface  of  the  bone,  is  a  thin  and  grooved  plate  perforated 
by  a  number  of  small  openings,  the  cribriform  lamella, \vhich  supports  thf 
bulb  of  the  olfactory  nerve,  and  gives  passage  to  its  filaments,  and  to  the 
nasal  branch  of  the  ophthalmia  nerve.  In  the  middle  of  the  groove  of 
(his  lamella  the  foramina  pierce  the  bone  completely,  but  at  either  side 
they  are  the  apertures  of  canals,  which  run  for  some  distance  in  the 
substance  of  the  central  lamella,  inner  wall  of  the  lateral  mass,  and  spongy 


ETHMOID   BONE.  73 

bones.     The  opening  for  the  nasal  nerve  is  a  nar-  Fig.  33.» 

row  slit  in  the  anterior  part  of  the  cribriform  la- 
mella, close  to  the  crista  galli.  The  cribriform 
lamella  serves  to  connect  the  lateral  masses  with 
.the  perpendicular  plate. 

The  lateral  masses  (labyrinthi)  are  divisible 
into  an  internal  and  external  surface,  and  four 
borders,  superior,  inferior,  anterior,  and  posterior. 
The  internal  surface  is  rough  and  slightly  convex, 
and  forms  the  external  boundary  of  the  upper  part 
of  the  nasal  fossae.  Towards  the  posterior  border 
of  this  surface  is  a  narrow  horizontal  fissure,  the 
superior  meatus  of  the  nose,  the  upper  margin  of  which  is  thin,  and 
somewhat  curled  inwards ;  hence  it  is  named  the  superior  turbinated  bone 
(concha  superior).  Below  the  meatus  is  the  convex  surface  of  another 
thin  plate,  which  is  curled  outwards,  and  forms  the  lower  border  of  the 
mass,  the  middle  turbinated  bone  (concha  media).  The  external  surface 
is  quadrilateral  and  smooth,  hence  it  is  named  os  planum,  and,  from  its 
thinness,  lamina  papyracea ;  it  enters  into  the  formation  of  the  inner  wall 
of  the  orbit. 

The  superior  border  is  irregular  and  cellular,  the  cells  being  completed 
by  the  edges  of  the  ethmoidal  fissure  of  the  frontal  bone.  This  border  is 
crossed  by  two  grooves,  sometimes  complete  canals,  opening  into  the 
orbit  by  the  anterior  and  posterior  ethmoidal  foramina.  The  inferior  bor- 
der is  formed  internally  by  the  lower  border  of  the  middle  turbinated  bone, 
and  externally  by  a  concave  irregular  fossa,  the  upper  boundary  of  the 
middle  meatus.  The  anterior  border,  presents  a  number  of  incomplete 
cells,  which  are  closed  by  the  superior  maxillary  and  lachrymal  bone  ;  and 
the  posterior  border  is  regularly  cellular,  to  articulate  with  the  sphenoid 
and  palate  bones. 

The  lateral  masses  are  composed  of  cells,  which  are  divided  by  a  thin 
partition  into  anterior  and  posterior  ethmoidal  cells.  The  anterior,  the 
most  numerous,  communicate  with  the  frontal  sinuses,  and  open  by  means 
of  an  irregular  and  incomplete  tubular  canal,  the  infundibulum,  into  the 
middle  meatus.  The  posterior  c^lls,  fewer  in  number,  open,  into  the  su- 
perior meatus. 

Development. — By  three  centres :  one  for  each  lateral  mass,  and  one  for 
the  perpendicular  lamella.  Ossification  commences  in  the  lateral  masses 
at  about  the  beginning  of  the  fifth  month,  appearing  first  in  the  os  planum 
and  then  in  the  spongy  bones.  During  the  latter  half  of  the  first  year 
after  birth,  the  central  lamella  and  lamina  cribrosa  begin  to  ossify,  and  are 
united  to  the  lateral  masses  by  the  beginning  of  the  second  year.  The 
cells  of  the  ethmoid  are  developed  in  the  course  of  the  fourth  and  fifth  year. 

*  The  ethmoid  bone  seen  from  above  and  behind.  1.  The  central  lamella.  2,  2.  The 
lateral  masses  ;  the  numbers  are  placed  on  the  posterior  border  of  the  lateral  mass  at 
each  side.  3.  The  crista  galli  process.  4.  The  cribriform  plate  of  the  left  side,  pierced 
by  its  foramina.  5.  The  hollow  space  immediately  above  and  to  the  left  of  this  num- 
ber is  the  superior  meatus.  6.  The  superior  turbinated  bone.  7.  The  middle  turbinated 
bone  ;  the  numbers  5,  6,  7.  are  situated  upon  the  internal  surface  of  the  left  lateral  mass, 
near  its  posterior  part.  The  interval  between  these  parts  is  the  superior  meatus.  8.  The 
external  surface  of  the  lateral  mass,  or  os  planum.  9.  The  superior  or  frontal  border 
of  the  lateral  mass,  grooved  by  the  anterior  and  posterior  ethmoidal  canals.  lO.  Re/er» 
to  the  concavity  of  the  middle  turbinated  bone,  which  is  the  upper  boundary  of  iha 
middle  meatus. 


74  SUPERIOR  MAXILLARY  BONES. 

Articulations. — With  thirteen  bones :  two  of  the  cranium, — the  frontal 
and  sphenoid ;  the  rest  of  the  face,  viz.  the  nasal,  superior  maxillary,  la 
chrymal,  palate,  the  inferior  turbinated,  and  the  vomer. 

No  muscles  are  attached  to  this  bone. 

BONES   OF   THE   FACE. 

The  face  is  composed  of  fourteen  bones  ;  viz.  the 
Two  nasal,  Two  palate, 

Two  superior  maxillary.  Two  inferior  turbinated, 

Two  lachrymal,  Vomer, 

Two  malar,  Inferior  maxillary. 

NASAL  BONES. — The  nasal  (fig.  39)  are  two  small  quadrangular  bones, 
forming  by  their  union  the  bridge  and  base  of  the  nose.  Upon  the  upper 
surface  they  are  convex,  and  pierced  by  a  foramen  for  a  small  artery  ;  on 
the  under  surface  they  are  somewhat  concave,  and  marked  by  a  groove, 
which  lodges  the  nasal  branch  of  the  ophthalmic  nerve.  The  superior 
border  is  narrow  and  thick,  the  inferior  broad,  thin,  and  irregular. 

Development. — By  a  single  centre  for  each  bone,  the  first  ossific  depo- 
sition making  its  appearance  at  the  same  time  as  in  the  vertebra?. 

Articulations. — With  Jour  bones :  frontal,  ethmoidal,  nasal,  and  supe- 
rior maxillary. 

Attachment  of  Muscles. — It  has  in  relation  with  it  the  pyramidalis  nasi, 
and  compressor  nasi ;  but  neither  of  these  muscles  is  inserted  into  it. 

SUPERIOR  MAXILLARY  BONES. — The  superior  maxillary  are  the  largest 
bones  of  the  face,  with  the  exception  of  the  lower  jaw ;  they  form,  by  their 
union,  the  whole  of  the  upper  jaw,  and  assist  in  the  construction  of  the 
nose,  the  orbit,  the  cheek,  and  the  palate.  Each  bone  is  divisible  into  a 
body  and  four  processes. 

The  body  is  triangular  in  form,  and  hollowed  in 
its  interior  into  a  large  cavity,  the  antrum  maxillare 
(antrum  of  Highmore).  It  presents  for  examina- 
tion four  surfaces,  external  or  facial,  internal  or 
nasal,  posterior  or  zygomatic,  and  superior  or 
orbital. 

The  external,  or  facial  surface,  forms  the  anterior 
part  of  the  bone ;  it  is  irregularly  concave,  and 
presents  a  deep  depression  towards  its  centre,  the 
canine  fossa,  which  gives  attachment  to  two  mus- 
cles, the  compressor  nasi  and  levator  anguli  oris. 
Immediately  above  this  fossa  is  the  infra-orbital 
foramen,  the  termination  of  the  infra-orbital  canal, 
transmitting  the  superior  maxillary  nerve  and  infra- 
orbital  artery ;  and  above  the  infra-orbital  foramen, 

*  The  superior  maxillary  bone  of  the  right  side,  as  seen  from  the  lateral  aspect.  1. 
The  external  or  facial  surface;  the  depression  in  which  the  figure  is  placed  is  the  canine 
fossa.  2.  The  posterior,  or  zygomatic  surface.  3.  The  superior  or  orbital  surface.  4. 
The  infra-orbital  foramen  ;  it  is  situated  immediately  below  the  number.  5.  The  infra- 
orbital  canal,  leading  to  the  infra-orbital  foramen.  G.'The  inferior  border  of  the  orbit. 
7.  The  malar  process.  8.  The  nasal  process.  9.  The  concavity  forming  the  lateral 
boundary  of  the  anterior  nares.  10.  The  nasal  spine.  11.  The  incisive,  or  myrtifonn 
fossa.  12.  The  alveolar  process.  13.  The  internal  border  of  the  orbital  surface,  which 
maiculates  with  the  ethmoid  and  palate  bone.  14.  The  concavity  wl-.ich  articulates  with 


SUPERIOR  MAXILLARY  BOXES.  75 

the  lower  margin  of  the  orbit,  continuous  externally  with  the  rough  articu- 
lar surface  of  the  malar  process,  and  internally  with  a  thick  ascending  plate, 
the  nasal  process.  Towards  the  middle  line  of  the  face  this  surface  is 
bounded  by  the  concave  border  of  the  opening  of  the  nose,  which  is  pro- 
jected forwards  at  its  inferior  termination  into  a  sharp  process,  forming, 
with  a  similar  process  of  the  opposite  bone,  the  nasal  spine.  Beneath  the 
nasal  spine,  and  above  the  twro  superior  incisor  teeth,  is  a  slight  depression, 
the  incisive,  or  myrtiform  fossa,  which  gives  origin  to  the  depressor  labii 
superioris  alseque  nasi  muscle.  The  myrtiform  fossa  is  divided  from  the 
canine  fossa  by  a  perpendicular  ridge,  corresponding  with  the  direction 
of  the  root  of  the  canine  tooth.  The  inferior  boundary  of  the  facial  surface 
is  the  alveolar  process  which  contains  the  teeth  of  the  upper  jaw ;  and  it 
is  separated  from  the  zygomatic  surface  by  a  strong  projecting  eminence, 
the  malar  process. 

The  internal,  or  nasal  surface,  presents  a  large  irregular  opening,  lead- 
ing into  the  antrum  maxillare ;  this  opening  is  nearly  closed  in  the  articu- 
lated skull  by  the  ethmoid,  palate,  lachrymal,  and  inferior  turbinated  bones. 
The  cavity  of  the  antrum  is  somewhat  triangular,  corresponding  in  shape 
with  the  form  of  the  body  of  the  bone.  Upon  its  inner  wrall  are  numerous 
grooves,  lodging  branches  of  the  superior  maxillary  nerve,  and  projecting 
into  its  floor  several  conical  processes,  corresponding  with  the  roots  of  the 
first  and  second  molar  teeth.  In  front  of  the  opening  of  the  antrum  is  the 
strong  ascending  plate  of  the  nasal  process,  marked  inferiorly  by  a  rough 
horizontal  ridge  (crista  turbinalis  inferior),  which  gives  attachment  to  the 
inferior  turbinated  bone.  The  concave  depression  immediately  above  this 
ridge  corresponds  with  the  middle  meatus  of  the  nose,  and  that  below  the 
ridge  with  the  inferior  meatus.  Between  the  nasal  process  and  the  opening 
of  the  antrum,  is  a  deep  vertical  groove  (sulcus  lachrymalis)  which  is  con- 
verted into  a  canal  by  the  lachrymal  and  inferior  turbinated  bone,  and  consti- 
tutes the  nasal  duct.  The  superior  border  of  the  nasal  surface  is  irregularly 
cellular,  and  articulates  with  the  lachrymal  and  ethmoid  bone ;  the  poste- 
rior border  is  rough,  and  articulates  with  the  palate  bone ;  the  anterior 
border  is  sharp,  and  forms  the  free  margin  of  the  opening  of  the  nose  ;  and 
from  the  inferior  border  projects  inwards  a  strong  horizontal  plate,  the 
palate  process. 

The  posterior  surface  may  be  called  zygomatic,  from  forming  part  of 
the  zygomatic  fossa ;  it  is  bounded  externally  by  the  malar  process,  and 
internally  by  a  rough  and  rounded  border,  the  tuberosity,  which  is  pierced 
by  a  number  of  small  foramina  (foramina  alveolaria  posteriora),  giving 
passage  to  the  posterior  dental  nerves  and  branches  of  the  superior  dental 
artery.  The  lower  part  of  this  tuberosity  presents  a  rough  oval  surface,  to 
articulate  with  the  palate  bone,  and  immediately  above  and  to  the  inner 
side  of  this  articular  surface  a  smooth  groove,  which  forms  part  of  the  pos- 
terior palatine  canal.  The  superior  border  is  smooth  and  rounded  to  form 
the  lower  boundary  of  the  spheno-maxillary  fissure,  and  is  marked  by  a 
notch,  the  commencement  of  the  infra-orbital  canal.  The  inferior  boundary 
is  the  alveolar  process,  containing  the  last  two  molar  teeth. 

The  orbital  surface  is  triangular  and  thin,  and  constitutes  the  floor  of 
the  orbit.  It  is  bounded  internally  by  an  irregular  edge,  which  articulates 

the  lachrymal  bone,  and  forms  the  commencement  of  the  nasal  duct.  15.  The  crista 
nasalis  of  the  palate  process,  i.  The  two  incisor  teeth,  c.  The  canine,  b.  The  tw<? 
bicuspidati.  m.  The  three  molares. 


76  SUPERIOR  MAXILLARY  BONES. 

with  the  palate,  ethmoid,  and  lachrymal  bone  ;  posteriorly,  by  tne  smooth 
border  which  enters  into  the  formation  of  the  spheno-maxillary  fissure ; 
and,  anteriorly,  by  a  convex  margin,  partly  smooth  and  partly  rough,  the 
smooth  portion  forming  part  of  the  lower  border  of  the  orbit,  and  the 
rough  articulating  with  the  malar  bone.  The  middle  of  this  surface  is 
channelled  by  a  deep  groove  and  canal,  the  infra-orbital,  which  termi- 
nates at  the  infra-orbital  foramen ;  and  near  the  root  of  the  nasal  process 
is  a  slight  depression,  marking  the  origin  of  the  inferior  oblique  muscle  of 
the  eyeball. 

The  four  processes  of  the  superior  maxillary  bone  are  the  nasal,  malar, 
alveolar,  and  palate. 

The  nasal  process  ascends  by  the  side  of  the  nose,  to  which  it  forms  the 
lateral  boundary,  and  articulates  with  the  frontal  and  nasal  bone.  By  its 
external  surface  it  gives  attachment  to  the  levator  labii  superioris  alasque 
nasi,  and  to  the  orbicularis  palpebrarum  muscle.  Its  internal  surface  con- 
tributes to  form  the  inner  wall  of  the  nares,  and  is  marked  transversely  by 
a  horizontal  ridge  (crista  turbinalis  superior)  which  divides  it  into  two 
portions,  one  above  the  ridge,  irregular  and  uneven,  for  giving  attachment 
to  and  completing  the  cells  of  the  lateral  mass  of  the  ethmoid ;  the  other 
below,  smooth  and  concave,  corresponding  with  the  middle  meatus.  The 
posterior  border  is  thick,  and  hollowed  into  a  groove  for  the  nasal  duct. 
The  margin  of  the  nasal  process,  which  is  continuous  with  the  lower 
border  of  the  orbit,  is  sharp  and  marked  by  a  small  tubercle  which  serves 
as  a  guide  to  the  introduction  of  the  knife  in  the  operation  for  fistula 
lachrymalis. 

The  malar  process,  large  and  irregular,  is  situated  at  the  angle  of  sepa- 
ration between  the  facial  and  zygomatic  surfaces,  and  presents  a  triangular 
surface  for  articulation  with  the  malar  bone. 

The  alveolar  process  forms  the  lower  margin  of  the  bone  ;  it  is  spongy 
and  cellular  in  texture,  and  excavated  into  deep  holes  for  the  reception 
of  eight  teeth. 

The  palate  process  is  thick  and  strong,  and  projects  horizontally  inwyards 
from  the  inner  surface  of  the  body  of  the  bone.  Superiorly,  it  is  concave 
and  smooth,  and  forms  the  floor  of  the  nares ;  inferiorly,  it  is  also  concave 
but  uneven,  and  assists  in  the  formation  of  the  roof  of  the  palate.  This 
surface  is  marked  by  a  deep  groove,  which  lodges  the  posterior  palatine 
nerve  and  artery.  Its  internal  edge  is  raised  into  a  ridge  (crista  nasalis), 
which,  with  a  corresponding  ridge  in  the  opposite  bone,  forms  a  groove 
for  the  reception  of  the  vomer.  The  prolongation  of  this  ridge  forwards 
beyond  the  level  of  the  facial  surface  of  the  bone  is  the  nasal  spine.  At 
the  anterior  extremity  of  its  nasal  surface  is  a  foramen,  which  leads  into  a 
canal  formed  conjointly  by  the  two  superior  maxillary  bones,  the  anterior 
palatine  canal.  The  termination  of  this  canal  is  situated  immediately 
behind  the  incisor  teeth,  hence  it  is  also  named  the  incisive  foramen. 
Associated  with  the  incisive  openings  and  canal  are  two  smaller  canals, 
the  naso-palatine,  which  transmit  the  naso-palatine  nerves.  These  canals 
are  situated  in  the  walls  of  the  incisive  canal,  and  terminate  inferiorly  in 
that  canal,  either  by  separate  openings  or  conjoined. 

Development. — By  four  centres :  one  for  the  anterior  part  of  the  palate, 
and  incisive  portion  of  the  alveolar  process  (the  permanence  of  this  piece 
constitutes  the  intermaxillary  bone  of  animals) ;  one  for  that  portion  of  the 
oone  lying  internally  to  the  infra-orbital  canal  and  foramen ;  one  for  that 


LACHRYMAL    AND    MALAR    BOiNES.  77 

portion  lying  externally  to  the  infra-orbital  groove  and  canal ;  and  one 
for  the  palate  process.  The  superior  maxillary  bone  is  one  of  the  earliest 
to  show  signs  of  ossification,  this  process  beginning  in  the  alveolar  pro- 
cess, and  being  associated  with  the  early  development  of  teeth.  The 
early  development  of  the  alveolar  process,  and  the  consequent  fusion  at 
this  point  of  the  original  pieces,  explains  the  difficulties  which  have  been 
felt  by  anatomists  in  determining  the  precise  number  of  the  ossifying  cen- 
tres of  this  bone. 

Articulations.  —  With  nine  bones;  viz.  with  two  of  the  cranium,  and 
with  all  the  bones  of  the  face,  excepting  the  inferior  maxillary.  These 
are,  the  frontal  and  ethmoid ;  nasal,  lachrymal,  malar,  inferior  turbinated, 
palate,  vomer,  and  its  fellow  of  the  opposite  side. 

Attachment  of  Muscles. — To  nine;  orbicularis  palpebrarum,  obliquus 
inferior  oculi,  levator  labii  superioris  alseque  nasi,  levator  labii  superioris 
proprius,  levator  anguli  oris,  compressor  nasi,  depressor  labii  superioris 
alseque  nasi,  buccinator,  masseter. 

LACHRYMAL  BONES  (os  unguis,  from  an  imagined  resemblance  to  a 
finger-nail).  —  The  lachrymal  is  a  thin  oval-shaped  plate  of  bone,  situated 
at  the  anterior  and  inner  angle  of  the  orbit.  It  may  be  _,. 
divided  into  an  external  and  internal  surface  and  four  bor- 
ders. The  external  surface  is  smooth  and  marked  by  a  ver- 
tical ridge,  the  lachrymal  crest,  into  two  portions,  one  of 
which  is  flat  and  enters  into  the  formation  of  the  orbit,  hence 
may  be  called  the  orbital  portion  ;  the  other  is  concave,  and 
lodges  the  lachrymal  sac,  hence,  the  lachrymal  portion. 
The  crest  is  expanded  inferiorly  into  a  hook-shaped  process 
(hamulus  lachrymalis),  which  forms  part  of  the  outer  boundary 
of  the  fossa  lachrymalis.  The  internal  surface  is  uneven,  and  completes 
the  anterior  ethmoid  cells ;  it  assists  also  in  forming  the  wall  of  the  nasal 
fossae  and  nasal  duct.  The  four  borders  articulate  with  adjoining  bones. 

Development.  —  By  a  single  centre,  appearing  in  the  early  part  of  the 
third  month. 

Articulations.  —  With  four  bones :  two  of  the  cranium,  frontal  and 
ethmoid ;  and  two  of  the  face,  superior  maxillary  and  inferior  turbinated 
bone. 

Attachment  of  Muscles.  —  To  one  muscle,  the  tensor  tarsi,  and  to  an 
expansion  of  the  tendo  oculi,  the  former  arising  from  the  orbital  surface, 
the  other  being  attached  to  the  lachrymal  crest. 

MALAR  BONES  (mala,  the  cheek). — The  malar  (fig.  39)  is  the  strong  quad- 
rangular bone  which  forms  the  prominence  of  the  cheek.  It  is  divisible 
into  an  external  and  internal  surface  and  four  processes,  the  frontal,  orbital, 
maxillary,  and  zygomatic.  The  external  surface  is  smooth  and  convex, 
and  pierced  by  several  small  openings  which  give  passage  to  filaments  of 
the  temporo-malar  nerve  and  minute  arteries.  The  internal  surface  is 

*Tl:e  lachrymal  bone  of  the  right  side,  viewed  upon  its  external  or  orbital  surface. 
1.  The  orbital  portion  of  the  bone.  2.  The  lachrymal  portion  ;  the  prominent  ridge 
between  these  two  portions  is  the  crest.  3.  The  lower  termination  of  the  crest,  the 
harmi Ins  lachrymalis.  4.  The  superior  border  which  articulates  with  the  frontal  bone. 
5.  The  posterior  border,  which  articulates  with  the  ethmoid  bone.  6.  The  anteiior 
border,  which  articulates  with  the  superior  maxillary  bone.  7.  The  border  which  arn 
culates  with  the  inferioi  turbinated  bone. 
7* 


78  PALATE    BONES. 

concave,  partly  smooth  and  partly  rough;  smooth  where  it  forms  part  of 
the  temporal  fossa,  and  rough  where  it  articulates  with  the  superior  maxil- 
lary bone. 

The  frontal  process  ascends  perpendicularly  to  form  the  outer  border 
of  the  orbit,  and  to  articulate  with  the  external  angular  process  of  the 
frontal  bone.  The  orbital  process  is  a  thick  plate,  which  projects  inwards 
from  the  frontal  process,  and  unites  with  the  great  ala  of  the  sphenoid  to 
constitute  the  outer  wall  of  the  orbit.  It  is  pierced  by  several  small  fora- 
mina, for  the  passage  of  the  temporo-malar  filaments  of  the  superior 
maxillary  nerve.  The  maxillary  process  is  broad,  and  articulates  with 
the  superior  maxillary  bone.  The  zygomatic  process,  narrower  than  the 
rest,  projects  backwards  to  unite  with  the  zygoma  of  the  temporal  bone. 

Development. — By  a  single  centre ;  in  rare  instances,  by  two  or  three. 
In  many  animals  the  malar  bone  is  permanently  divided  into  two  portions, 
orbital  and  malar.  Ossification  commences  in  the  malar  bone  soon  after 
the  vertebrae. 

Articulations. — With  four  bones :  three  of  the  cranium,  frontal,  tem- 
poral, and  sphenoid  ;  and  one  of  the  face,  the  superior  maxillary  bone. 

Attachment  of  Muscles. — To  Jive:  levator  labii  superioris  proprius, 
zygomaticus  minor  and  major,  masseter,  and  temporal. 

PALATE  BONES. — The  palate  bones  are  situated  at  the  posterior  part  of 
the  nares,  where  they  enter  into  the  formation  of  the  palate,  the  side  of  the 
nose,  and  the  posterior  part  of  the  floor  of  the  orbit ; 
Fig.  36.  hence  they  might,  with  great  propriety,  be  named  the 

palato-naso-orbital  bones.  Each  bone  resembles,  ip 
general  form,  the  letter  L,  and  is  divisible  into  a 
horizontal  plate,  a  perpendicular  plate,  and  a  ptery- 
goid  process  or  tuberosity. 

The  horizontal  plate  is  quadrilateral;  and  presents 
two  surfaces,  one  superior,  which  enters  into  the  for- 
mation of  the  floor  of  the  nares,  the  other  inferior, 
forming  the  posterior  part  of  the  hard  palate.  The 
superior  surface  is  concave,  and  rises  towards  the 
middle  line,  where  it  unites  with  its  fellow  of  the 
opposite  side  and  forms  part  of  a  crest  (crista  nasalis),  which  articulates 
with  the  vomer.  The  inferior  surface  is  uneven,  and  marked  by  a  slight 
transverse  ridge,  to  which  is  attached  the  tendinous  expansion  of  the  ten- 
sor palati  muscle.  Near  its  external  border  are  two  openings,  one  large 
and  one  small,  the  posterior  palatine  foramina  ;  the  former  transmits  the 

*  A  posterior  view  of  the  right  palate  bone  in  its  natural  position;  it  is  slightly  turned 
on  one  side,  to  obtain  a  sight  of  the  internal  surface  of  the  perpendicular  plate  (2).  1.  The 
horizontal  plate  of  the  bone;  its  upper  or  nasal  surface.  2.  The  perpendicular  plate; 
its  internal  or  nasal  surface.  3,  10,  11.  The  pterygoid  process  or  tuberosity.  4.  The 
thick  internal  border  of  the  horizontal  plate,  which,  articulating  with  the  similar  border 
of  the  opposite  bone,  forms  the  crista  nasalis  for  the  reception  of  the  vomer.  5.  The 
pointed  process,  which,  with  a  similar  process  of  the  opposite  bone,  forms  the  palate 
spine. .  0.  The  horizontal  ridge  which  gives  attachment  to  the  inferior  turbinated  bone ; 
the  concavity  below  this  ridge  enters  into  the  formation  of  the  inferior  meatus,  and  the 
concavity  (2)  above  the  ridge  into  that  of  the  middle  meatus.  7.  The  spheno-palatine 
notch.  8.  The  orbital  portion.  9.  The  crista  turbinalis  superior  for  the  middle  turbi- 
uated  bone.  10.  The  middle  facet  of  the  tuberosity,  which  enters  into  the  formation  of 
the  pterygoid  fossa.  The  facets  11  and  3  articulate  with  the  two  pterygoid  plates,  11 
with  the  internal,  and  3  with  the  external. 


PALATE    BONES.  79 

posterior  palatine  nerve  and  artery,  and  the  latter  the  middle  palatine 
nerve.  The  posterior  border  is  concave,  and  presents  at  its  inner  extre- 
mity a  sharp  point,  which,  with  a  corresponding  point  in  the  opposite 
bone,  constitutes  the  palate  spine  for  the  attachment  of  the  azygos  uvulae 
muscle. 

The  perpendicular  plate  is  also  quadrilateral ;  and  presents  two  surfaces, 
one  internal  or  nasal,  forming  a  part  of  the  wall  of  the  nares ;  the  other 
external,  bounding  the  spheno-maxillary  fossa  and  antrum.  The  internal 
surface  is  marked  near  its  middle  by  a  horizontal  ridge  (crista  turbinalis 
inferior),  to  which  is  united  the  inferior  turbinated  bone ;  and,  at  about 
half  an  inch  above  this  is  another  ridge  (crista  turbinalis  superior)  for  the 
attachment  of  the  middle  turbinated  bone.  The  concave  surface  below 
(he  inferior  ridge  is  the  lateral  boundary  of  the  inferior  meatus  of  the  nose ; 
fliat  between  the  two  ridges  corresponds  with  the  middle  meatus,  and  the 
surface  above  the  superior  ridge  with  the  superior  meatus.  The  external 
surface,  extremely  irregular,  is  rough  on  each  side  for  articulation  with 
neighbouring  bones,  and  smooth  in  the  middle  to  constitute  the  inner 
boundary  of  the  spheno-maxillary  fossa.  This  smooth  surface  terminates 
inferiorly  in  a  deep  groove,  which  being  completed  by  the  tuberosity  of 
the  superior  maxillary  bone  and  pterygoid  process  of  the  sphenoid,  forms 
the  posterior  palatine  canal. 

Near  the  upper  part  of  the  perpendicular  plate  is  a  large  oval  notch 
completed  by  the  sphenoid,  the  spheno-palatine  foramen,  which  transmits 
the  spheno-palatine  nerves  and  artery,  and  serves  to  divide  the  upper  ex- 
tremity of  the  bone  into  two  portions,  an  anterior  or  orbital,  and  a  poste- 
rior or  sphenoidal  portion.  The  orbital  portion  is  hollow  within,  and  pre- 
sents five  surfaces  externally,  three  articular,  and  two  free  ;  the  three 
articular  are  the  anterior,  which  looks  forward  and  articulates  with  the 
superior  maxillary  bone,  the  internal  with  the  eth-  -pio.  37  * 

moid,'  and  the  posterior  writh  the  sphenoid.  The 
free  surfaces  are  the  superior  or  orbital,  which  forms 
the  posterior  part  of  the  floor  of  the  orbit,  and  the 
external,  which  looks  into  the  spheno-maxillary  fossa. 

The  sphenoidal  portion,  much  smaller  than  the 
orbital,  has  three  surfaces,  two  lateral  and  one  supe- 
rior. The  external  lateral  surface  enters  into  the 
formation  of  the  spheno-maxillary  fossa ;  the  internal 
lateral  forms  part  of  the  lateral  boundary  of  the  nares ; 
and  the  superior  surface  articulates  with  the  under 
part  of  the  body  of  the  sphenoid  bone,  and  assists 
the  sphenoidal  spongy  bones  in  closing  the  sphenoidal  sinuses.  This 
portion  takes  part  in  the  formation  of  the  pterygo-palatine  canal. 

The  pterygoid  process  or  tuberosity  of  the  palate  bone  is  the  thick  and 
rough  process  which  stands  backwards  from  the  angle  of  union  of  the 

*  The  perpendicular  plate  of  the  palate  bone  seen  upon  its  external  or  spheno-max- 
illary surface.  1.  The  rough  surface  of  this  plate,  which  articulates  with  the  superio* 
maxillary  bone  and  bounds  the  antrum.  2.  The  posterior  palatine  canal,  completed 
by  the  tuberosity  of  the  superior  maxillary  bone  and  pterygoid  process.  The  roug;; 
surface  to  the  left  of  the  canal  (2)  articulates  with  the  internal  pterygoid  plate.  .'!. 
The  spheno-palatine  notch.  4,  5,  6.  The  orbital  portion  of  the  perpendicular  plate.  4. 
The  spheno-maxillary  facet  of  this  portion;  5.  jts  orbital  facet;  6,  its  maxillary  facet, 
to  articulate  with  the  superior  maxillary  bone.  7.  The  sphenoidal  portion  of  \l?a  p*»- 
pendicular  plate.  8.  The  pterygoid  process  or  tuberosity  of  the  bone. 


80  INFERIOR    TURBINATED    BONES — VOMER. 

horizontal  with  the  perpendicular  portion  of  the  bone.  It  is  received  into 
the  angular  fissure,  which  exists  between  the  two  plates  of  the  pterygoid 
process  at  their  inferior  extremity,  and  presents  three  surfaces :  one  con- 
cave and  smooth,  which  forms  part  of  the  pterygoid  fossa ;  and  one  at 
each  side  to  articulate  with  the  pterygoid  plates.  The  anterior  face  of 
this  process  is  rough,  and  articulates  with  the  superior  maxillary  bone. 

Development. — By  a  single  centre,  which  appears  in  the  angle  of  union 
between  the  horizontal  and  perpendicular  portion,  at  the  same  time  with 
ossification  in  the  vertebra?. 

Articulations. — With  six  bones :  two  of  the  cranium,  the  sphenoid  and 
ethmoid  ;  and  four  of  the  face,  the  superior  maxillary,  inferior  turbinated 
bone,  vomer,  and  the  palate  bone  of  the  opposite  side. 

Attachment  of  muscles. — To  four :  the  tensor  palati,  azygos  uvulee, 
internal  and  external  pterygoid. 

INFERIOR  TURBINATED  BONES. — The  inferior  turbinated  or  spongy  bone, 
is  a  thin  layer  of  light  and  porous  bone,  attached  to  the  crista  turbinalis 
inferior  of  the  inner  wall  of  the  nares,  and  projecting  inwards  towards 
the  septum  narium.  The  inferior  turbinated  bone  is  broad  in  front,  nar- 
row and  tapering  behind,  and  slightly  curled  upon  itself,  so  as  to  bear 
some  resemblance  to  one  valve  of  a  bivalve  shell,  hence  its  designation 
concha  inferior.  The  bone  presents  for  examination  a  convex  and  a  con- 
cave surface,  and  a  superior  and  an  inferior  border.  The  convex  surface 
looks  inwards  and  upwards,  and  forms  the  inferior  boundary  of  the  middle 
meatus  naris ;  it  is  marked  by  several  longitudinal  grooves  for  branches 
of  the  spheno-palatine  nerve  and  artery.  The  concave  surface  looks  down- 
wards and  outwards,  and  constitutes  the  roof  of  the  inferior  meatus.  The 
superior  border  is  irregular ;  it  is  attached  to  the  crista  turbinalis  inferioi 
of  the  superior  maxillary  bone  in  front,  to  the  same  crest  on  the  palate 
bone  behind,  and  between  those  attachments  gives  off  two,  and  sometimes 
three,  thin  and  laminated  processes.  The  most  anterior  of  these  processes, 
processus  lachrymalis,  articulates  with  the  lachrymal  bone,  and  assists  in 
completing  the  nasal  duct.  The  middle  process,  processus  maxillaris, 
descends  and  assists  in  closing  the  antrum  maxillare ;  while  the  posterior, 
processus  ethmoidalis,  which  is  often  wanting,  ascends  towards  the  eth- 
moid bone,  and  also  takes  part  in  the  closure  of  the  antrum  maxillare. 
The  inferior  border  is  rounded,  and  thicker  than  the  rest  of  the  bone. 

Development. — By  a  single  centre,  which  appears  at  about  the  middle 
of  the  first  year. 

It  affords  no  attachment  to  muscles. 

Articulations. — With  four  bones :  the  ethmoid,  superior  maxillary,  la- 
chrymal, and  palate. 

VOMER. — The  vomer  is  a  thin,  quadrilateral,  plate  of  bone,  forming  the 
posterior  and  inferior  part  of  the  septum  of  the  nares. 

The  superior  border  is  broad  and  expanded,  to  articulate,  in  the  middle, 
with  the  under  surface  of  the  body  of  the  sphenoid,  and  on  each  side  with 
the  processus  vaginalis  of  the  pterygoid  process.  The  anterior  part  of  this 
border  is  hollowed  into  a  sheath  for  the  reception  of  the  rostrum  of  the 
sphenoid.  The  inferior  border  's  thin  and  irregular,  and  is  received  into 
the  grooved  summit  of  the  crista  nasalis.  The  posterior  border  is  sharp 
and  free,  and  forms  the  posterior  division  of  the  two  nares.  The  anterior 


INFERIOR    MAXILLARY    BONE.  81 

border  is  more  or  less  deeply  grooved  for  the  reception  of  the  central  la- 
mella of  the  ethmoid  and  the  cartilage  of  the  septum.  This  groove  is  an 
indication  of  the  early  constitution  of  the  bone  of  two  lamellae,  united  at 
the  inferior  border.  The  vomer  not  unfrequently  presents  a  convexity  to 
one  or  the  other  side,  generally,  it  is  said,  to  the  left. 

Development. — By  a  single  centre,  which  makes  its  appearance  at  the 
same  time  with  those  of  the  vertebra?.  Ossification  begins  from  below  and 
proceeds  upwards.  At  birth,  the  vomer  presents  the  form  of  a  trough,  in 
the  concavity  of  which  the  cartilage  of  the  septum  nasi  is  placed ;  it  is  this 
disposition  which  subsequently  enables  the  bone  to  embrace  the  rostrum  of 
the  sphenoid. 

'j\e  vomer  has  no  muscles  attached  to  it. 

jit  deviations. — With  six  bones:  the  sphenoid,  ethmoid,  two  superior 
maxillary,  and  two  palate  bones,  and  with  the  cartilage  of  the  septum. 

INFERIOR  MAXILLARY  BONE. — The  lower  jaw  is  the  arch  of  bone  which 
contains  the  inferior  teeth  ;  it  is  divisible  into  a  horizontal  portion  or  body, 
and  a  perpendicular  portion,  the  ramus,  at  each  side. 

Upon  the  external  surface  of  the  body  of  the  bone,  at  the  middle  line, 
and  extending  from  between  the  two  first  incisor  teeth  to  the  chin,  is  a 
slight  ridge,  crista  mentalis,  which  indicates  the  point  of  conjunction  of 
the  lateral  halves  of  the  bone  in  the  young  subject,  the  symphysis.  Im- 
mediately external  to  this  ridge  is  a  depression  which  gives  origin  to  the 
depressor  labii  inferioris  muscle  ;  and,  corresponding  with  the  root  of  the 
lateral  incisor  tooth,  another  depression,  the  incisive  fossa,  for  the  levator 
labii  inferioris.  Further  outwards  is  an  oblique  opening,  the  mental  fora- 
men, for  the  exit  of  the  inferior  dental  nerve  and  artery ;  and  below  this 
foramen  is  the  commencement  of  an  oblique  ridge  which  runs  upwards 
and  outwards  to  the  base  of  the  coronoid  process  and  gives  attachment  to 
the  depressor  anguli  oris,  platysma  myoides,  and  buccinator  muscle.  Near 
the  posterior  part  of  this  surface  is  a  rough  impression  made  by  the  mas- 
seter  muscle  ;  and  immediately  in  front  of  this  impression,  a  groove  may 
occasionally  be  seen  for  the  facial  artery.  The  projecting  tuberosity  at  the 
posterior  extremity  of  the  lower  jaw,  at  the  point  where  the  body  and  ramus 
meet,  is  the  angle. 

Upon  the  internal  surface  of  the  body  of  the  bone,  at  the  symphysis,  are 
two  small  pointed  tubercles ;  immediately  beneath  these,  two  other  tuber- 
cles, less  marked  and  pointed ;  beneath  them  a  ridge,  and  beneath  the 
ridge  two  rough  depressions  of  some  size.  These  four  points  give  attach- 
ment, from  above  downwards,  to  the  genio-hyo-glossi,  genio-hyoidei,  part 
of  the  mylo-hyoidei,  and  to  the  digastric  muscles.  Running  outwards 
into  the  body  of  the  bone  from  the  above  ridge  is  a  prominent  line,  the 
mylo-hyoidean  ridge,  which  gives  attachment  to  the  mylo-hyoideus  muscle, 
and  by  its  extremity  to  the  pterygo-maxillary  ligament  and  superior  con- 
strictor muscle.  Immediately  above  the  ridge,  and  by  the  side  of  the 
symphysis,  is  a  smooth  concave  surface,  which  corresponds  with  the  sub- 
lingual  gland ;  and  below  the  ridge,  and  more  externally,  a  deeper  fossa 
for  the  submaxillary  gland. 

The  superior  border  of  the  body  of  the  bone  is  the  alveolar  process, 
furnished  in  the  adult  with  alveoli  for  sixteen  teeth.  The  inferior  border 
or  base  is  rounded  and  smooth ;  thick  and  everted  in  front  to  form  the 
chin,  and  thin  behind  where  it  merges  into  the  angle  of  the  bone. 

F 


82  INFERIOR    MAXILLARY    BONE. 

The  ramus  is  a  strong  square-shaped  process,  differing  in  direction  at 
various  periods  of  life ;  thus,  in  the  foetus  and  infant,  it  is  almost  parallel 
with  the  body ;  in  youth  it  is  oblique,  and  it  gradually  approaches  the  ver- 
tical direction  until  manhood ;  in  old  age,  after  the  loss  of  the  teeth,  it 
again  declines  and  assumes  the  oblique  direction.  Upon  its  external  sur- 
face it  is  rough,  for  the  attachment  of  the  masseter  muscle ;  and  at  the 
junction  of  its  posterior  border  with  the  body  of  the  bone  is  a  rough  tuber- 
osity,  the  angle  of  the  lower  jaw,  which  gives  attachment  by  its  inner 
margin  to  the  stylo-maxillary  ligament. 

Fjo.  38*  The  upper  extremity  of  the  ramus  pre- 

sents two  processes,  separated  by  a  con- 
cave sweep,  the  sigmoid  notch.  The  an- 
terior is  the  coronoid  process ;  it  is  sharp 
and  pointed,  and  gives  attachment  by  its 
inner  surface  to  the  temporal  muscle. 
The  anterior  border  of  the  coronoid  pro- 
cess is  grooved  at  its  lower  part  for  the 
buccinator  muscle.  The  posterior  pro- 
cess is  the  condyle  of  the  lower  jaw,  which 
is  flattened  from  before  backwards,  oblique 
in  direction,  and  smooth  upon  its  upper 
surface,  to  articulate  with  the  glenoid  ca- 
vity of  the  temporal  bone.  The  constriction  around  the  base  of  the  con- 
dyle is  its  neck,  into  which  is  inserted  the  external  pterygoid  muscle.  The 
sigmoid  notch  is  crossed  by  the  masseteric  artery  and  nerve. 

The  internal  surface  of  the  ramus  is  marked  near  its  centre  by  a  large 
oblique  foramen,  the  inferior  dental,  for  the  entrance  of  the  inferior  dental 
artery  and  nerve  into  the  dental  canal.  Bounding  this  opening  is  a  sharp 
margin,  to  which  is  attached  the  internal  lateral  ligament,  and  passing 
downwards  from  the  opening  a  narrow  groove  which  lodges  the  mylo- 
hyoidean  nerve  with  a  small  artery  and  vein.  To  the  uneven  surface 
above,  and  in  front  of  the  inferior  dental  foramen,  is  attached  the  temporal 
muscle,  and  to  that  below  it  the  internal  pterygoid.  The  internal  surface 
of  the  neck  of  the  condyle  gives  attachment  to  the  external  pterygoid 
muscle ;  and  the  angle  to  the  stylo-maxillary  ligament. 

Development. — By  two  centres :  one  for  each  lateral  half,  the  two  sides 
meeting  at  the  symphysis,  where  they  become  united.  The  lower  jaw  is 
the  earliest  of  the  bones  of  the  skeleton  to  exhibit  ossification,  with  the 
exception  of  the  clavicle ;  ossific  union  of  the  symphysis  takes  place  during 
the  first  year. 

Articulations. — With  the  glenoid  fossse  of  the  two  temporal  bones, 
through  the  medium  of  a  fibro- cartilage. 

Attachment  of  Muscles. — To  fourteen  pairs :  by  the  external  surface, 
commencing  at  the  symphysis  and  proceeding  outwards, — levator  labii 
inferioris,  depressor  labii  inferioris,  depressor  anguli  oris,  platysma  myoides, 

*  The  lower  jaw.  1.  The  body.  2.  The  ramus.  3.  The  symphysis.  4.  The  fossa 
'or  the  depressor  Itbii  inferioris  muscle.  5.  The  mental  foramen.  6.  The  external 
oblique  ridge.  7.  The  groove  for  the  facial  artery ;  the  situation  of  the  groove  is  marked 
by  a  notch  in  the  bone  a  little  in  front  of  the  number.  8.  The  angle.  9.  The  extremity 
of  the  mylo-hyoidean  ridge.  10.  The  coronoid  process.  11.  The  condyle.  12.  The 
s-gmoid  notch  ]  3.  The  inferior  dental  foramen.  14.  The  mylo-hyoidean  groove.  15. 
T)ie  alveolar  process,  t.  The  middle  and  lateral  incisor  tooth  of  one  side.  t.  The  ca- 
rune  tooth,  b.  The  two  bicuspides.  m.  The  three  molares. 


TABLE    OF   DEVELOPMENTS,    ARTICULATIONS,    ETC.  83 

buccinator,  and  masseter;  by  the  internal  surface,  also  commencing  at  the 
symphysis,  the  genio-hyo-glossus,  genio-hyoideus,  mylo-hyoideus,  digas- 
tricus,  superior  constrictor,  temporal,  external  pterygoid,  and  internal 
pterygoid. 

fable  showing  the  Points  of  Development,  Articulations,  and  Attachment 
of  Muscles,  of  the  Bones  of  the  Head. 

Development.  Articulations.          Attachment  of  Muscles. 

Occipital      .     ,     .  7  ....  6  ....  13  pairs. 

Parietal  ....  1....  5....       1  muscle. 

Frontal   ....  2  ....  12  ....  2  pairs. 

Temporal     ...  5  ....  5  ....  14  muscles. 

Sphenoid     ...  12  ....  12  ....  12  pairs. 

Ethmoid      ...  3  ....  13  ....          none. 

Nasal      ....  1  ....  4  ....          none. 

Superior  maxillary  4  ....  9  ....  9  muscles. 

Lachrymal  ...  1  ....  4  ....  1       ib. 

Malar     ....  1  ....  4  ....  5       ib. 

Palate     ....  1  ....  6  ....  4      ib. 

Inferior  turbinated  1  ....  4  ....          none. 

Vomer    ....  1  ....  6  ....          none. 

Lower  jaw  ...  2  ....  2  ....  14  pairs. 

SUTUR2S. 

The  bones  of  the  cranium  and  face  are  connected  with  each  other  by 
means  of  sutures  (sutura,  a  seam),  of  which  there  are  four  principal  varie- 
ties— serrated,  squamous,  harmonia,  and  schindylesis. 

The  serrated  suture  is  formed  by  the  union  of  two  borders  possessing 
serrated  edges,  as  in  the  coronal,  sagittal,  and  lambdoid  sutures.  In  these 
sutures  the  serrations  are  formed  almost  wholly  by  the  external  table,  the 
edges  of  the  internal  table  lying  merely  in  apposition. 

The  squamous  suture  (squama,  a  scale)  is  formed  by  the  overlapping  of 
the  bevelled  edges  of  two  contiguous  bones,  as  in  the  articulation  between 
the  temporal  and  the  lower  border  of  the  parietal.  In  this  suture  the  ap- 
proximated surfaces  are  roughened,  so  as  to  adhere  mechanically  with 
each  other. 

The  harmonia  suture  (a'psn/,  to  adapt)  is  the  simple  apposition  of  conti- 
guous surfaces,  the  surfaces  being  more  or  less  rough  and  retentive.  This 
suture  is  seen  in  the  connection  between  the  superior  maxillary  bones,  or 
of  the  palate  processes  of  the  palate  bones  with  each  other. 

The  schindylesis  suture  (a^5u\f]fis,  a  fissure)  is  the  reception  of  one  bone 
into  a  sheath  or  fissure  of  another,  as  occurs  in  the  articulation  of  the  ros- 
trum of  the  sphenoid  with  the  vomer,  or  of  the  latter  with  the  perpendicular 
lamella  of  the  ethmoid,  and  with  the  crista  nasalis  of  the  superior  maxil- 
lary and  palate  bones. 

The  serrated  suture  is  formed  by  the  interlocking  of  the  radiating  fibres 
along  the  edges  of  the  flat  bones  of  the  cranium  during  growth.  When 
this  process  is  retarded  in  the  infant  by  over- distension  of  the  head,  as  in 
hydrocephalus,  and  sometimes  without  any  such  apparent  cause,  distinct 
ossific  centres  are  developed  in  the  interval  between  the  edges ;  and,  being 
surrounded  by  the  suture,  from  independent  pieces,  which  are  called  ossa 


84  SUPERIOR  REGION  OF  THE  SKULL. 

triquetra,  or  ossa  Wormiana.  In  the  lambdoid  suture  there  is  generally 
one  or  more  of  these  bones ;  and  in  a  beautiful  adult  hydrocephalic  skele- 
ton, in  the  possession  of  Mr.  Listen,  there  are  upwards  of  one  hundred. 

The  coronal  suture  (fig.  39)  extends  transversely  across  the  vertex  of  the 
skull,  from  the  upper  part  of  the  greater  wing  of  the  sphenoid  of  one  side 
to  the  same  point  on  the  opposite  side  ;  it  connects  the  frontal  with  the 
parietal  bones.  In  the  formation  of  this  suture  the  edges  of  the  articu 
lating  bones  are  bevelled,  so  that  the  parietal  rest  upon  the  frontal  at  each 
side,  and  in  the  middle  the  frontal  rests  upon  the  parietal  bones ;  they  thus 
afford  each  other  mutual  support  in  the  consolidation  of  the  skull. 

The  sagittal  suture  (fig.  39)  extends  longitudinally  backwards  along 
the  vertex  of  the  skull,  from  the  middle  of  the  coronal  to  the  apex  of  the 
lambdoid  suture.  It  is  very  much  serrated,  and  serves  to  unite  the  two 
parietal  bones.  In  the  young  subject,  and  sometimes  in  the  adult,  this 
suture  is  continued  through  the  middle  of  the  frontal  bone  to  the  root  of 
the  nose,  under  the  name  of  the  frontal  suture.  Ossa  triquetra  are  some- 
times found  in  the  sagittal  suture. 

The  lambdoid  suture  is  named  from  some  resemblance  to  the  Greek 
letter  A,  consisting  of  two  branches,  which  diverge  at  an  acute  angle  from 
the  extremity  of  the  sagittal  suture.  This  suture  connects  the  occipital 
with  the  parietal  bones.  At  the  posterior  and  inferior  angle  of  the  parietal 
bones,  the  lambdoid  suture  is  continued  onwards  in  a  curved  direction  into 
the  base  of  the  skull,  and  serves  to  unite  the  occipital  bone  with  the  mas- 
toid  portion  of  the  temporal,  under  the  name  of  additamentum  suturce 
lambdoidalis.  It  is  in  the  lambdoid  suture  that  ossa  triquetra  occur  most 
frequently. 

The  squamous  suture  (fig.  39)  unites  the  squamous  portion  of  the  tem- 
poral bone  with  the  greater  ala  of  the  sphenoid,  and  wdth  the  parietal, 
overlapping  the  lower  border  of  the  latter.  The  portion  of  the  suture 
which  is  continued  backwards  from  the  squamous  portion  of  the  bone  to 
the  lambdoid  suture,  and  connects  the  mastoid  portion  with  the  posterior 
inferior  angle  of  the  parietal,  is  the  additamentum  suturce  squamosce. 

The  additamentum  suturae  lambdoidalis,  and  additamentum  suturce 
•squamosge,  constitute  together  the  mastoid  suture. 

Across  the  upper  part  of  the  face  is  an  irregular  suture,  the  transverse, 
which  connects  the  frontal  bone  with  the  nasal,  superior  maxillary,  lachry- 
mal, ethmoid,  sphenoid,  and  malar  bones.  The  remaining  sutures  are 
too  unimportant  to  deserve  particular  names  or  description. 

REGIONS    OF    THE    SKULL. 

The  skull,  considered  as  a  whole,  is  divisible  into  four  regions :  a  supe- 
rior region,  or  vertex ;  a  lateral  region;  an  inferior  region,  or  base ;  and 
an  anterior  region,  the  face. 

The  SUPERIOR  REGION,  or  vertex  of  the  skull,  is  bounded  anteriorly  by 
the  frontal  eminences ;  on  each  side  by  the  temporal  ridges  and  parietal 
eminences  ;  and  behind  by  the  superior  curved  line  of  the  occipital  bone 
and  occipital  protuberance.  It  is  crossed  transversely  by  the  coronal 
suture,  and  marked  from  before  backwards  by  the  sagittal,  which  termi- 
nates posteriorly  in  the  lambdoid  suture.  Near  the  posterior  extremity 
i/  the  region,  and  on  each  side  of  the  sagittal  suture,  is  the  parietal 
foramen. 


LATERAL  REGION  OF  THE  SKULL. 


85 


Upon  the  inner  or  cerebral  surface  of  this  region  is  a  shallow  groove, 
extending  along  the  middle  line  from  before  backwards,  for  the  superior 


Fig.  39» 


longitudinal  sinus ;  on  either  side  of  this  groove  are  several  small  fossae 
for  the  Pacchionian  bodies,  and  further  outwards,  digital  fossae  correspond- 
ing with  the  convexities  of  the  convolutions,  and  numerous  ramified  mark- 
ings for  lodging  the  branches  of  the  arteria  meningea  media. 

The  LATERAL  REGION  of  the  skull  is  divisible  into  three  portions ;  tem- 
poral, naastoid,  and  zygomatic. 

The  temporal  portion,  or  temporal  fossa,  is  bounded  above  and  behind 
by  the  temporal  ridge,  in  front  by  the  external  angular  process  of  the 

*  A  front  view  of  the  skull.  1.  The  frontal  portion  of  the  frontal  bone.  The  2,  im- 
mediately over  the  root  of  the  nose,  refers  to  the  nasal  tuberosity;  the  3.  over  the  orbit, 
to  the  supra-orbital  ridge.  4.  The  optic  foramen.  5.  The  sphenoidal  fissure.  6.  The 
spheno-maxillary  fissure.  7.  The  lachrymal  fossa  in  the  lachrymal  bone,  the  com- 
mencement of  the  nasal  duct.  The  figures  4,  5,  6,  7,  are  within  the  orbit.  8.  The 
opening  of  the  anterior  nares,  divided  into  two  parts  by  the  vomer;  the  number  is 
placed  upon  the  latter.  9.  The  infra-orbital  foramen.  10.  The  malar  bone.  11.  The 
symphisis  of  the  lower  jaw.  12.  The  mental  foramen.  13.  The  ramus  of  the  lower 
jaw.  14.  The  parietal  bone.  15.  The  coronal  suture.  16.  The  temporal  bone.  17. 
The  squamous  suture.  18.  The  upper  part  of  the  great  ala  of  the  sphenoid  bone.  19. 
The  commencement  of  the  temporal  ridge.  20.  The  zygoma,  of  the  temporal  bone, 
assisting  to  form  the  zygomatic  arch.  21.  The  mastoid  process. 

j-The  cerebral  surface  of  the  base  of  the  skull.  1.  One  side  of  the  anterior  fossa;  the 
number  is  placed  on  the  roof  of  the  orbit,  formed  by  the  orbital  plate  of  the  frontal  bone. 
2.  The  lesser  wing  of  the  sphenoid.  3.  The  crista  galli.  4.  The  foramen  caecum. 
5.  The  cribriform  lamella  of  the  ethmoid.  6.  The  processus  olivaris.  7.  The  foramen, 
opticum.  8.  The  anterior  elinoid  process.  9.  The  carotid  groove  upon  the  side  of  the 
sella  turcica,  for  the  internal  carotid  artery  and  cavernous  sinus.  10,  11,  12.  The 
middle  fossa  of  the  base  of  the  skull.  10.  Marks  the  great  ala  of  the  sphenoid.  1.1. 
The  squamous  portion  of  the  temporal  bone.  12.  The  petrous  portion  of  the  temporal. 
13.  The  sella  turcica.  14.  The  basilar  portion  of  the  sphenoid  and  occipital  bone 
(clivus  Blumenbachii).  The  uneven  ridge  between  Nos.  13,  14,  is  the  dorsum  ephippii, 
and  the  prominent  angles  of  this  ridge  the  posterior  elinoid  processes.  15.  The  fora- 
men rotundum.  16.  The  foramen  ovale.  17.  The  foramen  spinosum  ;  the  small  irre- 
gular opening  between  17  and  12  is  the  hiatus  Fallopii.  18.  The  posterior  fossa  of  me 
base  of  the  skull.  19,  19.  The  groove  for  the  lateral  sinus.  20.  The  ridge  upon  the 
occipital  bone,  which  gives  attachment  to  the  falx  cerebelli.  21.  The  foramen  magnnm. 
82.  The  meatus  auditorius  internus.  23.  The  jugular  foramen. 

8 


86  BASE    OF    THE    SKULL. 

frontal  bone  and  by  the  malar  bone,  and  below  by  the  zygoma.  It  i$ 
formed  by  part  of  the  frontal,  great  wing  of  the  sphenoid,  parietal,  squa- 
mous  portion  of  the  temporal,  malar  bone,  and  zygoma,  and  lodges  the 
temporal  muscle  with  the  deep  temporal  arteries  and  nerves. 

The  mastoid  portion  is  rough,  for  the  attachment  of  muscles.  Upon  its 
posterior  part  is  the  mastoid  foramen,  and  below,  the  mastoid  process. 
In  front  of  the  mastoid  process  is  the  external  auditory  foramen,  surrounded 
by  the  external  auditory  process  ;  and  in  front  of  this  foramen  the  glenoid 
cavity,  bounded  above  by  the  middle  root  of  the  zygoma  and  in  front  by 
its  tubercle. 

The  zygomatic  portion  or  fossa  is  the  irregular  cavity  below  the  zygoma, 
bounded  in  front  by  the  superior  maxillary  bone,  internally  by  the  exter- 
nal pterygoid  plate,  above  by  part  of  the  great  wing  of  the  sphenoid  and 
squamous  portion  of  the  temporal  bone,  and  by  the  temporal  fossa,  and 
externally  by  the  zygomatic  arch  and  ramus  of  the  lower  jaw.  It  con- 
tains the  external  pterygoid,  with  part  of  the  temporal  and  internal  ptery- 
goid muscle,  and  the  internal  maxillary  artery  and  inferior  maxillary  nerve, 
with  their  branches.  On  the  inner  and  upper  side  of  the  zygomatic  fossa 
are  two  fissures,  the  spheno-maxillary  and  the  pterygo-maxillary.  The 
spheno-maxillary  fissure  is  horizontal  in  direction,  opens  into  the  orbit, 
and  is  situated  between  the  great  ala  of  the  sphenoid  and  the  superior 
maxillary  bone.  It  is  completed  externally  by  the  malar  bone.  The 
pterygo-maxillary  fissure  is  vertical,  and  descends  at  right  angles  from  the 
extremity  of  the  preceding.  It  is  situated  between  the  pterygoid  process 
and  the  tuberosity  of  the  superior  maxillary  bone,  and  transmits  the  inter- 
nal maxillary  artery.  At  the  angle  of  junction  of  these  two  fissures  is  a 
small  space,  the  spheno-maxillary  fossa,  bounded  by  the  sphenoid,  palate, 
and  superior  maxillary  bone.  In  this  space  are  seen  the  openingsvof  five 
foramina, — the  foramen  rotundum,  spheno-palatine,  ptery go-palatine,  pos- 
terior palatine,  and  Vidian.  The  spheno-maxillary  fossa  lodges  Meckel's 
ganglion  and  the  termination  of  the  internal  maxillary  artery. 

The  BASE  OF  THE  SKULL  presents  an  internal  or  cerebral,  and  an  exter- 
nal or  basilar  surface. 

The  cerebral  surface  is  divisible  into  three  parts,  which  are  named  the 
anterior,  middle,  and  posterior  fossa  of  the  base  of  the  cranium.  The 
anterior  fossa  is  somewhat  convex  on  each  side,  where  it  corresponds  with 
the  roofs  of  the  orbits ;  and  concave  in  the  middle,  in  the  situation  of  the 
ethmoid  bone  and  the  anterior  part  of  the  body  of  the  sphenoid.  The 
latter  and  the  lesser  wings  constitute  its  posterior  boundary.  It  supports 
the  anterior  lobes  of  the  cerebrum.  In  the  middle  line  of  this  fossa,  at  its 
anterior  part,  is  the  crista  galli ;  immediately  in  front  of  this  process,  the 
foramen  ccecum;  and  on  each  side  the  cribriform  plate,  with  its  foramina, 
for  the  transmission  of  the  filaments  of  the  olfactory  and  nasal  branch  of 
the  opthalrnic  nerve.  Farther  back  in  the  middle  line  is  the  processus 
olivaris,  and  on  the  sides  of  this  process  the  optic  foramina,  anterior  and 
middle  clinoid  processes,  and  vertical  grooves  for  the  internal  carotid 
arteries. 

The  middle  fossa  of  the  base,  deeper  than  the  preceding,  is  bounded  in 
front  by  the  lesser  wing  of  the  sphenoid  ;  behind,  by  the  petrous  portion 
of  the  temporal  bone ;  and  is  divided  into  two  lateral  parts  by  the  sella 
turcica.  It  is  formed  by  the  posterior  part  of  the  body,  great  ala,  and 
ppinous  process  of  the  sphenoid,  and  bv  the  petrous  and  squamous  portion 


BASE    OF    THE    SKULL.  87 

of  the  temporal  bones.  In  the  centre  of  this  fossa  is  the  sdla  turcica, 
which  lodges  the  pituitary  gland,  bounded  in  front  by  the  anterior  and 
middle,  and  behind  by  the  posterior  clinoid  processes.  On  each  side  of  the 
sella  turcica  is  the  carotid  groove  for  the  internal  carotid  artery,  the 
cavernous  plexus  of  nerves,  the  cavernous  sinus,  and  the  orbital  nerves ; 
and  a  little  farther  outwards  the  following  foramina,  from  before  back- 
wards : — sphenoidal  fissure  (foramen  lacerum  anterius),  for  the  transmission 
of  the  third,  fourth,  three  branches  of  the  ophthalmic  division  of  the  fifth, 
and  the  sixth  nerve,  and  ophthalmic  vein ;  foramen  rotundum,  for  the 
superior  maxillary  nerve ;  foramen  ovale,  for  the  inferior  maxillary  nerve, 
arteria  meningea  parva,  and  nervus  petrosus  superficialis  minor ;  foramen 
spinosvm,  for  the  arteria  meningea  media ;  foramen  lacerum  basis  cranii, 
which  gives  passage  to  the  internal  carotid  artery,  carotid  plexus,  and 
petrosal  branch  of  the  Vidian  nerve.  On  the  anterior  surface  of  the 
petrous  portion  of  the  temporal  bone  is  a  groove,  leading  to  a  fissured 
opening,  the  hiatus  Fallopii,  for  the  petrosal  branch  of  the  Vidian  nerve  ; 
and,  immediately  beneath  this,  a  smaller  foramen,  for  the  nervus  petrosus 
superficialis  minor.  Towards  the  apex  of  the  petrous  portion  is  the  notch 
for  the  fifth  nerve,  and  below  it  a  slight  depression  for  the  Casserian  gan- 
glion. Farther  outwards  is  the  eminence  which  marks  the  position  of  the 
perpendicular  semicircular  canal.  Proceeding  from  the  foramen  spinos-um, 
are  two  grooves  which  indicate  the  course  of  the  trunks  of  the  arteria 
meningea  media.  The  whole  fossa  lodges  the  middle  lobes  of  the 
cerebrum. 

The  posterior  fossa,  larger  than  the  other  two,  is  formed  by  the  occipital 
bone,  by  the  petrous  and  mastoid  portion  of  the  temporals,  and  by  a  srrall 
part  of  the  sphenoid  and  parietals.  It  is 
bounded  in  front  by  the  upper  border 
of  the  petrous  portion  and  dorsum  ephip- 
pii,  and  along  its  posterior  circumference 
by  the  groove  for  the  lateral  sinuses ;  it 
gives  support  to  the  pons  Varolii,  medulla 
oblongata,  and  cerebellum.  In  the  centre 
of  this  fossa  is  the  foramen  magnum, 
bounded  on  each  side  by  a  rough  tuber- 
cle, which  gives  attachment  to  the  odon- 
toid ligament,  and  by  the  anterior  condy- 
loid  foramen.  In  front  of  the  foramen 
magnum  is  the  concave  surface  (clivus 
Blumenbachii)  which  supports  the  me- 
dulla oblongata  and  pons  Varolii,  and  on 
each  side  the  following  foramina,  from 
oefore  backwards : — the  internal  auditory 
foramen,  for  the  auditory  and  facial  nerve 
and  auditory  artery  ;  behind,  and  exter- 
nally to  this,  is  a  small  foramen  leading 

*  The  external  or  basilar  surface  of  the  base  of  the  skull.  1,  1.  The  hard  palata 
The  figures  are  placed  upon  the  palate  processes  of  the  superior  maxillary  bones 
2.  The  incisive,  or  anterior  palatine  foramen.  3.  The  palate  process  of  the  palate  bono 
The  large  opening  near  the  figure  is  the  posterior  palatine  foramen.  4.  The  palate 
spine ;  the  curved  line  upon  which  the  number  rests  is  the  transverse  ridge.  5.  Th«» 
vomer,  dividing  the  openings  of  the  posterior  nares.  6.  The  internal  pterygoid  plate 


Fig.  41* 


88  BASE    OF    THE   .SKULL. 

into  the  aqucedudus  vestibuli;  and  below  it,  partly  concealed  by  the  edge 
of  the  petrous  bone,  the  aquceductus  cochlea;  next,  a  long  fissure,  the 
foramen  lacemm  posterius,  or  jugular  foramen,  giving  passage  externally 
to  the  commencement  of  the  internal  jugular  vein,  and  internally  to  the 
eighth  pair  of  nerves.  Converging  towards  this  foramen  from  behind  is 
the  deep  groove  for  the  lateral  sinus,  and  from  the  front  the  groove  for  the 
inferior  petrosal  sinus. 

Behind  the  foramen  magnum  is  a  longitudinal  ridge,  which  gives  at- 
tachment to  the  falx  cerebelli,  and  divides  the  two  inferior  fossae  of  the 
occipital  bone  ;  and  above  the  ridge  is  the  internal  occipital  protuberance 
and  the  transverse  groove  lodging  the  lateral  sinus. 

The  external  surface  of  the  base  of  the  skull  is  extremely  irregular. 
From  before  backwards  it  is  formed  by  the  pal  ate  processes  of  ihe  superior 
maxillary  and  palate  bones  ;  the  vomer ;  pterygoid,  spinous  processes,  and 
part  of  the  body  of  the  sphenoid  ;  under  surface  of  the  squamous,  petrous, 
and  mastoid  portion  of  the  temporals  ;  and  by  the  occipital  bone.  The 
palate  processes  of  the  superior  maxillary  and  palate  bones  constitute  the 
hard  palate,  which  is  raised  above  the  level  of  the  rest  of  the  base,  and  is 
surrounded  by  the  alveolar  processes  containing  the  teeth  of  the  upper 
jaw.  At  the  anterior  extremity  of  the  hard  palate,  and  directly  behind 
the  front  incisor  teeth,  is  the  anterior  palatine  or  incisive  foramen,  the  ter- 
mination of  the  anterior  palatine  canal,  which  contains  the  naso-palatine 
ganglion,  and  transmits  the  anterior  palatine  nerves.  At  the  posterior 
angles  of  the  palate  are  the  posterior  palatine  foramina,  for  the  posterior 
palatine  nerves  and  arteries.  Passing  inwards  from  these  foramina  are  the 
transverse  ridges  to  which  are  attached  the  aponeurotic  expansions  of  the 
tensor  palati  muscles ;  and  at  the  middle  line  of  the  posterior  border,  the 
palate  spine,  which  gives  origin  to  the  azygos  uvula.  The  hard  palate 
is  marked  by  a  crucial  suture,  which  distinguishes  the  four  processes  of 
which  it  is  composed.  Behind,  and  above  the  hard  palate,  are  the  poste- 
rior nares,  separated  by  the  vomer,  and  bounded  on  each  side  by  the  pte- 
rygoid processes.  At  the  base  of  the  pterygoid  processes  are  the  pterygo- 
palatine  canals.  The  internal  pterygoid  plate  is  long  and  narrow,  termi- 
nated at  its  apex  by  the  hamular  process,  and  at  its  base  by  the  scaphoid 
fossa.  The  external  plate  is  broad ;  the  space  between  the  two  is  the 
pterygoid  fossa  ;  it  contains  part  of  the  internal  pterygoid  muscle,  and  the 
tensor  palati.  Externally  to  the  external  pterygoid  plate  is  the  zygomatic 
fossa.  Behind  the  nasal  fossae,  in  the  middle  line,  is  the  under  surface  of 
the  body  of  the  sphenoid,  and  the  basilar  process  of  the  occipital  bone, 
and,  still  further  back,  the  foramen  magnum.  At  the  base  of  the  external 
pterygoid  plate,  on  each  side,  is  the  foramen  ovule,  and  behind  this  the 
foramen  spinosum  with  the  prominent  spine  which  gives  attachment  to  the 
internal  lateral  ligament  of  the  lower  jaw  and  the  laxator  tympani  muscle. 
Running  outwards  from  the  apex  of  the  spinous  process  of  the  sphenoid 

7.  The  scaphoid  fossa.  8.  The  external  pterygoid  plate.  The  interval  between  6  and 
S  fright  side  of  the  figure)  is  the  pterygoid  fossa.  9.  The  zygomatic  fossa.  10.  The 
basilar  process  of  the  occipital  bone.  11.  The  foramen  magnum.  12.  The  foramen 
ovale.  13.  The  foramen  spinosum.  14.  The  glenoid  fossa.  15.  The  meatus  audito- 
nus  externus.  16.  The  foramen  lacerum  anterius  basis  cranii.  17.  The  carotid  fora- 
men of  the  left  side.  18.  The  foramen  lacerum  posterius,  or  jugular  foramen.  19.  The 
styioid  process.  20.  The  stylo-mastoid  foramen.  21.  The  mastoid  process.  22.  Ona 
of  the  condyles  )f  the  occipital  bone.  23.  The  posterior  condyloid  fossa. 


REGION    OF    THE    FACE.  89 

bone,  is  the  fissura  Glaseri,  which  crosses  the  glenoid  fossa  transversely, 
and  divides  it  into  an  anterior  smooth  surface,  bounded  by  the  eminentia 
articularis,  for  the  condyle  of  the  lower  jaw,  and  a  posterior  rough  surface 
for  a  part  of  the  parotid  gland.  Behind  the  foramen  ovale  and  spinosum, 
is  the  irregular  fissure  between  the  spinous  process  of  the  sphenoid  bone 
and  the  petrous  portion  of  the  temporal,  the  fqramen  lacerum  anterius  basis 
cranii,  which  lodges  the  internal  carotid  artery  and  Eustachian  tube,  and  in 
which  the  carotid  branch  of  the  Vidian  nerve  joins  the  carotid  plexus. 
Following  the  direction  of  this  fissure  outwards  we  see  the  foramen  for  the 
Eustachian  tube,  and  that  for  the  tensor  tympani  muscle,  separated  from 
each  other  by  the  processus  cochleariformis.  Behind  the  fissure  is  the 
pointed  process  of  the  petrous  bone  which  gives  origin  to  the  levator  pa- 
lati  muscle,  and,  externally  to  this  process,  the  carotid  foramen  for  the 
transmission  of  the  internal  carotid  artery  and  the  ascending  branch  of  the 
superior  cervical  ganglion  of  the  sympathetic ;  and  behind  the  carotid 
foramen,  the  foramen  lacerum  posterius  and  jugular  fossa.  Externally, 
and  somewhat  in  front  of  the  latter,  is  the  styloid  process,  and  at  its  base 
the  vaginal  process.  Behind  and  at  the  root  of  the  styloid  process  is  the 
stylo-mastoid  foramen,  for  the  facial  nerve  and  stylo-mastoid  artery,  and 
further  outwards  the  mastoid  process.  Upon  the  inner  side  of  the  root 
of  the  mastoid  process  is  the  digastric  fossa ;  and  a  little  farther  inwards, 
the  occipital  groove.  On  either  side  of  the  foramen  magnum,  and  near 
its  anterior  circumference,  are  the  condyles  of  the  occipital  bonk.  In 
front  of  each  condyle,  and  piercing  its  base,  is  the  anterior  condyloid  fora- 
men for  the  hypoglossal  nerve,  and  directly  behind  the  condyle  the  irre- 
gular fossa  in  which  the  posterior  condyloid  foramen  is  situated.  Behind 
the  foramen  magnum  are  the  two  curved  lines  of  the  occipital  bone,  the 
spine,  and  the  protuberance,  with  rough  surfaces  for  the  attachment  of 
muscles. 

The  FACE  is  somewhat  oval  in  contour,  uneven  in  surface,  and  exca- 
•  vated  for  the  reception  of  two  principal  organs  of  sense, — the  eye  and  the 
nose.  It  is  formed  by  part  of  the  frontal  bone  and  by  the  bones  of  the 
face.  Superiorly  it  is  bounded  by  the  frontal  eminences  ;  beneath  these 
are  the  superciliary  ridges,  converging  towards  the  nasal  tuberosity;  be- 
neath the  superciliary  ridges  are  the  supra-orbital  ridges,  terminating  ex- 
ternally in  the  external  border  of  the  orbit,  and  internally  in  the  internal 
border,  and  presenting  towards  their  inner  third  the  supra-orbital  notch, 
for  the  supra-orbital  nerve  and  artery.  Beneath  the  supra-orbital  ridges 
are  the  openings  of  the  orbits.  Between  the  orbits  is  the  bridge  of  the 
nose,  over-arching  the  anterior  nares ;  and  on  each  side  of  this  opening 
the  canine  fossa  of  the  superior  maxillary  bone,  the  infra-orbital  foramen, 
and  still  farther  outwards  the  prominence  of  the  malar  bone ;  at  the  lower 
margin  of  the  anterior  nares  is  the  nasal  spine,  and  beneath  this  the  supe- 
rior alveolar  arch,  containing  the  teeth  of  the  upper  jaw.  Forming  the 
lower  boundary  of  the  face  is  the  lower  jaw,  containing  in  its  alveolar 
process  the  lower  teeth,  and  projecting  inferiorly  to  form  the  chin;  on 
either  side  of  the  chin  is  the  mental  foramen.  If  a  perpendicular  line  be 
drawn  from  the  inner  third  of  the  supra-orbital  ridge  to  the  inner  third  of 
the  body  of  the  lower  jaw,  it  will  be  found  to  intersect  three  openings  ;-•  • 
the  supra-orbital,  infra-orbital,  and  mental,  each  giving  passage  to  a  facial 
branch  of  the  fifth  nerve. 
8* 


90  ORBITS — NASAL   FOSSAE. 


ORBITS. 

The  orbits  are  two  quadrilateral  hollow  cones,  situated  in  the  uppei 
part  of  the  face,  and  intended  for  the  reception  of  the  eye-balls,  with  their 
muscles,  vessels,  and  nerves,  and  the  lachrymal  glands.  The  central  axis 
of  each  orbit  is  directed  outwards,  so  that  the  axis  of  the  two,  continued 
into  the  skull  through  the  optic  foramina,  would  intersect  over  the  middle 
of  the  sella  turcica.  The  superior  boundary  of  the  orbit  is  formed  by  the 
orbital  plate  of  the  frontal  bone,  and  by  part  of  the  lesser  wing  of  the 
sphenoid ;  the  inferior,  by  part  of  the  malar  bone  and  by  the  orbital  pro- 
cesses of  the  superior  maxillary  and  palate  bone ;  the  internal,  by  the 
lachrymal  bone,  the  os  planum  of  the  ethmoid,  and  part  of  the  body  of  the 
sphenoid ;  and  the  external,  by  the  orbital  process  of  the  malar  bone  and 
the  great  ala  of  the  sphenoid.  These  may  be  expressed  more  clearly  in  a 
tabular  form : — 

Frontal. 
Sphenoid  (lesser  wing). 


Inner  wall.  n   . 

Outer  wall. 


Lachrymal. 

Ethmoid  (os  planum). 

Sphenoid  (body). 


Orbit. 


Malar. 
Sphenoid  (greater  wing). 


Malar. 

Superior  Maxillary. 
Palate. 

There  are  nine  openings  communicating  writh  the  orbit :  the  optic,  for 
the  admission  of  the  optic  nerve  and  ophthalmic  artery ;  the  sphenoidal 
fissure,  for  the  transmission  of  the  third,  fourth,  the  three  branches  of  the 
ophthalmic  division  of  the  fifth  nerve,  the  sixth  nerve,  and  the  ophthalmic 
vein ;  the  spheno-maxillary  fissure,  for  the  passage  of  the  superior  maxil- 
lary nerve  and  artery  to  the  opening  of  entrance  of  the  infra-orbital  canal ; 
temporo-malar  foramina —  two  or  three  small  openings  in  the  orbital  pro- 
cess of  the  malar  bone,  for  the  passage  of  filaments  of  the  orbital  branch 
of  the  superior  maxillary  nerve ;  anterior  and  posterior  ethmoidal  foramina 
in  the  suture  between  the  os  planum  and  frontal  bone,  the  former  trans- 
mitting the  nasal  nerve  and  anterior  ethmoidal  artery,  the  latter  the  poste- 
rior ethmoidal  artery  and  vein ;  the  opening  of  the  nasal  duct ;  and  the 
supra-orbital  notch  or  foramen,  for  the  supra-orbital  nerve  and  artery. 

NASAL     FOSSAE. 

The  nasal  fossa?  are  two  irregular  cavities,  situated  in  the  middle  of  the 
face,  and  extending  from  before  backwards.  They  are  bounded  above  by 
the  nasal  bones,  ethmoid,  and  sphenoid  :  below  by  the  palate  processes  of 
the  superior  maxillary  and  palate  bones ;  externally  by  the  superior  maxil- 
lary, lachrymal,  inferior  turbinated,  superior  and  middle  turbinated  bones 
of  the  ethmoid,  palate,  and  internal  pterygoid  plate  of  the  sphenoid  ;  and 
the  two  fossae  are  separated  by  the  vomer  and  the  perpendicular  lamella 
of  the  ethmoid.  These  may  be  more  clearly  expressed  in  a  tabular 
form : — 


NASAL    FOSSAE 


91 


Nasal  bones. 

Ethmoid. 

Sphenoid. 

S 

2 

Qt 

^ 

. 

_rt 

13 

j 

cs 

"S 

"Si 

•a 

a 

13 

'3 

'3   •* 

.S  T3 

.  3 

Nasal  fossa. 

5 
ja 

Nasal  fossa. 

cs  S 

•S'o 

3    S 

(U    -fl 

S  b 

c! 

^    r^ 

*-*    — 

CC         4-1 

•a 

O    C- 
'ChJ 

O  £ 

—  e. 

OS 

0, 

«s 

s 

M 

3 

2 

C 

0) 

CG 

1—  1 

fl) 

S 

c 

o 

1—  « 

Fig.  42.* 


Palate  processes  of  superior  maxillary. 
Palate  processes  of  palate  bone. 

E^h  nasal  fossa  is  divided  into  three  irregular  longitudinal  passages, 
or  mcatuses,  by  three  processes  of  bone,  which  project  from  its  outer  wall, 
the  superior,  middle,  and  inferior  turbi- 
nated  bones;  the  superior  and  middle 
turbinated  bones  being  processes  of  the 
ethmoid,  and  the  inferior  a  distinct  bone 
of  the  face.  The  superior  meatus  occu- 
pies the  superior  and  posterior  part  of 
each  fossa ;  it  is  situated  between  the 
superior  and  middle  turbinated  bones, 
and  has  opening  into  it  three  foramina, 
viz.  the  opening  of  the  posterior  ethmoid 
cells,  the  opening  of  the  sphenoid  cells, 
and  the  spheno-palatine  foramen.  The 
middle  meatus  is  the  space  between  the 
middle  and  inferior  turbinated  bones ; 
it  also  presents  three  foramina,  the  open- 

*  A  longitudinal  section  of  the  nasal  fosssB  made  immediately  to  the  right  of  the 
middle  line,  and  the  bony  septum  removed  in  order  to  show  the  external  wall  of  the 
left  fossa.  1.  The  frontal  bone.  2.  The  nasal  bone.  3.  The  crista  galli  process  of  the 
ethmoid.  The  groove  between  1  and  3  is  the  lateral  boundary  of  the  foramen  caecum. 
4.  The  cribriform  plate  of  the  ethmoid.  5.  Part  of  the  sphenoidal  cells.  6.  The  basilar 
portion  of  the  sphenoid  bone.  Bones  2,  4,  and  5,  form  the  superior  boundary  of  the 
nasal  fossa.  7,  7.  The  articulating  surface  of  the  palatine  process  of  the  superior  maxil- 
lary bone.  The  groove  between  7,  7,  is  the  lateral  half  of  the  incisive  canal,  and  the 
dark  aperture  in  the  groove  the  inferior  termination  of  the  left  naso-palatine  canal 
8.  The  nasal  spine.  9.  The  palatine  process  of  the  palate  bone.  a.  The  superior  tur- 
binated bone,  marked  by  grooves  and  apertures  for  filaments  of  the  olfactory  nerve. 
6.  The  superior  meatus.  c.  A  probe  passed  into  the  posterior  ethmoidal  cells,  d.  The 
opening  of  the  sphenoidal  cells  into  the  superior  meatus.  e.  The  spheno-palatine  fora- 
men. /.  The  middle  turbinated  bone,  g,  g.  The  middle  meatus.  h.  A  probe  passed 
into  the  infundibular  canal,  leading  from  the  frontal  sinuses  and  anterior  ethmoid  cells; 
the  triangular  aperture  immediately  above  the  letter  is  the  opening  of  the  maxillary 
sinus,  i.  The  inferior  turbinated  bone,  k,  k.  The  inferior  meatus.  /,  /.  A  probe  passed 
up  the  nasal  duct,  showing  the  direction  of  that  canal.  The  anterior  letters  g,  k,  are 
placed  on  the  superior  maxillary  bone,  the  posterior  on  the  palate  bone.  m.  The  in- 
ternal pterygoid  plate,  n.  Its  hamular  process,  o.  The  external  pterygoid  plate,  p.  The 
situation  of  the  opening  of  the  Eustachian  tube.  q.  The  posterior  palatine  foramina. 
r.  The  roof  of  the  left  orbit.  *.  The  optic  foramen,  t.  The  groove  for  the  last  turn  of 
the  internal  carotid  artery  cor.verte.d  into  a  foramen  by  the  development  of  an  osseous 
communication  between  the  anterior  and  middle  clinoid  processes,  v.  The  sella  turcica. 
c.  The  posterior  clinoid  process. 


02  TEETH CLASSIFICATION. 

ing  of  the  frontal  sinuses,  of  the  anterior  ethmoid  cells,  and  of  the  antrum. 
The  largest  of  the  three  passages  is  the  inferior  meatus,  which  is  the  space 
between  the  inferior  turbinated  bone  and  the  floor  of  the  fossa ;  in  it  there 
are  two  foramina,  the  termination  of  the  nasal  duct,  and  one  opening  of 
the  anterior  palatine  canal.  The  nasal  fossae  commence  upon  the  face  by 
a  large  irregular  opening,  the  anterior  nares,  and  terminate  posteriorly  in 
the  two  posterior  nares. 

TEETH. 

Man  is  provided  with  two  successions  of  teeth ;  the  first  are  the  teeth 
of  childhood,  they  are  called  temporary,  deciduous,  or  milk  teeth ;  the 
second  continue  until  old  age,  and  are  named  permanent. 


The  permanent  teeth  are  thirty-two  in  number,  sixteen  in  each  jaw ;  they 
are  divisible  into  four  classes,  —  incisors,  of  which  there  are  four  in  each 
jaw,  two  central  and  two  lateral ;  canine,  two  above  and  two  below ; 
bicuspid,  four  above  and  four  below ;  and  molars,  six  above  and  six 
below. 

The  temporary  teeth  are  twenty  in  number  (fig.  44) ;  eight  incisors, 
four  canine,  and  eight  molars.  The  temporary  molars  have  four  tubercles, 
and  are  succeeded  by  the  permanent  bicuspides,  which  have  only  two 
tubercles. 

Each  tooth  is  divisible  into  a  crown,  which  is  the  part  apparent  above 
the  gum ;  a  constricted  portion  around  the  base  of  the  crown,  the  neck , 
and  a  root  or  fang,  which  is  contained  within  the  alveolus.  The  root  is 
invested  by  periosteum,  which  lines  the  alveolus,  and  is  then  reflected 
upon  the  root  of  the  tooth  as  far  as  its  neck. 

The  incisor  teeth  (cutting  teeth)  are  named  from  presenting  a  sharp  and 
cutting  edge,  formed  at  the  expense  of  the  posterior  surface.  The  crown 
is  flattened  from  before  backwards,  being  somewhat  convex  in  front  and 
concave  behind  ;  the  neck  is  considerably  constricted,  and  the  root  com- 
pressed from  side  to  side  ;  at  its  apex  is  a  small  opening  for  the  passage 
of  the  nerve  and  artery  of  the  tooth. 

*  Permanent  teeth,  a.  Central  incisor,  b.  Lateral  incisor,  c.  Cuspid  or  canine 
d.  First  bicuspid,  e.  Second  bicuspid.  /.  First  molar,  g.  Second  molar,  h  Third 
molar  or  dens  sapientia. 


STRUCTURE    OF    TEETH. 

Fig.  44.* 


The  canine  teeth  (cuspidati)  follow  the  incisors  in  order  from  before 
backwards ;  two  are  situated  in  the  upper  jaw,  one  on  each  side,  and  two 
in  the  lower.  The  crown  is  larger  than  that  of  the  incisors,  convex  be- 
fore and  concave  behind,  and  tapering  to  a  blunted  point.  The  root  is 
longer  than  that  of  all  the  other  teeth,  compressed  at  each  side,  and 
marked  by  a  slight  groove. 

The  bicuspid  teeth  (bicuspidati,  small  molars),  two  on  each  side  in  each 
jaw,  follow  the  canine,  and  are  intermediate  in  size  between  them  and 
the  molars.  The  crown  is  compressed  from  before  backwards,  and  sur- 
mounted by  two  tubercles,  one  internal,  the  other  external ;  the  neck  is 
oval :  the  root  compressed,  marked  on  each -side  by  a  deep  groove,  and 
bifid  near  its  apex.  The  teeth  of  the  upper  jaw  have  a  greater  tendency 
to  the  division  of  their  roots  than  those  of  the  lower,  and  the  posterior 
than  the  anterior  pair. 

The  molar  teeth  (multicuspidati,  grinders),  three  on  each  side  in  each 
jaw,  are  the  largest  of  the  permanent  set.  The  crown  is  quadrilateral, 
and  surmounted  by  four  tubercles,  the  neck  large  and  round,  and  the  root 
divided  into  several  fangs.  In  the  upper  jaw  the  first  and  second  molar 
teeth  have  three  roots,  sometimes  four,  which  are  more  or  less  widely 
separated  from  each  other,  two  of  the  roots  being  external,  the  other  in- 
ternal. In  the  lower  there  are  but  two  roots,  which  are  anterior  and  pos- 
terior ;  they  are  flattened  from  behind  forwards,  and  grooved  so  as  to 
mark  a  tendency  to  division.  The  third  molars,  or  dentes  sapientise,  are 
smaller  than  the  other  two  ;  they  present  three  tubercles  on  the  surface  of 
the  crown ;  and  me  root  is  single  and  grooved,  appearing  to  be  made  up 
of  four  or  five  fangs  compressed  together,  or  partially  divided.  In  the 
lower  jaw  the  fangs  are  frequently  separated  to  some  distance  from  each 
other,  and  much  curved,  so  as  to  offer  considerable  resistance  in  the  ope- 
ration of  extraction.! 

Structure. — The  base  of  the  crown  of  each  tooth  is  hollowed  in  its  in- 
terior into  a  small  cavity  which  is  continuous  with  a  canal  passing  through 
the  middle  of  each  fang.  The  cavity  and  canal,  or  canals,  constitute  the 
cavitas  pulpae,  and  contain  a  soft  cellulo-vascular  organ,  the  pulp,  which 
receives  its  supply  of  vessels  and  nerves  through  the  small  opening  at  the 
apex  of  each  root.  Mr.  Nasmyth,  to  whose  investigations  science  is  so 

*  Temporary  teeth,     a.  Central  incisor,    b.  Lateral  incisor,     c.  Canine,     d.  First  mo 
lar.     e.  Second  molar. 

fSee  an  excellent  practical  work,  "On  the  S'ructure,  Economy,  and  Pathology  of  the 
Teeth,"  by  Mr.  Lintott. 


94  STRUCTURE    OF    TEETH. 

much  indebted  for  our  present  knowledge  of  the  intimate  structure  and 
development  of  the  teeth,  has  observed  with  regard  to  the  pulp,  that  it  is 
composed  of  two  different  tissues,  vascular  and  reticular ;  the  former 
being  an  intricate  web  of  minute  vessels  terminating  in  simple  capillary 
loops,  the  latter  a  network  of  nucleated  cells  in  which  calcareous  salts  are 
gradually  deposited,  and  which  by  a  systematic  continuance  of  that  pro- 
cess are  gradually  converted  into  ivory.  This  process  naturally  takes 
place  at  the  surface  of  the  pulp,  and  as  the  pulp  is  thus  robbed  of  its  cells, 
new  cells  are  produced  by  the  capillary  plexus  to  supply  their  place,  and 
be  in  their  turn  similarly  transformed. 

A  tooth  is  composed  of  three  distinct  structures,  ivory  or  tooth-bone 
enamel,  and  a  cortical  substance  or  cementum. 
The  ivory  consists  of  very  minute,  tapering,  and 
branching  fibres  embedded  in  a  dense  homogene- 
ous, interfibrous  substance.  The  fibres  commence 
by  their  larger  ends  at  the  walls  of  the  cavitas 
pulpas  and  pursue  a  radiating  and  serpentine  course 
towards  the  periphery  of  the  tooth,  where  they  ter- 
minate in  ramifications  of  extreme  minuteness. 
These  fibres,  heretofore  considered  to  be  hollow 
tubuli,  have  been  shown  by  Mr.  Nasrnyth  to  be 
rows  of  minute  opaque  bodies,  arranged  in  a  linear 
series  (baccated  fibres,  Nasmyth),  to  be,  in  fact, 
the  nuclei  of  the  ivory  cells,  the  interfibrous  sub- 
stance being  the  rest  of  the  cell  filled  with  calca- 
reous matter.  In  the  natural  state  of  the  tooth  all 
trace  of  the  parietes  or  mode  of  connexion  of  the 
cells  is  lost,  but  after  steeping  in  weak  acid  the 
cellular  network  is  perfectly  distinct. 

The  enamel  forms  a  crust  over  the  whole  exposed  surface  of  the  crown 
of  the  tooth  to  the  commencement  of  its  root ;  it  is  thickest  over  the  upper 
part  of  the  crown,  and  becomes  gradually  thinner  as  it  approaches  the 
neck.  It  is  composed  of  minute  hexagonal  crystalline  fibres,  resting  by 
one  extremity  against  the  surface  of  the  ivory,  and  constituting  by  the 
other  the  free  surface  of  the  crown.  The  fibres  examined  on  the  face  of 
a  longitudinal  section  have  a  waving  arrangement,  and  consist,  like  those 
of  ivory,  of  cells  connected  by  their  surfaces  and  ends  and  filled  with  cal- 
careous substance.  When  the  latter  is  removed  by  weak  acid,  the  ena- 
mel presents  a  delicate  cellular  net- work  of  animal  matter. 

The  cortical  substance,  or  cementum,  (substantia  ostoidea,)  forms  a 
thin  coating  over  the  root  of  the  tooth,  from  the  termination  of  the  enamel 
to  the  opening  in  the  apex  of  the  fang.  In  structure  it  is  analogous  to 
bone,  and  is  characterized  by  the  presence  of  numerous  calcigerous  cells 
and  tubuli.  The  cementum  increases  in  thickness  with  the  advance  of 
age,  and  gives  rise  to  those  exostosed  appearances  occasionally  seen  in  the 
teeth  of  very  old  persons,  or  in  those  who  have  taken  much  mercury.  In 
old  age  the  cavitas  pulpse  is  often  found  filled  up  and  obliterated  by 

*  Microscopic  section  of  a  molar  tooth.  1.  Enamel  with  its  columns  and  larr.inated 
•tructure.  2.  Cortical  substance  or  cementum  on  the  outside  of  the  fang.  3.  Ivory, 
showing  tubuli.  4.  Foramen  entering  the  dental  cavity  from  the  end  of  the  fang.  This 
fang  has  a  bulbous  enlargement  in  consequence  of  a  hypertrophy  of  the  cementum. 
5  Dental  cavity.  6.  A  few  osseous  corpuscles  in  the  ivory  just  under  the  enamel. 


DEVELOPMENT    OF    TEETH.  95 

osseous  substance  analogous  to  the  cementum.  Mr.  Nasmyth  has  shown 
that  this,  like  the  other  structures  composing  a  tooth,  is  formed  of  cells 
having  a  reticular  arrangement. 

Development. — The  development  of  the  teeth  in  the  human  subject  has 
been  successfully  investigated  by  Mr.  Goodsir,  to  whose  interesting  re- 
searches I  am  indebted  for  the  following  narrative  : — * 

The  inquiries  of  Mr.  Goodsir  commenced  as  early  as  the  sixth  week 
after  conception,  in  an  embryo,  which  measured  seven  lines  and  a  half 
in  length  and  weighed  fifteen  grains.  At  this  early  period  each  upper 
jaw  presents  two  semicircular  folds  around  its  circumference ;  the  most 
external  is  the  true  lip ;  the  internal,  the  rudiment  of  the  palate  ;  and  be- 
tween these  is  a  deep  groove,  lined  by  the  common  mucous  membrane 
of  the  mouth.  A  little  later,  a  ridge  is  developed  from  the  floor  of  this 
groove  in  a  direction  from  behind  forwards,  this  is  the  rudiment  of  the 
external  alveolus  ;  and  the  arrangement  of  the  appearances  from  without 
inwards  at  this  period  is  the  following : — Most  externally  and  forming  the 
boundary  of  the  mouth,  is  the  lip ;  next  we  find  a  deep  groove,  which 
separates  the  lip  from  the  future  jaw ;  then  comes  the  external  alveolar 
ridge;  fourthly,  another  groove,  in  which  the  germs  of  the  teeth  are  de- 
veloped, the  primitive  dental  groove ;  fifthly,  a  rudiment  of  the  internal 
alveolar  ridge ;  and,  sixthly,  the  rudiment  of  the  future  palate  bounding 
the  whole  internally.  At  the  seventh  week  the  germ  of  the  first  decidu- 
ous molar  of  the  upper  jaw  has  made  its  appearance,  in  the  form  of  a 
"  simple,  free,  granular  papilla"  of  the  mucous  membrane,  projecting 
from  the  floor  of  the  primitive  dental  groove ;  at  the  eighth  week,  the  pa- 
pilla of  the  canine  tooth  is  developed ;  at  the  ninth  week,  the  papillae 
of  the  four  incisors  (the  middle  preceding  the  lateral)  appear ;  and 
at  the  tenth  week  the  papilla  of  the  second  molar  is  seen  behind  the  ante- 
rior molar  in  the  primitive  dental  groove.  So  that  at  this  early  period, 
viz.  the  tenth  week,  the  papillae  or  germs  of  the  whole  ten  deciduous  teeth 
of  the  upper  jaw  are  quite  distinct.  Those  of  the  lower  jaw  are  a  little 
more  tardy ;  the  papilla  of  the  first  molar  is  merely  a  slight  bulging  at  the 
seventh  week,  and  the  tenth  papilla  is  not  apparent  until  the  eleventh 
week. 

From  about  the  eighth  week  the  primitive  dental  groove  becomes  con- 
tracted before  and  behind  the  first  deciduous  molar,  and  laminae  of  the 
mucous  membrane  are  developed  around  the  other  papillae,  which  increase 
in  growth  and  enclose  the  papillas  in  follicles  with  open  mouths.  At  the 
tenth  week  the  follicle  of  the  first  molar  is  completed,  then  that  of  the 
canine ;  during  the  eleventh  and  twelfth  weeks  the  follicles  of  the  incisors 
succeed,  and  at  the  thirteenth  week  the  follicle  of  the  posterior  deciduous 
molar. 

During  the  thirteenth  week  the  papillae  undergo  an  alteration  of  form, 
and  assume  the  shape  of  the  teeth  they  are  intended  to  represent.  And 
at  the  same  time  small  membranous  processes  are  developed  from  &e 
mouths  of  the  follicles ;  these  processes  are  intended  to  serve  the  purpose 
of  opercula  to  the  follicles,  and  they  correspond  in  shape  with  the  form 
of  the  crowns  of  the  appertaining  teeth.  To  the  follicles  of  the  incisoi 
teeth  there  are  two  opercula  ;  to  the  canine,  three ;  and  to  the  molars  a 
number  relative  to  the  number  of  their  tubercles,  either  four  or  five.  Dur 

*  "On  the  Origin  and  Development  of  the  Pulps  and  Sacs  of  the  Human  Teeth,"  bj 
John  Goodsir,  jun.,  in  the  Edinburgh  Medical  and  Surgical  Journal,  January,  ±839 


96  DEVELOPMENT    OF    TEETH. 

ing  the  fourteenth  and  fifteenth  weeks  the  opercula  have  completely  closed 
the  follicles,  so  as  to  convert  them  into  dental  sacs,  and  at  the  same  time 
the  papilla?  have  become  pulps. 

The  deep  portion  of  the  primitive  dental  groove,  viz.  that  which  contains 
the  dental  sacs  of  the  deciduous  teeth,  being  thus  closed  in,  the  remaining 
portion,  that  which  is  nearer  the  surface  of  the  gum,  is  still  left  open,  and 
to  this  Mr.  Goodsir  has  given  the  title  of  secondary  dental  groove;  as  it 
serves  for  the  development  of  all  the  permanent  teeth,  with  the  exception 
of  the  anterior  molars.  During  the  fourteenth  and  fifteenth  weeks  small 
lunated  inflections  of  the  mucous  membrane  are  formed,  immediately  to 
the  inner  side  of  the  closing  opercula  of  the  deciduous  dental  follicles, 
commencing  behind  the  incisors  and  proceeding  onwards  through  the  rest; 
these  are  the  rudiments  of  the  follicles  or  cavities  of  reserve  of  the  four 
permanent  incisors,  two  permanent  canines,  and  the  four  bicuspides.  As 
the  secondary  dental  groove  gradually  closes,  these  follicular  inflections 
of  the  mucous  membrane  are  converted  into  closed  cavities  of  reserve, 
which  recede  from  the  surface  of  the  gum  and  lie  immediately  to  the 
inner  side  and  in  close  contact  with  the  dental  sacs  of  the  deciduous  teeth, 
being  enclosed  in  their  submucous  cellular  tissue.  At  about  the  fifth 
month  the  anterior  of  these  cavities  of  reserve  dilate  at  their  distal  extre- 
mities, and  a  fold  or  papilla  projects  into  their  fundus,  constituting  the 
rudiment  of  the  germ  of  the  permanent  tooth  ;  at  the  same  time  two  small 
opercular  folds  are  produced  at  their  proximal  or  small  extremities,  and 
convert  them  into  true  dental  sacs. 

During  the  fifth  month  the  posterior  part  of  the  primitive  dental  groove 
behind  the  sac  of  the  last  deciduous  tooth  has  remained  open,  and  in  it 
has  developed  the  papilla  and  follicle  of  the  first  permanent  molar.  Upon 
the  closure  of  this  follicle  by  its  opercula,  the  secondary  dental  groove 
upon  the  summit  of  its  crown  forms  a  large  cavity  of  reserve,  lying  in 
contact  with  the  dental  sac  upon  the  one  side  and  with  the  gum  on  the 
superficial  side.  At  this  period  the  deciduous  teeth,  and  the  sacs  of  the 
ten  anterior  permanent  teeth,  increase  so  much  in  size,  without  a  corre- 
sponding lengthening  of  the  jaws,  that  the  first  permanent  molars  are  gra- 
dually pressed  backwards  and  upwards  into  the  maxillary  tuberosity  in 
the  upper  jaw,  and  into  the  base  of  the  coronoid  process  of  the  lower  jaw ; 
a  position  which  they  occupy  at  the  eighth  and  ninth  months  of  foetal  life. 
In  tht  infant  of  seven  or  eight  months  the  jaws  have  grown  in  length,  and 
the  first  permanent  molar  returns  to  its  proper  position  in  the  dental  range. 
Thf  cavity  of  reserve,  which  has  been  previously  elongated  by  the  upward 
movement  of  the  first  permanent  molar,  now  dilates  into  the  cavity  which 
that  tooth  has  just  quitted ;  a  papilla  is  developed  from  its  furidus,  the 
cavity  becomes  constricted,  and  the  dental  sac  of  the  second  molar  tooth 
is  formed,  still  leaving  a  portion  of  the  great  cavity  of  reserve  in  connexion 
with  the  superficial  side  of  the  sac.  As  the  jaws  continue  to  grow  in 
length,  the  second  permanent  dental  sac  descends  from  its  elevated  posi- 
tion and  advances  forwards  into  the  dental  range,  following  the  same 
curve  with  the  first  permanent  molar.  The  remainder  of  the  cavity  of 
reserve,  already  lengthened  backwards  by  the  previous  position  of  the 
second  molar,  again  dilates  for  the  last  time,  developes  a  papilla  and  sac 
in  the  same  manner  with  the  preceding,  and  forms  the  third  permanent 
*nolar  or  wisdom  tooth,  which  at  the  age  of  nineteen  or  twenty,  upon  the 


GROWTH    OF    TEETH.  97 

increased  growth  of  the  jaw,  follows  the  course  of  the  first  and  second 
molars  into  the  dental  range. 

From  a  consideration  of  the  foregoing  phenomena,  Mr.  Goodsir  has 
divided  the  process  of  dentition  into  three  natural  stages: — 1.  follicular; 
2.  saccular ;  3.  eruptive.  The  first,  or  follicular  stage,  he  makes  to 
include  all  the  changes  which  take  place  from  the  first  appearance  of  the 
dental  groove  and  papillae  to  the  closure  of  their  follicles ;  occupying  a 
period  which  extends  from  the  sixth  week  to  the  fourth  or  fifth  month  of 
intra-uterine  existence.  The  second,  or  saccular  stage,  comprises  the 
period  when  the  follicles  are  shut  sacs,  and  the  included  papillae  pulps : 
it  commences  at  the  fourth  and  fifth  months  of  intra-uterine  existence,  and 
terminates  for  the  median  incisors,  at  the  seventh  or  eighth  month  of 
infantile  life,  and  for  the  wisdom  teeth  at  about  the  twenty-first  year. 
The  third,  or  eruptive  stage,  includes  the  completion  of  the  teeth,  the 
eruption  and  shedding  of  the  temporary  set,  the  eruption  of  the  perma- 
nent, and  the  necessary  changes  in  the  alveolar  processes.  It  extends 
from  the  seventh  month  till  the  twenty-first  year. 

"  The  anterior  permanent  molar"  says  Mr.  Goodsir,  "  is  the  most 
remarkable  tooth  in  man,  as  it  forms  a  transition  between  the  milk  and  the 
permanent  set."  If  considered  anatomically,  i.  e.  in  its  development 
from  the  primitive  dental  groove,  by  a  papilla  and  follicle,  "  it  is  decidedly 
a  milk  tooth ;"  if  physiologically,  "  as  the  most  efficient  grinder  in  the 
adult  mouth,  we  must  consider  it  a  permanent  tooth."  "  It  is  a  curious 
circumstance,  and  one  which  will  readily  suggest  itself  to  the  surgeon, 
that  laying  out  of  view  the  wisdom  teeth,  which  sometimes  decay  at  an 
early  period  from  other  causes,  the  anterior  molars  are  the  permanent  teeth 
which  most  frequently  give  way  first,  and  in  the  most  symmetrical  manner 
and  at  the  same  time,  and  frequently  before  the  milk  set." 

Growth  of  Teeth. — Immediately  that  the  dental  follicles  have  been 
closed  by  their  opercula,  the  pulps  become  moulded  into  the  form  of  the 
future  teeth :  and  the  bases  of  the  molars  divided  into  two  or  three  por- 
tions representing  the  future  fangs.  The  dental  sac  is  composed  of  two 
layers,  an  internal  or  vascular  layer,  which  was  originally  a  part  of  the 
mucous  surface  of  the  mouth,  and  a  cellulo-fibrous  layer,  analogous  to  the 
corium  of  the  mucous  membrane.  Upon  the  formation  of  this  sac  by  the 
closure  of  the  follicle,  the  mucous  membrane  resembles  a  serous  mem- 
brane in  being  a  shut  sac,  and  may  be  considered  as  consisting  of  a  tunica 
propria,  which  invests  the  pulp  ;  and  a  tunica  reflexa,  which  is  adherent 
by  its  outer  surface  with  the  structures  in  the  jaw,  and  by  the  inner  surface 
is  free,  being  separated  from  the  pulp  by  an  intervening  cavity.  As  soon 
as  the  moulding  of  the  pulp  has  commenced,  this  cavity  increases  and 
becomes  filled  with  a  gelatinous  granular 
substance,  the  enamel  organ,  which  is  ad- 
herent to  the  whole  internal  surface  of  the 
tunica  reflexa,  but  not  to  the  tunica  propria 
and  pulp.  At  the  same  period,  viz.,  dur- 
ing the  fourth  or  fifth  month,  a  thin  lamina 
of  ivory  is  formed  by  the  pulp,  and  occu- 
pies its  most  prominent  point ;  if  the  tooth 

*  a.  Capsule  of  a  temporary  incisor  with  the  rudiment  of  the  corresponding  perma- 
nent tooth  attached,  b.  Capsule  of  a  molar  in  the  same  state.  A  part  of  the  gum  i» 
seen  above  it  and  in  contact. 

9  G 


08  TEETH — ERUPTION. 

be  incisor  or  canine,  the  newly-formed  layer  has  the  figure  of  a  small 
hollow  cone  ;  if  molar,  there  will  be  four  or  five  small  cones  correspond- 
ing with  the  number  of  tubercles  in  its  crown.  These  cones  are  united 
by  the  formation  of  additional  layers,  the  pulp  becomes  gradually  sur- 
rounded and  diminishes  in  size,  evolving  fresh  layers  during  its  retreat 
into  the  jaws  until  the  entire  tooth  with  its  fangs  is  completed,  and  the 
small  cavitas  pulpas  of  the  perfect  tooth  alone  remains,  communicating 
through  the  opening  in  the  apex  of  each  fang  with  the  dental  vessels  and 
nerves.  The  number  of  roots  appears  to  depend  upon  the  number  of 
nervous  filaments  sent  to  each  pulp.  When  the  formation  of  the  ivory 
has  commenced,  the  enamel  organ  becomes  transformed  into  a  laminated 
tissue,  corresponding  with  the  direction  of  the  fibres  of  the  enamel,  and 
the  crystalline  substance  of  the  enamel  is  secreted  into  its  meshes  by  the 
vascular  lining  of  the  sac. 

The  cementum  appears  to  be  formed  at  a  later  period  of  life,  either  by  a 
deposition  of  osseous  substance  by  that  portion  of  the  dental  sac,  which 
continues  to  enclose  the  fang,  and  acts  as  its  periosteum,  or  by  the  con- 
version of  that  membrane  itself  into  bone ;  the  former  supposition  is  the 
more  probable. 

The  formation  of  ivory  commences  in  the  first  permanent  molar  pre- 
viously to  birth. 

Eruption. — When  the  crown  of  the  tooth  has  been  formed  and  coated 
with  enamel,  and  the  fang  has  grown  to  the  bottom  of  its  socket  by  the 
progressive  lengthening  of  the  pulp,  the  formation  of  ivory,  and  the  ad- 
hesion of  the  ivory  to  the  contiguous  portion  of  the  sac,  the  pressure  of  the 
socket  causes  the  reflected  portion  of  the  sac  and  the  edge  of  the  tooth  to 
approach,  and  the  latter  to  pass  through  the  gum.  The  sac  has  thereby 
resumed*  its  original  follicular  condition,  and  has  become  continuous  with 
the  mucous  membrane  of  the  mouth.  The  opened  sac  now  begins  to 
shorten  more  rapidly  than  the  fang  lengthens,  and  the  tooth  is  quickly 
drawn  upwards  by  the  contraction,  leaving  a  space  between  the  extremity 
of  the  unfinished  root  and  the  bottom  of  the  socket,  in  which  the  growth 
and  completion  of  the  fang  is  more  speedily  effected. 

During  the  changes  which  have  here  been  described  as  taking  place 
among  the  dental  sacs  contained  within  the  jaws,  the  septa  between  the 
sacs,  which  at  first  were  composed  of  spongy  tissue,  soon  became  fibrous, 
and  were  afterwards  formed  of  bone,  which  was  developed  from  the  sur- 
face and  proceeded  by  degrees  more  deeply  into  the  jaws,  to  constitute 
the  alveoli.  The  sacs  of  the  ten  anterior  permanent  teeth,  at  first  enclosed 
in  the  submucous  cellular  tissue  of  the  deciduous  dental  sacs,  and  received 
Fig.  47,-j-  during  their  growth  into  crypts  situated  behind  the  deciduous 
teeth,  advanced  by  degrees  beneath  the  fangs  of  those  teeth, 
and  became  separated  from  them  by  distinct  osseous  alveoli. 
The  necks  of  the  sacs  of  the  permanent  teeth,  by  which  they 
originally  communicated  with  the  mucous  lining  of  the  second- 
ary groove,  still  exist,  in  the  form  of  minute  obliterated  cords, 
separated  from  the  deciduous  teeth  by  their  alveolus,  but  com- 
municating through  a  minute  osseous  canal  with  the  fibrous 
tissue  of  the  palate,  immediately  behind  the  corresponding  de- 

*  Mr.  Nasmyth  is  of  opinion  that  it  is  "  by  a  process  of  absorption,  and  not  of  disrup- 
tion, that  the  tooth  is  emancipated.''  Medico-chirurgical  Transactions.  1839. 

|  Temporary  tooth  with  the  capsule  of  its  permanent  successor  attached  to  it  by  the 
yubernaculum  demis. 


OS    HYOIDES.  99 

ciduous  teeth.  "These  cords  and  foramina  are  not  obliterated  in  the 
child,"  says  Mr.  Goodsir,  "either  because  the  cords  are  to  become 
useful  as  '  gubernacula?  and  the  canals  as  litinera  dentium;'  or,  mudi 
more  probably,  in  virtue  of  a  law,  which  appears  to  be  a  general  one  in  the 
development  of  animal  bodies,  viz.  that  parts,  or  organs,  which  have  once 
acted  an  important  part,  however  atrophied  they  may  afterwards  become,  yet 
never  altogether  disappear,  so  long  as  they  do  not  interfere  with  other  parts 
or  functions" 

Succession. — The  periods  of  appearance  of  the  teeth  are  extremely  irre- 
gular ;  it  is  necessary,  therefore,  to  have  recourse  to  an  average,  which, 
for  the  temporary  teeth,  may  be  stated  as  follows,  the  teeth  of  the  lower 
jaw  preceding  those  of  the  upper  by  a  short  interval : — 
7th  month,  two  middle  incisors.          18th  month,  canine. 
9th  month,  two  lateral  incisors.  24th  month,  two  last  molares. 

12th  month,  first  molares. 

The  periods  for  the  permanent  teeth  are, 

6.J   year,  first  molares.  10th  year,  second  bicuspides. 

7th  year,  two  middle  incisors.       llth  to  12th  year,  canine. 

8th  year,  two  lateral  incisors.         12th  to  13th  year,  second  molares. 

9th  year,  first  bicuspides.  17th  to  21st  year,  last  molares. 

OS    HYOIDES. 

The  05  hyoides  forms  the  second  arch  developed  from  the  cranium,  and 
gives  support  to  the  tongue,  and  attachment  to  numerous  muscles  in  the 
neck.  It  is  named  from  its  resemblance  to  the  Greek  letter  u,  and  consists 
of  a  central  portion  or  body,  of  two  larger  cornua,  which  project  backwards 
from  the  body ;  and  two  lesser  cornua,  which  ascend  from  the  angles  of 
union  between  the  body  and  the  greater  cornua. 

The  body  is  somewhat  quadrilateral,  rough 
and  convex  on  its  antero-superior  surface,  by 
which  it  gives  attachment  to  muscles ;  concave 
and  smooth  on  the  postero-inferior  surface,  by 
which  it  lies  in  contact  with  the  thyro-hyoidean 
membrane.  The  greater  cornua  are  flattened 
from  above  downwards,  and  terminated  posteri- 
orly by  a  tubercle ;  and  the  lesser  cornua,  conical 
in  form,  give  attachment  to  the  stylo-hyoid  liga- 
ments. In  early  age  and  in  the  adult,  the  cornua  are  connected  with  the 
body  by  cartilaginous  surfaces  and  ligamentous  fibres ;  but  in  old  age  they 
become  united  by  bone. 

Development. — By  five  centres,  one  for  the  body,  and  one  for  each 
cornu.  Ossification  commences  in  the  greater  cornua  during  the  last 
month  of  foetal  life,  and  in  the  lesser  cornua  and  body  soon  after  birth. 

Attachment  of  Muscles. — To  eleven  pairs ;  sterno-hyoid,  thyro-hyoid, 
omo-hyoid,  pulley  of  the    digastricus,  stylo-hyoid,   mylo-hyoid,   genio 
hyoid,  genio-hyo-glossus,  hyo-glossus,  lingualis,  and  middle  constrictor 
of  the  pharynx.     It  also  gives  attachment  to  the  stylo-hyoid,  thyro-hyoid, 
and  hyo-epiglottic  ligaments,  and  to  the  thyro-hyoidean  membrane. 

*  The  os  hyoides  seen  from  before.  1.  The  antero-superior,  or  convex  side  of  the 
body.  2.  The  great  cornu  of  the  left  side.  3.  The  lesser  cornu  of  the  same  side.  Th« 
cornua  were  ossified  to  the  body  of  the  bone  in  the  specimen  from  which  this  figure  wa« 
drawn. 


100  STERNUM. 


THORAX    AND   UPPER   EXTREMITY. 

The  bones  of  the  thorax  are  the  sternum  and  ribs ;  and,  of  the  upper 
extremity,  the  clavicle,  scapula,  humerus,  ulna  and  radius,  bones  of  the 
carpus,  metacarpus,  and  phalanges. 

STERNUM. — The  sternum  (fig.  49)  is  situated  in  the  middle  line  of  the 
front  of  the  chest,  and  is  oblique  in  direction,  the  superior  end  lying  within 
a  few  inches  of  the  vertebral  column,  and  the  inferior  being  projected  for- 
wards so  as  to  be  placed  at  a  considerable  distance  from  the  spine.  The 
bone  is  flat  or  slightly  concave  in  front,  and  marked  by  five  transverse 
lines  which  indicate  its  original  subdivision  into  six  pieces.  It  is  convex 
behind,  broad  and  thick  above,  flattened  and  pointed  below,  and  is  divisible 
in  the  adult  into  three  pieces,  superior,  middle,  and  inferior. 

The  superior  piece,  or  manubrium,  is  nearly  quadrilateral ;  it  is  broad 
and  thick  above,  where  it  presents  a  concave  border  (incisura  semilu- 
naris),  and  narrow  at  its  junction  with  the  middle  piece.  At  each  supe- 
rior angle  is  a  deep  articular  depression  (incisura  clavicularis)  for  the 
clavicle,  and  on  either  side  twro  notches,  for  the  articulation  of  the  carti- 
lage of  the  first  rib,  and  one  half  of  the  second. 

The  middle  piece,  or  body,  considerably  longer  than  the  superior,  is 
broad  in  the  middle,  and  somewhat  narrower  at  each  extremity.  It  pre- 
sents at  either  side  six  articular  notches,  for  the  lower  half  of  the  second 
rib,  the  four  next  ribs,  and  the  upper  half  of  the  seventh.  This  piece  is 
sometimes  perforated  by  an  opening  of  various  magnitude,  resulting  from 
arrest  of  development. 

The  inferior  piece  (ensiform  or  xiphoid  cartilage)  is  the  smallest  of  the 
three,  often  merely  cartilaginous,  and  very  various  in  appearance,  being 
sometimes  pointed,  at  other  times  broad  and  thin,  and  at  other  times 
again,  perforated  by  a  round  hole,  or  bifid.  It  presents  a  notch  at 
each  side  for  the  articulation  of  the  lower  half  of  the  cartilage  of  the 
seventh  rib. 

Development. — By  a  variable  number  of  centres,  generally  ten,  namely, 
two  for  the  manubrium  ;  one  (sometimes  two)  for  the  first  piece  of  the 
body,  two  for  each  of  the  remaining  pieces,  and  one  for  the  ensiform  car- 
tilage. Ossification  commences  towards  the  end  of  the  fifth  month  in  the 
manubrium,  the  two  pieces  for  this  part  being  placed  one  above  the  other. 
At  about  the  same  time  the  centres  for  the  first  and  second  pieces  of  the 
body  are  apparent ;  the  centres  for  the  third  piece  of  the  body  appear  a 
few  months  later,  and  those  for  the  fourth  piece  soon  after  birth.  The 
osseous  centre  for  the  ensiform  cartilage  is  so  variable  in  its  advent,  that 
it  may  be  present  at  any  period  between  the  third  and  eighteenth  year. 
The  double  centres  for  the  body  of  the  sternum  are  disposed  side  by  side 
in  pairs,  and  it  is  the  irregular  union  of  these  pairs  in  the  last  three  pieces 
of  the  body  that  gives  rise  to  the  large  aperture  occasionally  seen  in  the 
sternum,  towards  its  lower  part.  Union  of  the  pieces  of  the  sternum 
commences  from  below  and  proceeds  upwards ;  the  fourth  and  the  third 
unite  at  about  puberty,  the  third  and  the  second  between  twenty  and 
twenty-five,  and  the  second  and  the  first  between  twenty-five  and  thirty. 
The  ensiform  appendix  becomes  joined  to  the  body  of  the  sternum  at 
forty  or  fifty  years ;  and  the  manubrium  to  the  body  only  in  very  old  age. 
Two  small  pisiform  pieces  have  been  described  by  Beclard  and  Breschet, 


RIBS TRUE    AND    FALSE. 


101 


Fig.  49.* 


as  being  situated  upon  and  somewhat  behind  each  extremity  of  the  inci- 
sura  semilunaris  of  the  upper  border  of  the  manubrium.  These  pre 
sternal  or  supra-sternal  pieces,  which  are  by  no  means  constant,  appear  at 
about  the  thirty-fifth  year.  Beclard  considers  them  to  be  the  analogue 
of  the  fourchette  of  birds,  and  Breschet  as  the  sternal  ends  of  the  cer- 
vical rib. 

Articulations. — With  sixteen  bones ;  viz.  with  the  clavicle  and  the  seven 
true  ribs,  at  each  side. 

Attachment  of  Muscles.  —  To  nine  pairs  and  one  single  muscle  ;  viz. 
to  the  pectoralis  major,  sterno-mastoid,  sterno-hyoid,  sterno-thyroid,  tri- 
angularis  sterni,  aponeurosis  of  the  obliquus  externus,  internus,  and  trans- 
versalis  muscles,  rectus,  and  diaphragm. 

RIBS. — The  ribs  are  twelve  in  number  at  each  side ;  the  first  seven  are 
connected  with  the  sternum,  and  hence  named  sternal  or  true  ribs ;  the 
remaining  five  are  the  asternal  or  false 
ribs ;  and  the  last  two  shorter  than  the 
rest,  and  free  at  their  extremities,  are 
the  floating  ribs.  The  ribs  increase 
in  length  from  the  first  to  the  eighth, 
whence  they  again  diminish  to  the 
twelfth  ;  in  breadth  they  diminish  gra- 
dually from  the  first  to  the  last,  and 
with  the  exception  of  the  last  two 
are  broader  at  the  anterior  than  at  the 
posterior  end.  The  first  rib  is  hori- 
zontal in  its  direction  ;  all  the  rest  are 
oblique,  so  that  the  anterior  extremity 
falls  considerably  below  the  posterior. 
Each  rib  presents  an  external  and  in- 
ternal surface,  a  superior  and  inferior 
border,  and  two  extremities ;  it  is 
curved  to  correspond  with  the  arch 
of  the  thorax,  and  twisted  upon  itself, 
so  that,  when  laid  on  its  side,  one 
end  is  tilted  up,  while  the  other  rests  upon  the  surface. 

The  external  surface  is  convex,  and  marked  by  the  attachment  of 
muscles;  the  internal  is  flat,  £nd  corresponds  with  the  pleura;  the  superior 
border  is  rounded  ;  and  the  inferior  sharp,  and  grooved  upon  its  inner 
side,  for  the  attachment  of  the  intercostal  muscles,  f  Near  its  vertebral 
extremity,  the  rib  is  suddenly  bent  upon  itself;  and  opposite  the  bend, 
upon  the  external  surface,  is  a  rough  oblique  ridge,  which  gives  attach- 
ment to  a  tendon  of  the  sacro-lumbalis  muscle,  and  is  called  the  angle. 
The  distance  between  the  vertebral  extremity  and  the  angle  increases 
gradually,  from  the  second  to  the  eleventh  rib.  Beyond  the  angle  is  a 

*  An  anterior  view  of  the  thorax.  1.  The  superior  piece  of  the  sternum.  2.  The 
middle  piece.  3.  The  inferior  piece,  or  ensiform  cartilage.  4.  The  first  dorsal  vertebra. 
5.  The  last  dorsal  vertebra.  6.  The  first  rib.  7.  Its  head.  8.  Its  neck,  resting  against 
the  transverse  process  of  the  first  dorsal  vertebra.  9.  Its  tubercle.  10.  The  seventh  or 
last  true  rib.  11.  The  costal  cartilages  of  the  true  ribs.  12.  The  last  two  fabe  ribs  or 
floating  ribs.  13.  The  groove  along  the  lower  border  of  the  rib. 

•f  This  groove  is  commonly  described  as  supporting  the  intercostal  artery,  vein,  and 
nerve,  but  this  is  not  the  case. 

9* 


JOS  COSTAL    CARTILAGES. 

rough  elevation,  the  tubercle;  and  immediately  at  the  base  and  under 
side  of  the  tubercle  a  smooth  surface  for  articulation  with  the  extremity 
of  the  transverse  process  of  the  corresponding  vertebra.  The  vertebral 
end  of  the  rib  is  somewhat  expanded,  and  is  termed  the  head,  and  that 
portion  between  the  head  and  the  tubercle  is  the  neck.  On  the  extremity 
of  the  head  is  an  oval  smooth  surface,  divided  by  a  transverse  ridge  into 
two  facets,  for  articulation  with  two  contiguous  vertebrae.  The  posterior 
surface  of  the  neck  is  rough,  for  the  attachment  of  the  middle  costo-trans- 
verse  ligament ;  and  upon  its  upper  border  is  a  crest,  which  gives  attach- 
ment to  the  anterior  costo-transverse  ligament.  The  sternal  extremity  is 
flattened,  and  presents  an  oval  depression,  into  which  the  costal  cartilage 
is  received. 

The  ribs  that  demand  especial  consideration  are  the  first,  tenth,  eleventh, 
and  twelfth. 

The^rs^  is  the  shortest  rib ;  it  is  broad  and  flat,  and  placed  horizon- 
tally at  the  upper  part  of  the  thorax,  the  surfaces  looking  upwards  and 
downwards,  in  place  of  forwards  and  backwards  as  in  the  other  ribs.  At 
about  the  anterior  third  of  the  upper  surface  of  the  bone,  and  near  its  in- 
ternal border,  is  a  tubercle  which  gives  attachment  to  the  scalenus  anticus 
muscle,  and  immediately  before  and  behind  this  tubercle,  a  shallow  ob- 
lique groove,  the  former  for  the  subclavian  vein,  and  the  latter  for  the 
subclavian  artery.  Near  the  posterior  extremity  of  the  bone  is  a  thick  and 
prominent  tubercle,  with  a  smooth  articular  surface  for  the  transverse  pro- 
cess of  the  first  dorsal  vertebra.  There  is  no  angle.  Beyond  the  tuber- 
osity  is  a  narrow  constricted  neck ;  and  at  the  extremity,  a  head,  present- 
ing a  single  articular  surface.  The  second  rib  approaches  in  some  of  its 
characters  to  the  first. 

The  tenth  rib  has  a  single  articular  surface  on  its  head. 

The  eleventh  and  twelfth  have  each  a  single  articular  surface  on  the 
head,  no  neck  or  tubercle,  and  are  pointed  at  the  free  extremity.  The 
eleventh  has  a  slight  ridge,  representing  the  angle,  and  ^  shallow  groove 
on  the  lower  border ;  the  twelfth  has  neither. 

COSTAL  CARTILAGES. — The  costal  cartilages  serve  to  prolong  the  ribs 
forwards  to  the  anterior  part  of  the  chest,  and  contribute  mainly  to  the 
elasticity  of  the  thorax.  They  are  broad  at  their  attachment  to  the  ribs, 
and  taper  slightly  towards  the  opposite  extremity ;  they  diminish  gradually 
in  breadth  from  the  first  to  the  last ;  in  length  they  increase  from  the  first 
to  the  seventh,  and  then  decrease  to  the  last.  The  cartilages  of  the  first 
two  ribs  are  horizontal  in  direction,  the  rest  incline  more  and  more  up- 
wards. In  advanced  age  the  costal  cartilages  are  more  or  less  converted 
into  bone,  this  change  taking  place  earlier  in  the  male  than  in  the  female. 

The  first  seven  cartilages  articulate  with  the  sternum ;  the  three  next 
with  the  lower  border  of  the  cartilage  immediately  preceding,  while  the 
last  two  lie  free  between  the  abdominal  muscles.  All  the  cartilages  of  the 
false  ribs  terminate  by  pointed  extremities. 

Development. — The  ribs  are  developed  by  three  centres  ;  one  for  the 
central  part,  one  for  the  head,  and  one  for  the  tubercle.  The  last  two 
have  no  centre  for  the  tubercle.  Ossification  commences  in  the  body 
somewhat  before  its  appearance  in  the  vertebrae ;  the  epiphysal  centres  for 
the  head  and  tubercle  appear  between  sixteen  and  twenty,  and  are  conso- 
lidated with  the  rest  of  the  bone  at  twenty-five. 


CLAVICLE SCAPULA.  103 

Articulations. — Each  rib  articulates  with  two  vertebrae,  and  one  costal 
cartilage,  with  the  exception  of  the  first,  tenth,  eleventh,  and  twelfth, 
which  articulate  each  with  a  single  vertebra  only. 

Attachment  of  Muscles. — To  the  ribs  and  their  cartilages  are  attached 
twenty-two  pairs,  and  one  single  muscle.  To  the  cartilages,  the  subcla- 
vius,  sterno-thyroid,  pectoralis  major,  internal  oblique,  rectus,  transversa- 
lis,  diaphragm,  triangularis  sterni,  internal  and  external  intercostals.  To 
the  ribs,  the  intercostal  muscles,  scalenus  anticus,  scalenus  posticus,  pec- 
toralis minor,  serratus  magnus,  obliquus  externus,  obliquus  internus,  latis- 
simus  dorsi,  quadratus  lumborum,  serratus  posticus  superior,  serratus  pos- 
ticus inferior,  sacro-lumbalis,  longissimus  dorsi,  cervicalis  ascendens,  leva- 
tores  costarum,  transversalis,  and  diaphragm. 

CLAVICLE. — The  clavicle  is  a  long  bone  shaped  like  the  italic  letter  f, 
and  extended  across  the  upper  part  of  the  side  of  the  chest  from  the  upper 
piece  of  the  sternum  to  the  point  of  the  shoulder,  where  it  articulates  with 
the  scapula.  In  position  it  is  very  slightly  oblique,  the  sternal  end  being 
somewhat  lower  and  more  anterior  than  the  scapular,  and  the  curves  are 
so  disposed  that  at  the  sternal  end  the  convexity,  and  at  the  scapular  the 
concavity,  is  directed  forwards.  The  sternal  half  of  the  bone  is  rounded 
or  irregularly  quadrilateral,  and  terminates  in  a  broad  articular  surface. 
The  scapular  half  is  flattened  from  above  downwards,  and  broad  at  its 
extremity,  the  articular  surface  occupying  only  part  of  its  extent.  The 
upper  surface  is  smooth  and  convex,  and  partly  subcutaneous ;  while  the 
under  surface  is  rough  and  depressed,  for  the  insertion  of  the  irubclavius 
muscle.  At  the  sternal  extremity  of  the  under  surface  is  a  very  rough 
prominence,  which  gives  attachment  to  the  rhomboid  ligament ;  and  at 
the  other  extremity  a  rough  tubercle  and  ridge,  for  the  coraco-clavicular 
ligament.  The  opening  for  the  nutritious  vessels  is  seen  upon  the  under 
surface  of  the  bone. 

Development. — By  two  centres  ;  one  for  the  shaft  and  one  for  the  sternal 
extremity ;  the  former  appearing  before  any  other  bone  of  the  skeleton, 
the  latter  between  fifteen  and  eighteen. 

Articulations. — With  the  sternum  and  scapula. 

Attachment  of  Muscles. — To  six  ;  the  sterno-mastoid,  trapezius,  pecto- 
ralis major,  deltoid,  subclavius,  and  sterno-hyoid. 

SCAPULA. — The  scapula  is  a  flat  triangular  bone,  situated  upon  the  pos- 
terior aspect  and  side  of  the  thorax  occupying  the  space  from  the  second 
to  the  seventh  rib.  It  is  divisible  into  an  anterior  and  posterior  surface, 
superior,  inferior,  and  posterior  border,  anterior,  superior,  and  inferior 
angle,  and  processes. 

The  anterior  surface  or  subscapular  fossa,  is  concave  and  irregular,  and 
marked  by  several  oblique  ridges  which  have  a  direction  upwards  and 
outwards.  The  whole  concavity  is  occupied  by  the  subscapularis  muscle, 
with  the  exception  of  a  small  triangular  portion  near  the  superior  angle 
The  posterior  surface  or  dorsum  is  convex,  and  unequally  divided  into 
two  portions  by  the  spine  ;  that  portion  above  the  spine  is  the  supra-spin 
ous  fossa ;  and  that  below,  the  infra-spinous  fossa. 

The  superior  border  is  the  shortest  of  the  three :  it  is  thin  and  concave, 
and  terminated  at  one  extremity  by  the  superior  angle,  and  at  the  other  by 
the  coracoid  process.  At  its  inner  termination,  and  formed  partly  by  the 


101 


SCAPULA. 


Fig.  50. 


base  of  the  coracoid  process,  is  the  supra-scapular  notch,  for  the  trans 
mission  of  the  supra-scapular  nerve. 

The  inferior  or  axillary  border  is  thick,  and  marked  by  several  grooves 
and  depressions ;  it  terminates  superiorly  at  the  glenoid  cavity,  and  infe- 
riorly  at  the  inferior  angle.  Immediately  below  the  glenoid  cavity  is  a 
rough  ridge,  which  gives  origin  to  the  long  head  of  the  triceps  muscle 
Upon  the  posterior  surface  of  the  border  is  a  depression  for  the  teres  mi- 
nor ;  and  upon  its  anterior  surface  a  deeper  groove  for  the  teres  major ; 
near  the  inferior  angle  is  a  projecting  lip,  which  increases  the  surface  of 
origin  of  the  latter  muscle. 

The  posterior  border,  or  base,  the  longest  of  the  three,  is  turned  towards; 
the  vertebral  column.  It  is  intermediate  in  thickness  between  the  supe- 
rior and  inferior,  and  convex,  being  considerably  inflected  outwards 
towards  the  superior  angle. 

The  anterior  angle  is  the  thickest  part  of  the  bone,  and  forms  the  head 
of  the  scapula;  it  is  immediately  surrounded  by  a  constricted  portion,  the 

neck.  The  head  presents  a  shallow  pyriform 
articular  surface,  the  glenoid  cavity,  having 
the  pointed  extremity  upwards ;  and  at  its 
apex  is  a  rough  depression,  which  gives  at- 
tachment to  the  long  tendon  of  the  biceps. 
The  superior  angle  is  thin  and  pointed. 
The  inferior  angle  is  thick,  and  smooth  upon 
the  external  surface  for  the  origin  of  the  teres 
major  and  for  a  large  bursa  over  which  the 
upper  border  of  the  latissimus  dorsi  muscle 
plays. 

The  spine  of  the  scapula,  triangular  in 
form,  crosses  the  upper  part  of  its  dorsum ; 
it  commences  at  the  posterior  border  by  a 
smooth  triangular  surface  over  which  the 
trapezius  glides  upon  a  bursa,  and  terminates 
at  the  point  of  the  shoulder  in  the  acromion 
process.  The  upper  border  of  the  spine  is 
rough  and  subcutaneous,  and  gives  attach- 
ment by  two  projecting  lips  to  the  trapezius  and  deltoid  muscles ;  the  sur- 
faces of  the  spine  enter  into  the  formation  of  the  supra  and  infra-spinous 
fossae.  The  nutritious  foramina  of  the  scapula  are  situated  in  the  base  of 
the  spine. 

The  acromion  is  somewhat  triangular  and  flattened  from  above  down- 
wards ;  it  overhangs  the  glenoid  cavity,  the  upper  surface  being  rough 
and  subcutaneous,  the  lower  smooth  and  corresponding  with  the  shoulder- 
joint.  Near  its  extremity,  upon  the  anterior  border,  is  an  oval  articular 
surface,  for  the  end  of  the  clavicle. 

The  coracoid  process  is  a  thick,  round,  and  curved  process  of  bone, 
arising  from  the  upper  part  of  the  neck  of  the  scapula,  and  over  arching 

*  A  posterior  view  of  the  scapula.  1.  The  supra-spinous  fossa.  2.  The  infra-spinous 
fossa.  3.  The  superior  border.  4.  The  supra-scapular  notch.  5.  The  anterior  or  axil- 
lary border.  6.  The  head  of  the  scapula  and  glenoid  cavity.  7.  The  inferior  angle. 
8.  The  neck  of  the  scapula,  the  ridge  opposite  the  number  gives  origin  to  the  long  head 
oi  the  triceps.  9.  The  posterior  border  or  base  of  the  scapula.  10.  The  spine.  11.  The 
triangular  smooth  surface,  over  which  the  tendon  of  the  trapezius  glides.  12.  The  aero 
tnion  process.  13.  One  of  the  nutritious  foramina.  14.  The  caracoid  process. 


HUMERUS.  105 

the  glenoid  cavity.  It  is  about  two  inches  in  length  and  very  strong ;  it 
gives  attachment  to  several  ligaments  and  muscles. 

Development. — By  six  centres ;  one  for  the  body,  one  for  the  coracoid 
process,  two  for  the  acromion,  one  for  the  inferior  angle,  and  one  for  the 
posterior  border.  The  ossific  centre  for  the  body  appears  in  the  infra- 
spinous  fossa  at  about  the  same  time  with  the  ossification  of  the  vertebrae ; 
for  the  coracoid  process  during  the  first  year ;  the  acromion  process  at 
puberty ;  the  inferior  angle  in  the  fifteenth  year ;  and  the  posterior 
border  at  seventeen  or  eighteen.  Union  between  the  coracoid  process 
and  body  takes  place  during  the  fifteenth  year;  the  bone  is  not  complete 
till  manhood. 

Articulations. — With  the  clavicle  and  humerus. 

Attachment  of  Muscles. — To  sixteen  ;  by  its  anterior  surface  to  the  sub- 
scapularis  ;  posterior  surface,  supra-spinatus  and  infra-spinatus  ;  superior 
border,  omo-hyoid  ;  posterior  border,  levator  anguli  scapulae,  rhomboideus 
minor,  rhomboideus  major,  and  serratus  magnus ;  anterior  border,  long 
head  of  the  triceps,  teres  minor,  and  teres  major ;  upper  angle  of  the 
glenoid  cavity,  to  the  long  tendon  of  the  biceps ;  spine  and  acromion  to 
the  trapezius  and  deltoid ;  coracoid  process,  to  the  pectoralis  minor,  short 
head  of  the  biceps,  and  coraco-brachialis.  The  ligaments  attached  to  the 
coracoid  process  are,  the  coracoid,  coraco-clavicular,  and  coraco-humeral, 
and  the  costo-coracoid  membrane. 

HUMERUS. — The  humerus  is  a  long  bone  divisible  into  a  shaft  and  two 
extremities. 

The  superior  extremity  presents  a  rounded  head;  a  constriction  imme- 
diately around  the  base  of  the  head,  the  neck;  a  greater  and  a  lesser 
tuberosity.  The  greater  tuberosity  is  situated  most  externally,  and  is 
separated  from  the  lesser  by  a  vertical  furrow,  the  bicipital  groove,  which 
lodges  the  long  tendon  of  the  biceps.  The  edges  of  this  groove  below 
the  head  of  the  bone  are  raised  and  rough,  and  are  called  the  anterior  and 
posterior  bicipital  ridge  ;  the  former  serves  for  the  insertion  of  the  pecto- 
ralis major  muscle,  and  the  latter  of  the  latissimus  dorsi  and  teres  major. 

The  constriction  of  the  bone  below  the  tuberosities  is  the  surgical  neck, 
and  is  so  named,  in  contradistinction  to  the  true  neck,  from  being  the 
seat  of  the  accident  called  by  surgical  writers  fracture  of  the  neck  of  the 
humerus. 

The  shaft  of  the  bone  is  prismoid  at  its  upper  part,  and  flattened  from 
before  backwards  below.  Upon  its  outer  side,  at  about  its  middle,  is  ;i 
rough  triangular  eminence,  which  gives  insertion  to  the  deltoid  ;  and  im 
mediately  on  each  side  of  this  eminence  is  a  smooth  depression,  corres- 
ponding with  the  two  heads  of  the  brachialis  anticus.  Upon  the  innei 
side  of  the  middle  of  the  shaft  is  a  ridge,  for  the  attachment  of  the  coraco 
brachialis  muscle ;  and  behind,  an  oblique  and  shallow  groove,  which 
lodges  the  musculo-spiral  nerve  and  superior  profunda  artery.  The 
foramen  for  the  medullary  vessels  is  situated  upon  the  inner  surface  of  the 
shaft  of  the  bone  a  little  below  the  coraco-brachial  ridge ;  it  is  directed 
downwards. 

The  lower  extremity  is  flattened  from  before  backwards,  and  is  termi 
nated  inferiorly  by  a  long  articular  surface,  divided  into  two  parts  by  an 
elevated  ridge.  The  external  portion  of  the  articular  surface  is  a  rounded 
protuberance,  eminentia  capitata,  which  articulates  with  the  cup-shaped 


106 


ULNA. 


Fig.  51.»  depression  on  the  head  of  the  radius ;  the  internal  portion 
is  a  concave  and  pulley-like  surface,  trochlea,  which  arti- 
culates with  the  ulna.  Projecting  beyond  the  articular 
surface  on  each  side  are  the  external  and  internal  condyles, 
the  latter  being  considerably  the  longer  ;  and  running  up- 
wards from  the  condyles  upon  the  borders  of  the  bone  are 
the  condyloid  ridges,  of  which  the  external  is  the  most 
prominent.  Immediately  in  front  of  the  trochlea  is  a 
small  depression  for  receiving  the  coronoid  process  of  the 
ulna  during  flexion  of  the  fore-arm  ;  and  immediately  be  - 
hind  it  a  large  and  deep  fossa,  for  containing  the  olecra- 
non  process  in  extension. 

Development. — By  seven  centres  ;  one  for  the  shaft,  one 
for  the  head,  one  for  the  tuberosities,  one  for  the  eminen- 
tia  capitata,  one  for  the  trochlea,  and  one  for  each  con- 
dyle,  the  internal  preceding  the  external.  Ossification 
commences  in  the  diaphysis  of  the  humerus  soon  after  the 
clavicle  ;  in  the  head  and  tuberosities,  during  the  second 
,(,  and  third  years  of  infantile  life  ;  in  the  eminentia  capitata 
and  trochlea  during  the  third  and  sixth  years  ;  and  in  the 
condyles  during  the  twelfth  and  fifteenth.  The  entire 
bone  is  consolidated  at  twenty. 

Articulations.  —  With  the  glenoid  cavity  of  the  sca- 
pula, and  with  the  ulna  and  radius. 

Attachment  of  Muscles. — To  twenty-four ;  by  the  greater  tuberosity  to 
the  supra-spinatus,  infra-spinatus,  and  teres  minor ;  lesser  tuberosity,  sub- 
scapularis ;  anterior  bicipital  ridge,  pectoralis  major ;  posterior  bicipital 
ridge  and  groove,  teres  major  and  latissimus  dorsi ;  shaft,  external  and 
internal  heads  of  the  triceps,  deltoid,  coraco-brachialis,  and  brachialis 
anticus ;  external  condyloid  ridge  and  condyle  (condylus  extensorius), 
extensors  and  supinators  of  the  fore-arm,  viz.  supinator  longus,  extensor 
carpi  radialis  longior,  extensor  carpi  radialis  brevior,  extensor  communis 
digitorum,  extensor  minimi  digiti,  extensor  carpi  ulnaris,  anconeus,  and 
supinator  brevis  ;  internal  condyle  (condylus  flexorius),  flexors  and  one 
pronator,  viz.  pronator  radii  teres,  flexor  carpi  radialis,  palmaris  longus, 
flexor  sublimis  digitorum,  and  flexor  carpi  ulnaris. 

ULNA. — The  ulna  is  a  long  bone,  divisible  into  a  shaft  and  two  extre- 
mities. The  upper  extremity  is  large,  and  forms  principally  the  articula- 
tion of  the  elbow  ;  while  the  lower  extremity  is  small,  and  excluded  from 
the  wrist-joint  by  an  inter-articular  fibre-cartilage. 

The  superior  extremity  presents  a  semilunar  concavity  of  large  size,  the 
greater  sigmoid  notch,  for  articulation  with  the  humerus ;  and  upon  the 
outer  side  a  lesser  sigmoid  notch,  which  articulates  with  the  head  of  the 
radius.  Bounding  the  greater  sigmoid  notch  posteriorly  is  the  olecranon 
process ;  and  overhanging  it  in  front,  a  pointed  eminence  with  a  rough 

*  The  humerus  of  the  right  side;  its  anterior  surface.  1.  The  shaft  of  the  bone.  2. 
The  head.  3  The  anatomical  neck.  4.  The  greater  tuberosity.  5.  The  lesser  tube- 
rof-itv.  6.  Tne  bicipital  groove.  7.  The  anterior  bicipital  ridge.  8.  The  posti-nor 
bicipital  ridge.  9.  The  rough  surface  into  which  the  deltoid  is  inserted.  30.  The  nu- 
tritious foramen.  11  The  eminentia  capitata.  12.  The  troehlea.  13.  The  external 
condyle.  14.  The  internal  condyle.  15.  The  external  condyloid  ridge.  16.  The  inter 
nal  condyioid  ridge.  17.  The  fossa  for  the  coronoid  process  of  the  ulna. 


RADIUS.  107 

triangular  base,  the  coronoid  process.  Behind  the  lesser  sigmoid  notch, 
and  extending  downwards  on  the  side  of  the  olecranon,  is  a  triangular 
uneven  surface,  for  the  anconeus  muscle  ;  and  upon  the  posterior  surface 
of  the  olecranon  a  smooth  triangular  surface,  which  is  subcutaneous. 

The  shaft  is  prismoid  in  form,  and  presents  three  surfaces,  anterior, 
posterior,  and  internal ;  and  three  borders.  The  anterior  surface  is  occu- 
pied by  the  flexor  profundis  digitorum  for  the  upper  three-iburths  of  its 
extent ;  and  below  by  a  depression,  for  the  pronator  quadratus  muscle. 
A  little  above  its  middle  is  the  nutritious  foramen,  which  is  directed  up- 
wards. Upon  the  posterior  surface  at  the  upper  part  of  the  bone  is  the 
*xiangular  uneven  depression  for  the  anconeus  muscle,  bounded  inferiorly 
by  an  oblique  ridge  which  runs  downwards  from  the  posterior  extremity 
of  the  lesser  sigmoid  notch.  Below  the  ridge  the  surface  is  marked  into 
several  grooves,  for  the  attachment  of  the  extensor  ossis  metacarpi,  exten- 
sor secundi  internodii,  and  extensor  indicis  muscle.  The  internal  surface 
is  covered  in  for  the  greater  part  of  its  extent  by  the  flexor  profundis  digi- 
torum. The  anterior  border  is  rounded,  and  gives  origin  by  its  lower 
fourth  to  the  pronator  quadratus ;  the  posterior  is  more  prominent,  and 
affords  attachment  to  the  flexor  carpi  ulnaris  and  extensor  carpi  ulnaris. 
At  its  upper  extremity  it  expands  into  the  triangular  subcutaneous  surface 
of  the  olecranon.  The  external  or  radial  border  is  sharp  and  prominent, 
for  the  attachment  of  the  interosseous  membrane. 

The  lower  extremity  terminates  in  a  small  rounded  head,  capitulum 
ulna,  from  the  side  of  which  projects  the  styloid  process.  The  latter  pre- 
sents a  deep  notch  at  its  base  for  the  attachment  of  the  apex  of  the  trian- 
gular interarticular  cartilage,  and  by  its  point  gives  attachment  to  the 
internal  lateral  ligament.  Upon  the  posterior  surface  of  the  head  is  a 
groove,  for  the  tendon  of  the  extensor  carpi  ulnaris ;  and  upon  the  side 
opposite  to  the  styloid  process  a  smooth  surface,  for  articulation  with  the 
side  of  the  radius. 

Development. — By  three  centres ;  one  for  the  shaft,  one  for  the  inferior 
extremity,  and  one  for  the  olecranon.  Ossification  commences  in  the 
ulna  shortly  after  the  humerus  and  radius :  the  two  ends  of  the  bone  are 
cartilaginous  at  birth.  The  centre  for  the  lower  end  appears  at  about  the 
fifth,  and  that  for  the  olecranon  about  the  seventh  year.  The  bone  is 
completed  at  about  the  twentieth  year. 

Articulations. — With  two  bones  ;  the  humerus  and  radius ;  it  is  sepa- 
rated from  the  cuneiform  bone  of  the  carpus  by  the  triangular  interarticular 
cartilage. 

Attachment  of  Muscles. — To  twelve  ;  by  the  olecranon,  to  the  triceps 
extensor  cubiti,  one  head  of  the  flexor  carpi  ulnaris,  and  the  anconeus ; 
by  the  coronoid  process,  to  the  brachialis  anticus,  pronator  radii  teres, 
flexor  sublimis  digitorum,  and  flexor  profundus  digitorum ;  by  the  shaft, 
to  the  flexor  profundus  digitorum,  flexor  carpi  ulnaris,  pronator  quadratus, 
anconeus,  extensor  carpi  ulnaris,  extensor  ossis  metacarpi  pollicis,  extensor 
secundi  internodii  pollicis,  and  extensor  indicis. 

RADIUS. — The  radius  is  the  rotatory  bone  of  the  fore-arm ;  it  is  divisible 
into  a  shaft  and  two  extremities :  unlike  the  ulna,  its  upper  extremity  is 
small,  and  merely  accessory  to  the  formation  of  the  elbow-joint;  while  the 
lower  extremity  is  large,  and  forms  almost  solely  the  joint  of  the  wrist. 

The  superior  extremity,  presents  a  rounded  head,  depressed  upon  it* 


108 


RADIUS. 


Fig  52« 


upper  surface  into  a  shallow  cup.  Around  the  margin  ot 
the  head  is  a  smooth  articular  surface,  which  is  broad  on 
the  inner  side,  where  it  articulates  with  the  lesser  sigmoid 
notch  of  the  ulna,  and  narrow  in  the  rest  of  its  circumfer- 
ence, to  p  ay  in  the  orbicular  ligament.  Beneath  the  head 
is  a  round  constricted  neck ;  and  beneath  the  neck,  on  its 
internal  aspect,  a  prominent  process,  .the  tuberosity.  The 
surface  of  the  tuberosity  is  partly  smooth,  and  partly  rough ; 
rough  below,  where  it  receives  the  attachment  of  the  ten- 
don of  the  biceps ;  and  smooth  above,  where  a  bursa  is 
interposed  between  the  tendon  and  the  bone. 

The  shaft  of  the  bone  is  prismoid,  and  presents  three 
surfaces.  The  anterior  surface  is  somewhat  concave  su- 
periorly, where  it  lodges  the  flexor  longus  pollicis ;  and 
flat  below,  where  it  supports  the  pronator  quadratus.  At 
about  the  upper  third  of  this  surface  is  the  nutritious  fora- 
men, which  is  directed  upwards.  The  posterior  surface 
is  round  above,  where  it  supports  the  supinator  brevis 
muscle,  and  marked  by  several  shallow  oblique  grooves 
below,  which  afford  attachment  to  the  extensor  muscles 
of  the  thumb.  The  external  surface  is  rounded  and  con- 
vex, and  marked  by  an  oblique  ridge,  which  extends  from 
the  tuberosity  to  the  styloid  process  at  the  lower  extremity 
of  the  bone.  Upon  the  inner  margin  of  the  bone  is  a  sharp  and  prominent 
crest,  which  gives  attachment  to  the  interosseous  membrane.  The  lower 
extremity  of  the  radius  is  broad  and  triangular,  and  provided  with  two  ar- 
ticular surfaces ;  one  at  the  side  of  the  bone,  which  is  concave  to  receive 
the  rounded  head  of  the  ulna ;  the  other  at  the  extremity,  and  marked  by 
a  slight  ridge  into  two  facets,  one  external  and  triangular,  corresponding 
with  the  scaphoid;  the  other  square,  with  the  semilunar  bone.  Upon  the 
outer  side  of  the  extremity  is  a  strong  conical  projection,  the  styloid  process, 
which  gives  attachment  by  its  base  to  the  tendon  of  the  supinator  longus, 
and  by  its  apex  to  the  external  lateral  ligament  of  the  wrist  joint.  The 
inner  edge  of  the  articular  surface  affords  attachment  to  the  base  of  the 
inter-articular  cartilage  of  the  ulna. 

Immediately  in  front  of  the  styloid  process  is  a  groove,  which  lodges 
the  tendons  of  the  extensor  ossis  metacarpi  pollicis,  and  extensor  primi 
internodi^ ;  and  behind  the  process  a  broader  groove,  for  the  tendons  of 
the  extensor  carpi  radialis  longior  and  brevior,  and  extensor  secundi  inter- 
Iiodii ;  behind  this  is  a  prominent  ridge,  and  a  deep  and  narrow  groove, 
for  the  tendon  of  the  extensor  indicis ;  and  still  farther  back,  part  of  a 
broad  groove,  completed  by  the  ulna,  for  the  tendons  of  the  extensoi 
communis  digitorum. 

Development. — By  three  centres ;  one  for  the  shaft,  and  one  for  each  ex- 
tremity. Ossification  commences  in  the  shaft  soon  after  the  humerus,  and 
before  that  in  the  ulna.  The  inferior  centre  appears  during  the  second 

*  The  two  bones  of  the  fore-arm  seen  from  the  front.  1.  The  shaft  of  the  ulna.  2. 
The  greater  sigmoid  notch.  3.  The  lesser  sigmoid  notch,  with  whwh  the  head  of  the 
radius  is  articulated.  4.  The  olecranon  process.  5.  The  coronoid  process.  6.  The  nu- 
tritious foramen.  7.  The  sharp  ridges  upon  the  two  bones  to  which  the  interosseous 
membrane  is  attached.  8.  The  rapitulum  ulnae.  9.  The  styloid  process.  1Q.  The 
shaft  of  the  radius.  11.  Its  head  surrounded  by  the  smooth  border  for  articulation  with 
the  orbicular  ligament.  12.  The  neck  of  the  radius.  13.  Its  tuberosity.  14.  The  oblique 
line  15.  Tire  lower  extremity  of  the  bone  1C.  Its  styloid  process. 


CARPUS SCAPHOID  AND  SEMILUNAR  BONES.       109 

year,  and  the  superior  about  the  seventh.  The  bone  is  perfected  at 
twenty. 

Articulations. — With  four  bones ;  humerus,  ulna,  scaphoid,  and  semi- 
lunar. 

Attachment  of  Muscles. — To  nine ;  by  the  tuberosity  to  the  biceps ;  by 
the  oblique  ridge  to  the  supinator  brevis,  pronator  radii  teres,  flexor  sub- 
limis  digitorum  and  pronator  quadratus ;  by  the  anterior  surface,  to  the 
flexor  longus  pollicis  and  pronator  quadratus ;  by  the  posterior  surface,  to 
the  extensor  ossis  metacarpi  pollicis,  and  extensor  primi  internodii ;  and 
by  the  styloid  process,  to  the  supinator  longus. 

CARPUS. — The  bones  of  the  carpus  are  eight  in  number ;  they  are  ar- 
ranged in  two  rows.  In  the  first  row,  commencing  from  the  radial  side, 
are  the  os  scaphoides,  semilunare,  cuneiforme,  pisiforme ;  and  in  the  se- 
cond row,  in  the  same  order,  the  os  trapezium,  trapezoides,  os  magnum, 
arid  unciforme. 

The  SCAPHOID  bone  is  named  from  bearing  some  resemblance  to  the 
shape  of  a  boat,  being  broad  at  one  end,  and  narrowed  like  a  prow  at  the 
opposite,  concave  on  one  side,  and  convex  upon  the  other.  It  is,  how- 
ever, more  similar  in  form  to  a  cashew  nut,  flattened  and  concave  upon 
one  side.  If  carefully  examined,  it  will  be  found  to  present  a  convex  and 
a  concave  surface,  a  convex  and  a  concave  border,  a  broad  end,  and  a  nar- 
row and  pointed  extremity,  the  tuberosity. 

To  ascertain  to  which  hand  the  bone  belongs,  let  the  student  hold  it 
horizontally,  so  that  the  convex  surface  may  look  backwards  (i.  e.  towards 
himself),  and  the  convex  border  upwards:  the  broad  extremity  will  indi- 
cate its  appropriate  hand ;  if  it  be  directed  to  the  right,  the  bone  belongs 
to  the  right ;  and  if  to  the  left,  to  the  left  carpus. 

Articulations. — With^ye  bones  ;  by  its  con-  Fis-  53-* 

vex  surface  with  the  radius;  by  its  concave 
surface,  with  the  os  magnum  and  semilunare ; 
and  by  the  extremity  of  its  upper  or  dorsal 
borcter,  with  the  trapezium  and  trapezoides. 

Attachments.  —  By  its  tuberosity  to  the  ab- 
ductor pollicis,  and  anterior  annular  ligament. 

The  SEMILUNAR  bone  may  be  known  by 
having  a  crescentic  concavity,  and  a  some- 
what crescentic  outline.  It  presents  for  exami- 
nation four  articular  surfaces  and  two  extremi- 
ties ;  the  articular  surfaces  are,  one  concave, 
one  convex,  and  two  lateral,  one  lateral  surface 
being  crescentic,  the  other  nearly  circular,  and 
divided  generally  into  two  facets.  The  extre- 
mities are,  one  dorsal,  which  is  quadrilateral,  flat,  and  indented,  for  th 

*  A  diagram  showing  the  dorsal  surface  of  the  bones  of  the  carpus,  with  their  articn 
lations. — The  right  hand.  2.  The  lower  end  of  the  radius.  1.  The  lower  extremity 
of  the  ulna.  3.  The  inter-articular  fibre-cartilage  attached  to  the  styloid  process  of  the 
ulna,  and  to  the  margin  of  the  articular  surface  of  the  radius.  S.  The  scaphoid  bone. 
L.  The  semilunare  articulating  with  five  bones.  C.  The  cuneiforme,  articulating  witli 
three  bones.  P.  The  pisiforme,  articulating  with  the  cuneiforme  only.  T.  The  firsi 
bone  of  the  second  row, — the  trapezium,  articulating  with  four  bones.  T.  The  second 
bone, — the  trapezoides,  articulating  also  with  four  bones.  M.  The  os  magnum  articu 
latirg  with  seven.  U.  The  unciforme,  articulating  with  five. 

10 


1 10  CUNEIFORME — PISIFORME — TRAPEZIUM. 

attachment  of  ligaments;  the  other  palmar,  which  is  convex,  rounded, 
and  of  larger  size. 

To  determine  to  which  hand  it  belongs,  let  the  bone  be  held  perpendi- 
cularly, so  that  the  dorsal  or  flat  extremity  look  upwards,  and  the  convex 
side  backwards  (towards  the  holder).  The  circular  lateral  surface  will 
point  to  the  side  corresponding  with  the  hand  to  which  the  bone  belongs. 

Articulations.  —  With  Jive  bones,  but  occasionally  with  only  four :  by 
its  convex  surface,  with  the  radius ;  by  its  concave  surface,  with  the  os 
magnum ;  by  its  crescentic  lateral  facet,  with  the  scaphoid ;  and  by  the 
circular  surface,  with  the  cuneiform  bone  and  with  the  point  of  the  unci- 
form.  This  surface  is  divided  into  two  parts  by  a  ridge  when  it  articu- 
lates with  the  unciform  as  well  as  with  the  cuneiform  bone. 

The  CUNEIFORM  bone,  although  somewhat  wedge-shaped  in  form,  may 
be  best  distinguished  by  a  circular  and  isolated  facet,  which  articulates 
with  the  pisiform  bone.  It  presents  for  examination  three  surfaces,  a  base, 
and  an  apex.  One  surface  is  very  rough  and  irregular ;  the  opposite  forms 
a  concave  articular  surface,  while  the  third  is  partly  rough  and  partly 
smooth,  and  presents  that  circular  facet  which  is  characteristic  of  the  bone. 
The  base  is  an  articular  surface,  and  the  apex  is  round  and  pointed. 

To  distinguish  its  appropriate  hand,  let  the  base  be  directed  backwards 
and  the  pisiform  facet  upwards ;  the  concave  articular  surface  will  point 
to  the  hand  to  which  the  bone  belongs. 

Articulations. — With  three  bones,  and  with  the  triangular  fibro-cartilage. 
By  the  base,  with  the  semilunare  ;  by  the  concave  surface,  with  the  unci- 
forme ;  by  the  circular  facet,  with  the  pisiforme ;  and  by  the  superior  angle 
of  the  rough  surface,  with  the  fibro-cartilage. 

The  PISIFORM  bone  maybe  recognised  by  its  small  size,  and  by  possess- 
ing a  singular  articular  facet.  If  it  be  examined  carefully  it  will  be  ob- 
served to  present  four  sides  and  two  extremities ;  one  side  is  articular, 
the  smooth  facet  approaching  nearer  to  the  superior  than  the  inferior  ex- 
tremity. The  side  opposite  to  this  is  rounded,  and  the  remaining  sides 
are,  one  slightly  concave,  the  other  slightly  convex. 

If  the  bone  be  held  so  that  the  articular  facet  shall  look  downwards  and 
the  extremity  which  overhangs  the  articular  facet  forwards,  the  concave 
side  will  point  to  the  hand  to  which  it  belongs. 

Articulations. — With  the  cuneiform  bone  only. 

Attachments.  —  To  two  muscles,  the  flexor  carpi  ulnaris,  and  abductor 
minimi  digiti ;  and  to  the  anterior  annular  ligament. 

The  TRAPEZIUM  (os  multangulum  majus)  is  too  irregular  in  form  to  be 
compared  to  any  known  object ;  it  may  be  distinguished  by  a  deep 
groove,  for  the  tendon  of  the  flexor  carpi  radialis  muscle.  It  is  somewhat 
compressed,  and  may  be  divided  into  twro  surfaces  which  are  smooth  and 
articular,  and  three  rough  borders.  One  of  the  articular  surfaces  is  oval, 
concave  in  one  direction,  and  convex  in  the  other  (saddle-seat  shaped) ; 
the  other  is  marked  into  three  facets.  One  of  the  borders  presents  the 
groove  for  the  tendon  of  the  flexor  carpi  radialis,  which  is  surmounted  by 
a  prominent  tubercle  for  the  attachment  of  the  annular  ligament ;  the  other 
two  borders  are  rough  and  form  the  outer  side  of  the  carpus.  The  grooved 
border  is  narrow  at  one  extremity  and  broad  at  the  other,  where  it  pre- 
sents the  groove  and  tubercle. 

If  the  bone  be  held  so  that  the  grooved  border  look  upwards  while  the 
•«pex  of  this  border  be  directed  forwards,  and  the  base  with  the  tubercle 


TRAPEZOIDES OS    MAGNUM. 


11] 


oackwards,  the  concavo-convex  surface  will  point  to  the  hand  to  which 
the  bone  belongs. 

Articulations. — Withybwr  bones ;  by  the  concavo-convex  surface,  with 
the  metacarpal  bone  of  the  thumb ;  and  by  the  three  facets  of  the  other 
articular  surface,  with  the  scaphoid,  trapezoid,  and  second  metacarpal 
bone. 

Attachments. — To  two  muscles,  abductor  pollicis  and  flexor  ossis  meta- 
carpi ;  and  by  the  tubercle,  to  the  annular  ligament. 

The  TRAPEZOIDES  (os  multangulum  minus)  is  a  small,  oblong,  and 
quadrilateral  bone,  bent  near  its  middle  upon  itself  (bean-shaped).  It 
presents  four  articular  surfaces  and  two  extremities.  One  of  the  surfaces 
is  concavo-convex^  i.  e.  concave  in  one  direction,  and  convex  in  the  other; 
another,  contiguous  to  the  preceding,  is  concave,  so  as  to  be  almost  angu- 
lar in  the  middle,  and  is  often  marked  by  a  small  rough  depression,  for 
an  interosseous  ligament ;  the  two  remaining  sides  are  flat,  and  present 
nothing  remarkable.  One  of  the  two  extremities  is  broad  and  of  large 
size,  the  dorsal ;  the  other,  or  palmar ,  is  small  and  rough. 

If  the  bone  be  held  perpendicularly,  so  that  the  broad  extremity  be  up- 
wards, and  the  concavo-convex  surface  forwards,  the  angular  concave 
surface  will  point  to  the  hand  to  which  the  bone  belongs. 

Articulations. — With  four  bones;  by  the  concavo-convex  surface,  with 
the  second  metacarpal  bone ;  by  the  angular  concave  surface,  with  the  os 
magnum  ;  and  by  the  other  two  surfaces,  with  the  trapezium  and  scaphoid. 

Attachments. — To  the  flexor  brevis  pollicis  muscle. 

The  Os  MAGNUM  (capitatum)  is  the  largest  bone  of  the  carpus,  and  is 
divisible  into  a  body  and  head.  The  head  is  round  for  the  greater  part 
of  its  extent,  but  is  flattened  on  one  side.  The 
body  is  irregularly  quadrilateral,  and  presents  four 
sides  and  a  smooth  extremity.  Two  of  the  sides 
are  rough,  the  one  being  square  and  flat,  the 
dorsal ;  the  other  rounded  and  prominent,  the 
palmar ;  the  other  two  sides  are  articular,  the 
one  being  concave,  the  other  convex.  The  ex- 
tremity is  a  triangular  articular  surface,  divided 
into  three  facets. 

If  the  bone  be  held  perpendicularly,  so  that 
the  articular  extremity  look  upwards  and  the 
broad  dorsal  surface  backwards  (towards  the 
holder),  the  concave  articular  surface  will  point 
to  the  hand  to  which  the  bone  belongs. 

Articulations.  —  With  seven  bones ;  by  the 
rounded  head,  with  the  cup  formed  by  the  sca- 
phoid and  semilunar  bone ;  by  the  side  of  the 
convex  surface,  with  the  trapezoides  ;  by  the 
concave  surface,  with  the  unciforme ;  and  by 
the  extremity,  with  the  second,  third,  and  fourth  metacarpal  bones. 

*  The  hand  viewed  upon  its  anterior  or  palmar  aspect.  1.  The  scaphoid  bone.  2. 
Tin-  semilunare.  3.  The  cuneiforme.  4.  The  pisiforme.  5.  The  trapezium.  6.  Tn« 
groove  in  the  trapezium  that  lodges  the  tendou  of  the  flexor  carpi  radialis.  7.  The 
trapezades.  8.  The  os  magnum.  9.  The  unciforme.  10,  10.  The  five  metacarpa' 
bones.  11,  11.  The  first  row  of  phalanges.  12,  12.  The  second  row.  13,  13.  Tho 
third  row,  or  ungiial  phalan^s.  14.  The  first  phalanx  cf  the  thumb.  15.  The  second 
and  Ian  phalanx  of  the  thumb. 


112  UNCIFORME METACARPUS. 

Attachments. — To  the  flexor  brevis  pollicis  muscle. 

The  UNCIFORME  is  a  triangular-shaped  bone,  remarkable  for  a  long  and 
curved  process,  which  projects  from  its  palmar  aspect.  It  presents  five 
surfaces  ; — three  articular,  and  two  free.  One  of  the  articular  surfaces  is 
divided  by  a  slight  ridge  into  two  facets ;  the  other  two  converge,  and 
meet  at  a  flattened  angle.*  One  of  the  free  surfaces,  the  dorsal,  is  rough 
and  triangular ;  the  other,  palmar,  also  triangular,  but  somewhat  smaller, 
gives  origin  to  the  unciform  process. 

If  the  bone  be  held  perpendicularly,  so  that  the  articular  surface  with 
two  facets  look  upwards,  and  the  unciform  process  backwards  (towards 
the  holder),  the  concavity  of  the  unciform  process  will  point  to  the  hand 
to  which  the  bone  belongs. 

Articulations. — Withyit'e  bones  ;  by  the  two  facets  on  its  base,  with  the 
fourth  and  fifth  metacarpal  bones  ;  by  the  two  lateral  articulating  surfaces, 
with  the  os  magnum  and  cuneiforme ;  and  by  the  flattened  angle  of  its 
apex,  with  the  semilunare. 

Attachments. — To  two  muscles,  abductor  minimi  digiti,  and  flexor 
brevis  minimi  digiti ;  and  by  the  hook-shaped  process  to  the  annular  liga- 
ment. 

Development. — The  bones  of  the  carpus  are  each  developed  by  a  single 
centre  ;  they  are  cartilaginous  at  birth.  Ossification  commences  towards 
the  end  of  the  first  year  in  the  os  magnum  and  unciforme ;  at  the  end  of 
the  third  year  in  the  cuneiforme ;  during  the  fifth  year  in  the  trapezium 
and  semilunare;  during  the  eighth,  in  the  scaphoides ;  the  ninth,  in  the 
trapezoides :  and  the  twelfth  in  the  pisiforme.  The  latter  bone  is  the  last 
in  the  skeleton  to  ossify;  it  is,  in  reality,  a  sesamoid  tone  of  the  tendon 
of  the  flexor  carpi  ulnaris. 

The  number  of  articulations  which  each  bone  of  the  carpus  presents 
with  surrounding  bones,  may  be  expressed  in  figures,  which  will  materially 
facilitate  their  recollection;  the  number  for  the  first  row  is  5531,  and  for 
the  second  4475. 

METACARPUS. — The  bones  of  the  metacarpus  are  five  in  number.  They 
are  long  bones,  divisible  into  a  head,  shaft,  and  base. 

The  head  is  rounded  at  the  extremity,  and  flattened  at  ear  h  side,  for  the 
insertion  of  strong  ligaments ;  the  shaft  is  prismoid,  and  marked  deeply 
on  each  side,  for  the  attachment  of  the  interossei  muscles  ;  and  the  base 
is  irregularly  quadrilateral  and  rough,  for  the  insertion  of  tendons  and 
ligaments.  The  base  presents  three  articular  surfaces,  one  at  each  side, 
for  the  adjoining  metacarpal  bones;  and  one  at  the  extremity  for  the 
carpus. 

The  metacarpal  bone  of  the  thumb  is  one-third  shorter  than  the  rest, 
flattened  and  broad  on  its  dorsal  aspect,  and  convex  on  its  palmar  side ; 
the  articular  surface  of  the  head  is  not  so  round  as  that  of  the  other  meta- 
carpal bones ;  and  the  base  has  a  single  concavo-convex  surface,  to  arti- 
culate with  the  similar  surface  of  the  trapezium. 

The  metacarpal  bones  of  the  different  fingers  may  be  distinguished  bv 
certain  obvious  characters.  The  base  of  the  metacarpal  bone  of  the  index 
finger  is  the  largest  of  the  four,  and  presents  four  articular  surfaces.  That 
of  the  middle  finger  may  be  distinguished  by  a  rounded  projecting  process 

•  When  *he  unciforme  does  not  articulate  with  the  semilunare,  this  angle  is  sharp 


PHALANGES.  113 

upon  the  radial  side  of  its  base,  and  two  small  circular  facets  upon  its 
ulnar  lateral  surface.  The  base  of  the  metacarpal  bone  of  the  ring-finger 
is  small  and  square,  and  has  two  small  circular  facets  to  correspond  with 
those  of  the  middle  metacarpal.  The  metacarpal  bone  of  the  little  finger 
has  only  one  lateral  articular  surface. 

Development. — By  two  centres ;  one  for  the  shaft,  and  one  for  the  digi- 
tal extremity,  with  the  exception  of  the  metacarpal  bone  of  the  thumb,  the 
epiphysis  of  which,  like  that  of  the  phalanges,  occupies  the  carpal  end  of 
the  bone.  Ossification  of  the  metacarpal  bones  commences  in  the  em- 
bryo between  the  tenth  and  twelfth  week,  that  is,  soon  after  the  bones  of 
the  fore-arm.  The  epiphyses  make  their  appearance  at  the  end  of  the 
second,  or  early  in  the  third  year,  and  the  bones  are  completed  at  twenty. 

Articulations. — The  first  with  the  trapezium  ;  second,  with  the  trape- 
zium, trapezoides,  and  os  magnum,  and  with  the  middle  metacarpal 
bone  ;  third,  or  middle,  with  the  os  magnum,  and  adjoining  metacarpal 
bones ;  fourth,  with  the  os  magnum  and  unciforme,  and  with  the  adjoin- 
ing metacarpal  bones ;  and,  fifth,  with  the  unciforme,  and  with  the  meta- 
carpal bone  of  the  ring-finger. 

The  figures  resulting  from  the  number  of  articulations  which  each 
metacarpal  bone  possesses,  taken  from  the  radial  to  the  ulnar  side,  are 
13121. 

Attachment  of  Muscles. — To  the  metacarpal  bone  of  the  thumb,  three, 
the  flexor  ossis  metacarpi,  extensor  ossis  metacarpi,  and  first  dorsal  inter- 
osseous  ;  of  the  index  finger,  five,  the  extensor  carpi  radialis  longior, 
flexor  carpi  radialis,  first  and  second  dorsal  interosseous,  and  first  palmar 
interosseous ;  of  the  middle  finger,  four,  the  extensor  carpi  radialis  bre- 
vior,  adductor  pollicis,  and  second  and  third  dorsal  interosseous ;  of  the 
ring  finger,  three,  the  third  and  fourth  dorsal  interosseous,  and  second 
palmar ;  and  of  the  little  finger,  four,  extensor  carpi  ulnaris,  adductor 
minimi  digiti,  fourth  dorsal,  and  third  palmar  interosseous. 

PHALANGES. — The  phalanges  are  the  bones  of  the  fingers ;  they  are 
named  from  their  arrangement  in  rows,  and  are  fourteen  in  number,  three 
to  each  finger,  and  two  to  the  thumb.  In  conformation  they  are  long 
bones,  divisible  into  a  shaft,  and  two  extremities. 

The  shaft  is  compressed  from  before  backwards,  convex  on  its  poste- 
rior surface,  and  flat  with  raised  edges  in  front.  The  metacarpal  ex- 
tremity, or  base,  in  the  first  row,  is  a  simple  concave  articular  surface,  that 
in  the  other  two  rows  a  double  concavity,  separated  by  a  slight  ridge. 
The  digital  extremities  of  the  first  and  second  row  present  a  pulley-like 
surface,  concave  in  the  middle,  and  convex  on  each  side.  The  ungual 
extremity  of  the  last  phalanx  is  broad,  rough,  and  expanded  into  a  semi- 
lunar  crest. 

Development. — By  two  centres ;  one  for  the  shaft,  and  one  for  the  base. 
Ossification  commences  first  in  the  third  phalanges,  then  in  the  first,  and 
lastly  in  the  second.  The  period  of  commencement  corresponds  with 
that  of  the  metacarpal  bones.  The  epiphyses  of  the  first  row  appear  dur- 
ing the  third  or  fourth  year,  those  of  the  second  row  during  the  fourth  or 
fifth,  and  of  the  last  during  the  sixth  or  seventh.  The  phalanges  are  per- 
fected by  the  twentieth  year. 

Articulations. — The  first  row,  with  the  metacarpal  bones  and  second 

10*  H 


114 


OS    INNOMINATUM — ILIUM. 


row  of  phalanges  ;  the  second  row,  with  the  first  and  third ;  and  the  third, 
with  the  second  row. 

Attachment  of  Muscles. — To  the  base  of  the  first  phalanx  of  the  thumb 
four  muscles,  abductor  pollicis,  flexor  brevis  pollicis,  adductor  pollicis, 
and  extensor  primi  internodii ;  and  to  the  second  phalanx,  two,  the  flexor 
longus  pollicis,  and  extensor  secundi  internodii.  To  the  first  phalanx  of 
the  second,  third,  and  fourth  fingers,  one  dorsal  and  one  palmar  interos- 
seous,  and  to  the  first  phalanx  of  the  little  finger,  the  abductor  minimi 
digiti,  flexor  brevis  minimi  digiti,  and  one  palmar  interosseous.  To  the 
second  phalanges,  the  flexor  sublimis  and  extensor  communis  digitorum  ; 
and  to  the  last  phalanges,  the  flexor  profundus  and  extensor  cornmunis 
digitorum. 

PELVIS     AND     LOWER     EXTREMITY. 

The  bones  of  the  pelvis  are  the  two  ossa  innominata,  the  sacrum,  and 
the  coccyx ;  and  of  the  lower  extremity,  the  femur,  patella,  tibia  and 
fibula,  tarsus,  metatarsus,  and  phalanges. 

Fig-  55-*  Os  INNOMINATUM. — The  os  inno- 

minatum  (os  coxa)  is  an  irregular 
flat  bone,  consisting  in  the  young 
subject  of  three  parts,  which  meet  at 
the  acetabulum.  Hence  it  is  usually 
described  in  the  adult  as  divisible 
into  three  portions,  ilium,  ischium, 
and  pubes.  The  ilium  is  the  supe- 
rior, broad,  and  expanded  portion 
which  fofms  the  prominence  of  the 
hip,  and  articulates  with  the  sacrum. 
The  ischium  is  the  inferior  and  strong 
part  of  the  bone  on  which  we  sit. 
The  os  pubis  is  that  portion  which 
forms  the  front  of  the  pelvis,  and 
gives  support  to  the  external  organs 
of  generation. 

The  ILIUM  may  be  described  as 
divisible  into  an  internal  and  external 
surface,  a  crest,  and  an  anterior  and  posterior  border. 

The  internal  surface  is  bounded  above  by  the  crest,  below  by  a  promi- 
nent line,  the  linea  ilio-pectinea,  and  before  and  behind  by  the  anterior 
and  posterior  borders ;  it  is  concave  and  smooth  for  the  anterior  two-thirds 
of  its  extent,  and  lodges  the  iliacus  muscle.  The  posterior  third  is  rough, 
for  articulation  with  the  sacrum,  and  is  divided  by  a  deep  groove  into  two 
parts ,  <m  anterio.  or  auricular  portion,  which  is  shaped  like  the  pinna, 

*The  os  innominatum  of  the  right  side.  1.  The  ilium;  its  external  surface.  2.  The 
ischium.  3.  The  os  pubis.  4.  The  crest  of  the  ilium.  5.  The  superior  curved  line. 
6.  The  inferior  curved  line.  7.  The  surface  for  the  glutens  maxim  us.  8.  The  anterior 
superior  spinons  process.  9.  The  anterior  inferior  spinous  process.  10.  The  posterior 
superior  spinous  process.  11.  The  posterior  inferior  spinous  process.  12.  The  spine 
uf  the  ischium.  13.  The  great  sacro-ischiatic  notch.  14.  The  lesser  sacro-ischiatic 
notch.  15.  The  tuberosity  of  the  ischium,  showing  its  three  facets.  16.  The  ramus  of 
'.he  ischium.  17.  The  body  of  the  os  pubis.  18.  The  ramus  of  the  pubis.  19.  The 
20.  The  foramen  thyroideum. 


ISCHIUM.  115 

and  coated  by  cartilage  in  the  fresh  bone ,  and  a  posterior  portion,  which 
is  very  rough  and  uneven  for  the  attachment  of  interosseous  ligaments. 

The  external  surface  is  uneven,  partly  convex,  and  partly  concave  ;  it 
is  bounded  above  by  the  crest ;  below  by  a  prominent  arch,  which  forms 
lie  upper  segment  of  the  acetabulum  ,  and  before  and  behind,  by  the 
anterior  and  posterior  borders.  Crossing  this  surface  in  an  arched  direc- 
tion, from  the  anterior  extremity  of  the  crest  to  a  notch  upon  the  lower 
part  of  the  posterior  border,  is  a  groove,  which  lodges  the  gluteal  vessels 
and  nerve,  the  superior  curved  line ;  and  below  this,  at  a  short  distance,  a 
rough  ridge,  the  inferior  curved  line.  The  surface  included  between  the 
superior  curved  line  and  the  crest,  gives  origin  to  the  gluteus  medius 
muscle  ;  that  between  the  curved  lines,  to  the  gluteus  minimus ;  and  the 
rough  interval  between  the  inferior  curved  line  and  the  arch  of  the  aceta- 
bulum, to  one  head  of  the  rectus.  The  posterior  sixth  of  this  surface  is 
rough  and  raised,  and  gives  origin  to  part  of  the  gluteus  maximus. 

The  crest  of  the  ilium  is  arched  and  curved  in  its  direction  like  the 
italic  lettery,  being  bent  inwards  at  its  anterior  termination,  and  outwards 
towards  the  posterior.  It  is  broad  for  the  attachment  of  three  planes  of 
muscles,  which  are  connected  with  its  external  and  internal  borders  or 'lips, 
and  with  the  intermediate  space. 

The  anterior  border  is  marked  by  two  projections,  the  anterior  superior 
spinous  process,  which  is  the  anterior  termination  of  the  crest,  and  the 
anterior  inferior  spinous  process  ;  the  two  processes  being  separated  by  a 
notch  for  the  attachment  of  the  sartorius  muscle.  This  border  terminates 
inferiorly  in  the  lip  of  the  acetabulum.  The  posterior  border  also  presents 
two  projections,  the  posterior  superior  and  the  posterior  inferior  spinous 
process,  separated  by  a  notch.  Inferiorly  this  border  is  broad  and  arched, 
and  forms  the  upper  part  of  the  great  sacro-ischiatic  notch. 

The  ISCHIUM  is  divisible  into  a  thick  and  solid  portion,  the  body,  and 
into  a  thin  and  ascending  part,  the  ramus ;  it  may  be  considered  also,  for 
convenience  of  description,  as  presenting  an  external  and  internal  surface, 
and  three  borders,  posterior,  inferior,  and  superior. 

The  external  surface  is  rough  and  uneven,  for  the  attachment  of  muscles ; 
and  broad  and  smooth  above,  where  it  enters  into  the  formation  of  the 
acetabulum.  Below  the  inferior  lip  of  the  acetabulum  is  a  notch,  which 
lodges  the  obturator  externus  muscle  in  its  passage  outwards  to  the  tro- 
chanteric  fossa  of  the  femur.  The  internal  surface  is  smooth,  and  some- 
what encroached  upon  at  its  posterior  border  by  the  spine. 

The  posterior  border  of  the  ischium  presents  towards  its  middle  a  re- 
markable projection,  the  spine.  Immediately  above  the  spine  is  a  notch 
of  large  size,  the  great  sacro-ischiatic,  and  below  the  spine  the  lesser  sacro- 
ischiatic  notch ;  the  former  being  converted  into  a  foramen  by  the  lesser 
sacro-ischiatic  ligament,  gives  passage  to  the  pyriformis  muscle,  the  gluteal 
vessels  and  nerve,  pudic  vessels  and  nerve,  and  ischiatic  vessels  and  nerve; 
and  the  lesser,  completed  by  the  great  sacro-ischiatic  ligament,  to  the 
obturator  internus  muscle,  and  to  the  internal  pudic  vessels  and  nerve. 
The  inferior  border  is  thick  and  broad,  and  is  called  the  tuberosity.  The 
surface  of  the  tuberosity  is  divided  into  three  facets ;  one  anterior,  which 
is  rough  for  the  origin  of  the  semi-membranosus ;  and  two  posterior,  which 
are  smooth,  and  separated  by  a  slight  ridge  for  the  semi-tendinosus  and 
biceps  muscle.  The  inner  margin  of  the  tuberosity  is  bounded  by  a  sharp 
ridge,  which  gives  attachment  to  a  prolongation  of  the  great  sacro-ischiatic 


116  OS    PUBIS. 

ligament,  and  the  outer  margin  by  a  prominent  ridge,  from  which  the 
quadratus  femoris  muscle  arises.  The  superior  border  of  the  ischium  is 
thin,  and  forms  the  lower  circumference  of  the  obturator  foramen.  The 
ramus  of  the  ischium  is  continuous  with  the  ramus  of  the  pubis,  and  is 
slightly  everted. 

The  Os  PUBIS  is  divided  into  a  horizontal  portion  or  body  (horizonta 
ramus  of  Albinus),  and  a  descending  portion  or  ramus ;  it  presents  fo 
examination  an  external  and  internal  surface,  a  superior  and  inferior  bor 
der,  and  symphysis. 

The  external  surface  is  rough,  for  the  attachment  of  muscles ;  and  pro- 
minent at  its  outer  extremity,  where  it  forms  part  of  the  acetabulum.  The 
internal  surface  is  smooth,  and  enters  into  the  formation  of  the  cavity  of 
the  pelvis.  The  superior  border  is  marked  by  a  rough  ridge,  the  crest , 
the  inner  termination  of  the  crest  is  the  angle;  and  the  outer  end,  the  spine 
or  tubercle.  Running  outwards  from  the  spine  is  a  sharp  ridge,  the  pecti- 
neal  line,  or  linea  ilio-pectinea,  which  marks  the  brim  of  the  true  pelvis. 
In  front  of  the  pectineal  line  is  a  smooth  depression,  which  supports  the 
femoral  artery  and  vein,  and  a  little  more  externally  an  elevated  promi- 
nence, the  ilio-pectineal  eminence,  which  divides  the  surface  for  the  femoral 
vessels,  from  another  depression  which  overhangs  the  acetabulum,  and 
lodges  the  psoas  and  iliacus  muscles.  The  ilio-pectineal  eminence  more- 
over marks  the  junction  of  the  pubes  with  the  ilium.  The  inferior  border 
is  broad  and  deeply  grooved,  for  the  passage  of  the  obturator  vessels  and 
nerve  ;  and  sharp  upon  the  side  of  the  ramus,  to  form  part  of  the  bound- 
ary of  the  obturator  foramen.  The  symphysis  is  the  inner  extremity  of 
the  body  of  the  bone  ;  it  is  oval  and  rough,  for  the  attachment  of  a  liga- 
mentous  structure  analogous  to  the  intervertebral  substance.  The  ramus 
of  the  pubes  descends  obliquely  outwards,  and  is  continuous  with  the 
ramus  of  the  ischium.  The  inner  border  of  the  ramus  forms  with  the 
corresponding  bone  the  arch  of  the  pubes,  and  at  its  inferior  part  is  con- 
siderably everted,  to  afford  attachment  to  the  crus  penis. 

The  acetabulum  (cavitas  cotyloidea)  is  a  deep  cup-shaped  cavity,  situ- 
ated at  the  point  of  union  between  the  ilium,  ischium,  and  pubes ;  a  little 
less  than  two-fifths  being  formed  by  the  ilium,  a  little  more  than  two-fifths 
by  the  ischium,  and  the  remaining  fifth  by  the  pubes.  It  is  bounded  by 
a  deep  rim  or  lip,  which  is  broad  and  strong  above,  where  most  resistance 
is  required,  and  marked  in  front  by  a  deep  notch,  which  is  arched  over 
in  the  fresh  subject  by  a  strong  ligament,  and  transmits  the  nutrient  ves- 
sels into  the  joint.  At  the  bottom  of  the  cup  and  communicating  with  the 
notch,  is  a  deep  and  circular  pit  (fundus  acetabuli)  which  lodges  a  mass 
of  fat,  and  gives  attachment  to  the  broad  extremity  of  the  ligamentum  teres. 

The  obturator  or  thyroid  foramen  is  a  large  oval  interval  between  the 
ischium  and  pubes,  bounded  by  a  narrow  rough  margin,  to  which  a  liga- 
mentous  membrane  is  attached.  The  upper  part  of  the  foramen  is  increased 
in  depth  by  the  groove  in  the  under  surface  of  the  os  pubis  which  lodges 
the  obturator  vessels  and  nerve. 

Development. — By  eight  centres ;  three  principal,  one  for  the  ilium,  one 
Jor  the  ischium,  and  one  for  the  pubes ;  and  five  secondary,  one,  the 
Y-shaped  piece  for  the  interval  between  the  primitive  pieces  in  the  aceta- 
buJum,  one  for  the  crest  of  the  ilium,  one  (not  constant)  for  the  anterior 
and  inferior  spinous  process  of  the  ilium,  one  for  the  tuberosity  of  the 
-£chium3  and  one  (not  constant)  for  the  angle  of  the  os  pubis.  Oss'ification 


PELVIS. 


117 


commences  in  the  primitive  pieces,  immediately  after  that  in  the  vertebrae, 
firstly  in  the  ilium,  then  in  the  ischium,  and  lastly  in  the  pubes ;  the  first 
ossific  deposits  being  situated  near  to  the  future  acetabulum.  At  birth  the 
acetabulum,  the  crest  of  the  ilium,  and  the  ramus  of  the  pubes  and  ischium, 
are  cartilaginous.  The  secondary  centres  appear  at  puberty,  and  the  en- 
tire bone  is  not  completed  until  the  twenty-fifth  year. 

Articulations. — With  three  bones  ;  sacrum,  opposite  innominatum,  and 
femur. 

Attachments  of  Muscles  and  Ligaments . — To  thirty-five  muscles;  to  the 
ilium,  thirteen ;  by  the  outer  lip  of  the  crest,  to  the  obliquus  externus  for 
two-thirds,  and  to  the  latissimus  dorsi  for  one-third  its  length,  and  to  the 
tensor  vagina?  femoris  by  its  anterior  fourth ;  by  the  middle  crest,  to  the 
internal  oblique  for  three-fourths  its  length,  by  the  remaining  fourth  to  the 
erector  spinse ;  by  the  internal  lip,  to  the  transversalis  for  three-fourths, 
and  to  the  quadratus  lumborum  by  the  posterior  part  of  its  middle  third. 
By  the  external  surface,  to  the  gluteus  medius,  minimus  and  maximus, 
and  to  one  head  of  the  rectus  ;  by  the  internal  surface,  to  the  iliacus  ;  and 
by  the  anterior  border  to  the  sartorius,  and  the  other  head  of  the  rectus. 
To  the  ischium,  sixteen ;  by  its  external  surface,  the  adductor  magnus  and 
obturator  externus ;  by  the  internal  surface,  the  obturator  internus  and 
levator  ani ;  by  the  spine,  the  gemellus  superior,  levator  ani,  coccygeus, 
and  lesser  sacro-ischiatic  ligament ;  by  the  tuberosity,  the  biceps,  semi- 
tendinosus,  semi-mem branosus,  gemellus  inferior,  quadratus  femoris,  erec- 
tor penis,  transversus  perinei,  and  great  sacro-ischiatic  ligament ;  and  by 
the  ramus,  the  gracilis,  accelerator  urinae,  and  compressor  urethras.  To 
the  os  pubis,  fifteen;  by  its  upper  border,  the  obliquus  externus,  obliquus 
internus,  transversalis,  rectus,  pyramidalis,  pectineus,  and  psoas  parvus ; 
by  its  external  surface,  the  adductor  longus,  adductor  brevis,  and  gracilis  ; 
by  its  internal  surface,  the  levator  ani,  compressor  urethras,  and  obturator 
internus ;  and  by  the  ramus,  the  adductor  magnus,  and  accelerator  urinse. 

PELVIS. 

The   pelvis  considered  j-;g-  55.* 

as  a  whole  is  divisible  into 
a  false  and  true  pelvis ; 
the  former  is  the  expanded 
portion,  bounded  on  each 
side  by  the  ossa  ilii,  and 
separated  from  the  true 
pelvis  by  the  linea  ilio-pec- 
tinea.  The  true  pelvis  is 
all  that  portion  which  is 
situated  beneath  the  linea 
ilio-pectinea.  This  line 
forms  the  margin  or  brim 
of  the  true  pelvis,  while 
the  included  area  is  called 
the  inlet.  The  form  of  the 
inlet  is  heart-shaped,  ob- 
tusely pointed  in  front  at 

*  A  female  pelvis.     1.  The  last  lumbar  vertebrae.     2,  2.  The  Intervertebrat  substance 
connecting  the  last  Iv.mbar  vertebra  with  the  fourth  and  sacrum.     3.  The  promontory 


113  PELVIS. 

the  symphysis  pubis,  expanded  on  each  side,  and  encroached  upon  be- 
hind by  a  projection  of  the  upper  part  of  the  sacn  m,  which  is  named  the 
promontory.  The  cavity  is  somewhat  encroached  upon  at  each  side  by  a 
smooth  quadrangular  plane  of  bone,  corresponding  with  the  internal  sur- 
face of  the  acetabulum,  and  leading  to  the  spine  of  the  ischium.  In  front 
are  two  fossa  around  the  obturator  foramina,  for  lodging  the  obturator 
internus  muscle,  at  each  side.  The  inferior  termination  of  the  pelvis  is 
very  irregular,  and  is  termed  the  outlet.  It  is  bounded  in  front  by  the 
convergence  of  the  rami  of  the  ischium  and  pubes,  which  constitute  the 
arch  of  the  pubes  ;  on  each  side  by  the  tuberosity  of  the  ischium,  and  by 
two  irregular  fissures  formed  by  the  greater  and  lesser  sacro-ischiatic 
notches ;  and  behind  by  the  lateral  borders  of  the  sacrum,  and  by  the 
coccyx. 

The  pelvis  is  placed  obliquely  with  regard  to  the  trunk  of  the  body,  so 
that  the  inner  surface  of  the  ossa  pubis  is  directed  upwards,  and  would 
support  the  superincumbent  weight  of  the  viscera.  The  base  of  the  sacrum 
rises  nearly  four  inches  above  the  level  of  the  upper  border  of  the  sym- 
physis pubis  and  the  apex  of  the  coccyx,  somewhat  more  than  half  an 
inch  above  its  lower  border.  If  a  line  were  carried  through  the  central 
axis  of  the  inlet,  it  would  impinge  by  one  extremity  against  the  umbilicus, 
and  by  the  other  against  the  middle  of  the  coccyx.  The  axis  of  the  inlet 
is  therefore  directed  downwards  and  backwards,  while  that  of  the  outlet 
points  downwards  and  forwards,  and  corresponds  with  a  line  drawn  from 
the  upper  part  of  the  sacrum,  through  the  centre  of  the  outlet.  The  axis 
of  the  cavity  represents  a  curve,  which  corresponds  very  nearly  with  the 
curve  of  the  sacrum,  the  extremities  being  indicated  by  the  central  points 
of  the  inlet  and  outlet.  A  knowledge  of  the  direction  of  these  axes  is 
most  important  to  the  surgeon,  as  indicating  the  line  in  which  instruments 
should  be  used  in  operations  upon  the  viscera  of  the  pelvis,  and  the  direc- 
tion of  force  in  the  removal  of  calculi  from  the  bladder ;  and  to  the  accou- 
cheur, as  explaining  the  course  taken  by  the  fcetus  during  parturition. 

There  are  certain  striking  differences  between  the  male  and  female  pel- 
vis. In  the  male  the  bones  are  thicker,  stronger,  and  more  solid,  and  the 
cavity  deeper  and  narrower.  In  the  female  the  bones  are  lighter  and 
more  delicate,  the  iliac  fossae  are  large,  and  the  ilia  expanded ;  the  inlet, 
the  outlet,  and  the  cavity,  are  large,  and  the  acetabula  farther  removed 
from  each  other ;  the  cavity  is  shallow,  the  tuberosities  widely  separated, 
the  obturator  foramina  triangular,  and  the  span  of  the  pubic  arch  greater. 
The  precise  diameter  of  the  inlet  and  outlet,  and  the  depth  of  the  cavity, 
are  important  considerations  to  the  accoucheur. 

The  diameters  of  the  inlet  or  brim  are  three :  1.  Antero-posterior,  sacro- 
pubic  or  conjugate ;  2.  transverse  ;  and  3.  oblique.  The  antero-posterior 

of  the  sacrum.  4.  The  anterior  surface  of  the  sacrum,  on  which  its  transverse  lines  and 
foramina  are  seen.  5.  The  tip  of  the  coccyx.  6,  6.  The  iliac  fossse,  forming  the  lateral 
boundaries  of  the  false  pelvis.  7.  The  anterior  superior  spinous  process  of  the  ilium  ; 
left  side.  8.  The  anterior  inferior  spinous  process.  9.  The  acetabulum.  a.  The  notch 
of  the  acetabulum.  6.  The  body  of  the  ischium.  c.  Its  tuberosity.  d.  The  spine  of  the 
ischium  seen  through  the  obturator  foramen,  e.  The  os  pubis.  /.  The  symphysis  pubis. 
g.  The  arch  of  the  pubes.  h.  The  angle  of  the  os  pubis.  i.  The  spine  of  the  pubes  ;  the 
prominent  ridge  between  h  a  -d  i  is  the  crest  of  the  pubes.  k,  k.  The  pectineal  line  of 
the  pubes.  /,  1.  The  ilio-pectineal  line;  m,  m.  the  prolongation  of  this  line  to  the  pro- 
montory of  the  sacrum  The  line  represented  by  h,  i,  k,  k.  I,  I.  and  m,  m.  is  the  brim  of 
the  true  pelvis,  n.  The  ilio-pectineal  eminence,  o.  The  smooth  surface  which  supports 
the  femoral  vessels,  p,  p.  The  great  sacro-ischiatic  notch. 


FEMUR. 


119 


Fig.  57.* 


extends  from  the  symphysis  pubis  to  the  middle  of  the  promontory  of  the 
sacrum,  and  measures  four  inches.  The  transverse  extends  from  the 
middle  of  the  brim  on  one  side  to  the  same  point  on  the  opposite,  and 
measures  five  inches.  The  oblique  extends  from  the  sacro-iliac  symphysis 
on  one  side,  to  the  margin  of  the  brim  corresponding  with  the  acetabulum 
on  the  opposite,  and  also  measures  five  inches. 

The  diameters  of  the  outlet  are  two,  antero-posterior,  and  transverse. 
The  antero-posterior  diameter  extends  from  the  lower  part  of  the  symphy- 
sis pubis  to  the  apex  of  the  coccyx ;  and  the  transverse,  from  the  posterior 
part  of  one  tuberosity  to  the  same  point  on  the  opposite  side  ;  they  both 
measure  four  inches.  The  cavity  of  the  pelvis  measures  in  depth  four 
inches  and  a  half,  posteriorly  ;  three  inches  and  a  half  in  the  middle ;  and 
one  and  a  half  at  the  symphysis  pubis. 

FEMUR. — The  femur,  the  longest  bone  of  the  skeleton,  is  situated  ob- 
liquely in  the  upper  part  of  the  lower  limb,  articulating  by  means  of  its 
head  with  the  acetabulum,  and  inclining  inwards  as  it  descends,  until  it 
almost  meets  its  fellow  of  the  opposite  side  at  the  knee.  In  the  female 
this  obliquity  is  greater  than  in  the  male,  in  consequence  of  the  greater 
breadth  of  the  pelvis.  The  femur  is  divisible  into  a  shaft,  a  superior, 
and  an  inferior  extremity. 

At  the  superior  extremity  is  a  rounded  head,  directed 
upwards  and  inwards,  and  marked  just  below  its  centre 
by  an  oval  depression  for  the  ligamentum  teres.  The 
head  is  supported  by  a  neck,  which  varies  in  length 
and  obliquity  according  to  sex  and  at  various  periods 
of  life,  being  long  and  oblique  in  the  adult  male,  shorter 
and  more  horizontal  in  the  female  and  in  old  age. 
Externally  to  the  neck  is  a  large  process,  the  trochanter 
major,  which  presents  upon  its  anterior  surface  an  oval 
facet,  for  the  attachment  of  the  tendon  of  the  gluteus 
minimus  muscle ;  and  above,  a  double  facet,  for  the 
insertion  of  the  gluteus  medius.  On  its  posterior  side 
is  a  vertical  ridge,  the  linea  quadrati,  for  the  attachment 
of  the  quadratus  femoris  muscle.  Upon  the  inner  side 
of  the  trochanter  major  is  a  deep  pit,  the  trochanteric  or 
digital  fossa,  in  which  are  inserted  the  tendons  of  the 
pyrifortnis,  gemellus  superior  and  inferior,  and  obturator 
externus  and  internus  muscles.  Passing  downwards 
from  the  trochanter  major  in  front  of  the  bone  is  an 
oblique  ridge,  which  forms  the  inferior  boundary  of  the 
neck,  the  anterior  intertrochanteric  line;  and,  behind 
another  oblique  ridge,  the  posterior  intertrochanteric 
line,  which  terminates  in  a  rounded  tubercle  upon  the 
posterior  and  inner  side  of  the  bone,  the  trochanter  mi- 
nor. 

The  shaft  of  the  femur  is  convex  and  rounded  in 

*  The  right  femur,  seen  upon  the  anterior  aspect.  1.  The  shaft.  2.  The  head.  3 
The  neck.  4.  The  great  trochanter.  5.  The  anterior  intertrochanteric  line.  6  The 
lesser  trochanter.  7.  The  external  condyle.  8.  The  internal  condyle.  9.  The  tubero 
shy  for  the  attachment  of  the  external  lateral  ligament.  10.  The  fossa  for  the  teruioii 
of  origin  of  the  popliteus  muscle.  11.  The  tuberosity  for  the  attachment  of  the  inter  nil', 
lateral  ligament. 


Fig.  58.* 


120  FEMUR. 

front,  and  covered  with  muscles ;  and  somewhat  concave  and  raised  into 
a  rough  prominent  ridge  behind,  the  linea  aspera.  The  linea  aspera  near 
the  upper  extremity  of  the  bone  divides  into  three  branches.  The  ante- 
rior branch  is  continued  forwards  in  front  of  the  lesser  trochanter,  and  is 
continuous  with  the  anterior  intertrochanteric  line  ;  the  middle  is  continued 
directly  upwards  into  the  linea  quadrati ;  and  the  posterior,  broad  and 
strongly  marked,  ascends  to  the  base  of  the  trochanter  major.  Towards  the 
lower  extremity  of  the  bone,  the  linea  aspera  divides  into  two  ridges, 
which  descend  to  the  two  condyles,  and  enclose  a  triangular  space  upon 
which  rests  the  popliteal  artery.  The  internal  condyloid  ridge  is  less 
marked  than  the  external,  and  presents  a  broad  and  shallow  groove,  for 
the  passage  of  the  femoral  artery.  The  nutritious  fora- 
men is  situated  in  or  near  the  linea  aspera,  at  about  one- 
third  from  its  upper  extremity,  and  is  directed  obliquely 
from  below  upwards. 

The  lower  extremity  of  the  femur  is  broad  and  por- 
ous, and  divided  by  a  smooth  depression  in  front,  and 
by  a  large  fossa  (fossa  intercondyloidea)  behind  into 
two  condyles. 

The  external  condyle  is  the  broadest  and  most  promi- 
nent, and  the  internal  the  narrowest  and  longest ;  the 
difference  in  length'depending  upon  the  obliquity  of  the 
femur,  in  consequence  of  the  separation  of  the  two 
bones  at  their  upper  extremities  by  the  breadth  of  the 
pelvis.  The  external  condyle  is  marked  upon  its  outer 
side  by  a  prominent  tuberosity,  which  gives  attachment 
to  the  external  lateral  ligament ;  and  immediately  be- 
neath this  is  the  fossa,  which  lodges  the  tendon  of  origin 
of  the  popliteus.  By  the  internal  surface  it  gives  at- 
tachment to  the  anterior  crucial  ligament  of  the  knee- 
joint  ;  and  by  its  upper  and  posterior  part,  to  the  exter- 
V  nal  head  of  the  gastrocnemius  and  to  the  plantaris.  The 

internal  condyle  projects  upon  its  inner  side  into  a  tu- 
berosity, to  which  is  attached  the  internal  lateral  liga- 
ment ;  above  this  tuberosity,  at  the  extremity  of  the  in- 
ternal condyloid  ridge,  is  a  tubercle,  for  the  insertion 
of  the  tendon  of  the  adductor  magnus ;    and  beneath 
the  tubercle,  upon  the  upper  surface  of  the  condyle,  a 
depression,  from  which  the  internal  head  of  the  gastrocnemius  arises. 
The  outer  side  of  the  internal  condyle  is  rough  and  concave,  for  the  at- 
tachment of  the  posterior  crucial  ligament. 

Development. — By  Jive  centres ;  one  for  the  shaft,  one  for  each  extre 
mity,  and  one  for  each  trochanter.    The  femur  is  the  first  of  the  long  bones 
to  show  signs  of  ossification.     In  it,  ossific  matter  is  found  immediately 
after  the  maxilla?  before  the  termination  of  the  second  month  of  embryonic 
life.     The  secondary  deposits  take  place  in  the  following  order,  in  the 

*  A  diagram  of  the  posterior  aspect  of  the  right  femur,  showing  the  lines  of  attach 
ment  of  the  muscles.  The  muscles  attached  to  the  inner  lip  are, — p,  the  pectineus ;  a  b. 
the  adductor  brevis ;  and  a  I,  the  adductor  longus.  The  middle  portion  is  occupied  for 
its  whole  extent  by  a  m,  the  adductor  magnus;  and  is  continuous  superiorly  with  qf 
'he  linea  quadrati,  into  which  the  quadratus  femoris  is  inserted.  The  outer  lip  is  occu 
pied  by  r  r>\,  thr  gluteus  maximus ;  and  6,  the  short  head  of  the  biceps. 


PATELLA TIBIA.  12J 

condyloid  extremity  during  the  last  month  of  fetal  life  ;*  in  the  head  to- 
wards the  end  of  the  first  year ;  in  the  greater  trochanter  between  the 
third  and  the  fourth  year  ;  in  the  lesser  trochanter  between  the  thirteenth 
and  fourteenth.  The  epiphyses  and  apophyses  are  joined  to  the  diaphysis 
in  the  reverse  order  of  their  appearance,  the  junction  commencing  after 
puberty  and  not  being  completed  for  the  condyloid  epiphysis  until  after 
the  twentieth  year. 

Articulations. — With  three  bones ;  with  the  os  innominatum,  tibia,  and 
patella. 

Attachment  of  Muscles. — To  twenty-three ;  by  the  greater  trochanter,  to 
the  gluteus  medius  and  minimus,  pyriformis,  gemellus  superior,  obturator 
internus,  gemellus  inferior,  obturator  externus,  and  quadratus  femoris ;  by 
the  lesser  trochanter,  to  the  common  tendon  of  the  psoas  and  iliacus.  By 
the  linea  aspera,  its  outer  lip,  to  the  vastus  externus,  gluteus  maximus, 
and  short  head  of  the  biceps ;  by  its  inner  lip,  to  the  vastus  internus,  pec- 
tineus,  adductor  brevis,  and  adductor  longus ;  by  its  middle  to  the  ad- 
ductor magnus ;  by  the  anterior  part  6f  the  bone,  to  the  cruraeus  and 
subcrurseus;  by  its  condyles,  to  the  gastrocnernius,  plantaris,  and 
popliteus. 

PATELLA. — The  patella  is  a  sesamoid  bone,  developed  in  the  tendon 
of  the  quadriceps  extensor  muscle,  and  usually  described  as  a  bone  of  the 
lower  extremity.  It  is  heart-shaped  in  figure,  the  broad  side  being  di- 
rected upwards  and  the  apex  downwards,  the  external  surface  convex, 
and  the  internal  divided  by  a  ridge  into  two  smooth  surfaces,  to  articulate 
with  the  condyles  of  the  femur.  The  external  articular  surface  corres- 
ponding with  the  external  condyle  is  the  larger  of  the  two,  and  serves  to 
indicate  the  leg  to  which  the  bone  belongs. 

Development. — By  a  single  centre,  at  about  the  middle  of  the  third 
year. 

Articulations. — With  the  two  condyles  of  the  femur. 

Attachment  of  Muscles. — To  four  ;  the  rectus,  cruneus,  vastus  internus, 
and  vastus  externus,  and  to  the  ligamentum  patellae. 

TIBIA. — The  tibia  is  the  inner  and  larger  bone  of  the  leg ;  it  is  pris- 
moid  in  form,  and  divisible  into  a  shaft,  an  upper  and  lower  extremity. 

The  upper  extremity,  or  head,  is  large,  and  expanded  on  each  side  into 
two  tuberosities.  Upon  their  upper  surface  the  tuberosities  are  smooth,  to 
articulate  with  the  condyles  of  the  femur ;  the  internal  articular  surface 
being  oval  and  oblong,  to  correspond  with  the  internal  condyle  ;  and  the 
external  broad  and  nearly  circular.  Between  the  two  articular  surfaces  is 
a  spinous  process ;  and  in  front  and  behind  the  spinous  process  a  rough 
depression,  giving  attachment  to  the  anterior  and  posterior  crucial  liga- 
ments. Between  the  two  tuberosities,  on  the  front  aspect  of  the  bone,  is 
a  prominent  elevation,  the  tubercle,  for  the  insertion  of  the  ligamentum 
patellae,  and  immediately  above  the  tubercle  a  smooth  facet,  corresponding 
with  the  bursa.  Upon  the  outer  side  of  the  external  tuberosity  is  an  arti- 
cular surface,  for  the  head  of  the  fibula  ;  and  upon  the  posterior  part  of 
the  internal  tuberosity  a  depression,  for  the  insertion  of  the  tendon  of  tht 
semimembranosus  muscle. 

"  Cruveilhier  remarks  that  this  centre  is  so  constant  in  the  last  fortnight  of  fetal  life 
that  it  may  be  regarded  as  an  important  proof  of  the  foetus  having  reached  its  full  term 
11 


122 


FIBULA. 


Fig.  59.* 


The  shaft  of  the  tibia  presents  three  surfaces  ;  internal. 
which  is  subcutaneous  and  superficial ;  external,  which  is 
concave  and  marked  by  a  sharp  ridge,  for  the  insertion 
of  the  interosseous  membrane ;  and  posterior,  grooved, 
for  the  attachment  of  muscles.  Near  the  upper  extremity 
of  the  posterior  surface  is  an  oblique  ridge,  the  popliteal 
line,  for  the  attachment  of  the  fascia  of  the  popliteus  mus 
cle  ;  and  immediately  below  the  oblique  line,  the  nutritious 
canal,  which  is  directed  downwards. 

The  inferior  extremity  of  the  bone  is  somewhat  quadri- 
lateral, and  prolonged  on  its  inner  side  into  a  large  process, 
the  internal  malleolus.  Behind  the  internal  malleolus,  is 
a  broad  and  shallow  groove,  for  lodging  the  tendons  of  the 
tibialis  posticus  and  flexor  longus  digitorum;  and  farther 
outwards  another  groove,  for  the  tendon  of  the  flexor 
longus  pollicis.  Upon  the  outer  side  the  surface  is  con- 
cave and  triangular,  rough  above,  for  the  attachment  of 
the  interosseous  ligament ;  and  smooth  below,  to  articulate 
with  the  fibula.  Upon  the  extremity  of  the  bone  is  a  trian- 
gular smooth  surface,  for  articulating  with  the  astragalus. 

Development. — By  three  centres  ;  one  for  the  shaft,  and 
one  for  each  extremity.  Ossification  commences  in  the 
tibia,  immediately  after  the  femur ;  the  centre  for  the  head 
or  the  bone  appears  soon  after  birth,  and  that  for  the  lower 
extremity  during  the  second  year;  the  latter  is  the  first 
to  join  the  diaphysis.  The  bone  is  not  complete  until  near  the  twenty- 
fifth  year.  Two  occasional  centres  have  sometimes  been  found  in  the  ti- 
bia, one  in  the  tubercle,  the  other  in  the  internal  malleolus. 

.Articulations. — With  three  bones ;  femur,  fibula,  and  astragalus. 
Attachment  of  Muscles. — To  ten;  by  the  internal  tuberosity,  to  the  sar- 
torius,  gracilis,  semitendinosus,  and  semimembranosus ;  by  the  external 
tuberosity,  to  the  tibialis  anticus  and  extensor  longus  digitorum  ;  by  the 
tubercle,  to  the  ligamentum  patella? ;  by  the  external  surface  of  the  shaft, 
to  the  tibialis  anticus  ;  and  by  the  posterior  surface,  to  the  popliteus,  soleus, 
flexor  longus  digitorum,  and  tibialis  posticus. 

FIBULA. — The  fibula  (*e£ovY],  a  brooch,  from  its  resemblance,  in  con- 
junction with  the  tibia,  to  the  pin  of  an  ancient  brooch)  is  the  outer  and 
smaller  bone  of  the  leg;  it  is  long  and  slender  in  figure,  prismoid  in  shape, 
and,  like  other  long  bones,  is  divisible  into  a  shaft  and  two  extremities. 

The  superior  extremity  or  head  is  thick  and  large,  and  depressed  upon 
the  upper  part  by  a  concave  surface,  which  articulates  with  the  external 
tuberosity  of  the  tibia.  Externally  to  this  surface  is  a  thick  and  rough 
prominence,  for  the  attachment  of  the  external  lateral  ligament  of  the  knee- 
jomt,  terminated  behind  by  a  styloid  process,  for  the  insertion  of  the  ten- 
don of  the  biceps. 

The  lower  extremity  is  flattened  from  without  inwards,  and  prolonged 

*  Tluj  tibia  and  fibula  of  the  right  leg,  articulated  and  seen  from  the  front.  1.  The 
shaft  of  tne  tibia.  2.  The  inner  tuberosity.  3.  The  outer  tuberosity.  4.  The  spinous 
process  5.  The  tubercle.  6.  The  internal  or  subcutaneous  surface  of  the  shaft.  7.  The 
lower  extremity  of  the  tibia.  8.  The  internal  malleolus.  9.  The  shaft  of  the  fibula. 
10.  Its  upper  extremity.  11.  Its  lower  extremity,  the  external  malleolus.  The  sharp 
(order  oetween  1  and  6  is  the  crest  of  the  tibia. 


FIBULA. 


123 


Fig.  GO.1 


downwards  beyond  the  articular  surface  of  the  tibia,  forming  the  externat 
malleolus.  Its  external  side  presents  a  rough  and  triangular  surface,  which 
is  subcutaneous.  Upon  the  internal  surface  is  a  smooth  triangular  facet, 
to  articulate  writh  the  astragalus ;  and  a  rough  depression,  for  the  attach- 
ment of  the  interosseous  ligament.  The  anterior  border  is  thin  and  sharp ; 
and  the  posterior,  broad  and  grooved,  for  the  tendons  of  the  peronei 
muscles. 

To  place  the  bone  in  its  proper  position,  and  ascertain 
to  which  leg  it  belongs,  let  the  inferior  or  flattened  ex- 
tremity be  directed  downwards,  and  the  narrow  border 
of  the  malleolus  forwards ;  the  triangular  subcutaneous 
surface  will  then  point  to  the  side  corresponding  with  the  *" 
limb  of  which  the  bone  should  form  a  part. 

The  shaft  of  the  fibula  is  prismoid,  and  presents  three 
surfaces ;  external,  internal,  and  posterior ;  and  three 
borders.  The  external  surface  is  the  broadest  of  the 
three  ;  it  commences  upon  the  anterior  part  of  the  bone 
above,  and  curves  around  it  so  as  to  terminate  upon  its 
posterior  side  below.  This  surface  is  completely  occu- 
pied by  the  two  peronei  muscles.  The  internal  surface 
commences  on  the  side  of  the  superior  articular  surface, 
and  terminates  below,  by  narrowing  to  a  ridge,  \vhich  is 
continuous  with  the  anterior  border  of  the  malleolus.  It 
is  marked  along  its  middle  by  the  interosseous  ridge, 
which  is  lost  above  and  below  in  the  inner  border  of  the 
bone.  The  posterior  surface  is  twisted  like  the  external; 
it  commences  above  on  the  posterior  side  of  the  bone, 
and  terminates  below  on  its  internal  side ;  at  about  the 
middle  of  this  surface  is  the  nutritious  foramen,  which  is 
directed  downwards. 

The  internal  border  commences  superiorly  in  common 
with  the  interosseous  ridge,  and  bifurcates  inferiorly  into 
two  lines,  which  bound  the  triangular  subcutaneous  surface  of  the  external 
malleolus.  The  external  border  begins  at  the  base  of  the  styloid  process 
upon  the  head  of  the  fibula,  and  winds  around  the  bone,  following  the  di- 
rection of  the  corresponding  surface.  The  posterior  border  is  sharp  and 
prominent,  and  is  lost  inferiorly  in  the  interosseous  ridge. 

Development.  — By  three  centres ;  one  for  the  shaft,  and  one  for  each 
extremity.  Ossification  commences  in  the  shaft  soon  after  its  appearance 
in  the  tibia ;  at  birth  the  extremities  are  cartilaginous,  an  ossific  deposit 

*  The  tibia  and  fibula  of  the  right  leg  articulated  and  seen  from  behind.  1.  The  ar- 
ticular depression  for  the  external  condyle  of  the  femur.  2.  The  articular  depression, 
for  the  internal  condyLe ;  the  prominence  betsveen  the  two  numbers  is  the  spinous  pro- 
cess. 3.  The  fossa  and  groove  for  the  insertion  of  the  tendon  of  the  semirr">mbranosus 
muscle.  4.  The  popliteal  plane,  for  the  support  of  the  popliteus  muscie.  o.  The  po- 
pliteal line.  6.  The  nutritious  foramen.  7.  The  surface  of  the  shaft  upon  which  the 
flexor  longus  digitorum  muscle  rests.  8.  The  broad  groove  on  the  back  part  of  the  innei 
malleolus,  for  the  tendons  pf  the  flexor  longus  digitorum  and  tibialis  posticus.  9.  The 
groove  for  the  tendon  of  the  flexor  longus  pollicis.  10.  The  shaft  of  the  fibula.  The 
flexor  longus  pollicis  muscle  lies  upon  this  surface  of  the  bone  ;  its  superior  limit  being 
marked  by  the  oblique  line  immediately  above  the  number.  11.  The  styloid  process  on 
the  head  of  the  fibula  for  the  attachment  of  the  tendon  of  the  biceps  rruscle.  12.  The 
subcutaneous  surface  of  the  lower  part  of  the  shaft  of  the  fibula.  13.  The  external 
malleolus  formed  by  the  lower  extremity  of  the  fibula.  14.  The  groove  upon  the  pos 
terior  part  of  the  external  malleolus  for  the  tendons  of  the  peronei  muscles. 


124  TARSUS — ASTRAGALUS— CALCANEUS. 

taking  place  in  the  inferior  epiphysis  during  the  second  year,  and  in  tne 
superior  during  the  fourth  or  fifth.  The  inferior  epiphysis  is  the  first  to 
become  united  with  the  diaphysis,  but  the  bone  is  not  completed  until 
nearly  the  twenty-fifth  year. 

Articulations. — With  the  tibia  and  astragalus. 

Attachment  of  Muscles. — To  nine  ;  by  the  head,  to  the  tendon  of  the 
biceps  and  soleus;  by  the  shaft,  its  external  surface,  to  the  peroneus 
longus  and  brevis  ;  internal  surface,  to  the  extensor  longus  digitorum, 
extensor  proprius  pollicis,  peroneus  tertius,  and  tibialis  posticus ;  by  the 
posterior  surface,  to  the  popliteus  and  flexor  longus  pollicis. 

TARSUS. — The  bones  of  the  tarsus  are  seven  in  number  ;  viz.  the  astra- 
galus, calcaneus,  scaphoid,  internal  middle,  and  external  cuneiform  and 
cuboid. 

The  ASTRAGALUS  (os  tali)  may  be  recognised  by  its  rounded  head,  a 
broad  articular  facet  upon  its  convex  surface,  and  two  articular  facets, 
separated  by  a  deep  groove,  upon  its  concave  surface. 

The  bone  is  divisible  into  a  superior  and  inferior  surface,  an  external 
and  internal  border,  and  an  anterior  and  posterior  extremity.  The  supe- 
rior surface  is  convex,  and  presents  a  large  quadrilateral  and  smooth  facet 
somewhat  broader  in  front  than  behind,  to  articulate  with  the  tibia.  The 
inferior  surface  is  concave,  and  divided  by  a  deep  and  rough  groove  (sul- 
cus  tali),  which  lodges  a  strong  interoessous  ligament,  into  two  facets,  the 
posterior  large  and  quadrangular,  and  the  anterior  smaller  and  elliptic, 
which  articulate  with  the  os  calcis.  The  internal  border  is  flat  and  irre- 
gular, and  marked  by  a  pyriform  articular  surface,  for  the  inner  malleolus. 
The  external  presents  a  large  triangular  articular  facet,  for  the  external 
malleolus,  and  is  rough  and  concave  in  front.  The  anterior  extremity 
presents  a  rounded  head,  surrounded  by  a  constriction  somewhat  resem- 
bling a  neck ;  and  the  posterior  extremity  is  narrow,  and  marked  by  a 
deep  groove,  for  the  tendon  of  the  flexor  longus  pollicis. 

Hold  the  astragalus  with  the  broad  articular  surface  upwards,  and  the 
rounded  head  forwards ;  the  triangular  lateral  articular  surface  will  point 
to  the  side  to  which  the  bone  belongs. 

Articulations. — With  four  bones ;  tibia,  fibula,  calcaneus,  and  sca- 
phoid. 

The  CALCANEUS  (os  calcis)  may  be  known  by  its  large  size  and  oblong 
figure,  by  the  large  and  irregular  portion  which  forms  the  heel,  and  by  two 
articular  surfaces,  separated  by  a  broad  groove  upon  its  upper  side. 

The  calcaneus  is  divisible  into  four  surfaces,  superior,  interior,  external, 
and  internal ;  and  two  extremities,  anterior  and  posterior.  The  superior 
surface  is  convex  behind  and  irregularly  concave  in  front,  where  it  pre- 
sents two,  and  sometimes  three  articular  facets,  divided  by  a  broad  and 
shallow  groove  (sulcus  calcanei),  for  the  interosseous  ligament.  The  in- 
ferior surface  is  convex  and  rough,  and  bounded  posteriorly  by  the  two 
inferior  tuberosities,  of  wrhich  the  internal  is  broad  and  large,  and  the  ex- 
ternal smaller  and  prominent  The  external  surface  is  convex  and  sub- 
cutaneous, and  marked  towards  its  anterior  third  by  two  grooves,  often 
separated  by  a  tubercle,  for  the  tendons  of  the  peroneus  longus  and  brevis 
The  internal  surface  is  concave  and  grooved,  for  the  tendons  and  vessels 
which  pass  into  the  sole  of  the  foot.  At  the  anterior  extremity  of  "Jiis 


SCAPHOID  AND  CUNEIFORM  BONES. 


125 


surface  is  a  projecting  process  (sustentaculum  tali),  Fig.  6i  * 
which  supports  the  anterior  articulating  surface  of  the 
astragalus,  and  serves  as  a  pulley  to  the  tendon  of  the 
flexor  longus  digitorum.  Upon  the  anterior  extremity 
is  a  flat  articular  surface,  surmounted  by  a  rough  pro- 
jection, which  affords  one  of  the  guides  to  the  surgeon 
in  the  performance  of  Chopart's  operation.  The  pos- 
terior extremity  is  prominent  and  convex,  and  consti- 
tutes the  posterior  tuberosity ;  it  is  smooth  for  the 
upper  half  of  its  extent,  where  it  corresponds  with  a 
bursa;  and  rough  below,  for  the  insertion  of  the 
tendo  Achillis  ;  the  lower  part  of  this  surface  is  bound- 
ed by  the  two  inferior  tuberosities. 

Articulations.  —  With  two  bones ;  the  astragalus 
and  cuboid.  In  their  articulated  state  a  large  oblique 
canal  is  situated  between  the  astragalus  and  calcaneus, 
being  formed  by  the  apposition  of  the  two  grooves 
sulcus  tali  and  calcanei.  This  groove  is  called  the 
sinus  tarsi,  and  serves  to  lodge  a  strong  interosseous 
ligament  which  binds  the  two  bones  together. 

Attachment  of  Muscles. — To  nine ;  by  the  poste- 
rior tuberosity,  to  the  tendo  Achillis  and  plantaris  ;  by  the  inferior  tube- 
rosities and  under  surface,  to  the  abductor  pollicis,  abductor  minimi 
digiti,  flexor  brevis  digitorum,  flexor  accessorius,  and  to  the  plantar  fascia ; 
and  by  the  external  surface,  to  the  extensor  brevis  digitorum. 

The  SCAPHOID  bone  may  be  distinguished  by  its  boat-like  figure,  con- 
cave on  one  side,  and  convex  with  three  facets  upon  the  other.  It  pre- 
sents for  examination  an  anterior  and  posterior  surface,  a  superior  and 
inferior  border,  and  two  extremities,  one  broad,  the  other  pointed  and 
thick.  The  anterior  surface  is  convex,  and  divided  into  three  facets,  to 
articulate  with  the  three  cuneiform  bones ;  and  the  posterior  concave,  to 
articulate  with  the  rounded  head  of  the  astragalus.  The  superior  border 
is  convex  and  rough,  and  the  inferior  somewhat  concave  and  irregular. 
The  external  extremity  is  broad  and  rough,  and  the  internal  pointed  and 
prominent,  so  as  to  form  a  tuberosity.  The  external  extremity  sometimes 
presents  a  facet  of  articulation  with  the  cuboid. 

If  the  bone  be  held  so  that  the  convex  surface  with  three  facets  look 
forwards,  and  the  convex  border  upwards,  the  broad  extremity  will  point 
to  the  side  corresponding  with  the  foot  to  which  the  bone  belongs. 

Articulations. — With  four  bones;  astragalus  and  three  cuneiform  bones, 
sometimes  also  with  the  cuboid. 

Attachment  of  Muscles. — To  the  tendon  of  the  tibialis  posticus. 

The  INTERNAL  CUNEIFORM  may  be  known  by  its  irregular  wedge-shape, 
and  by  being  larger  than  the  two  other  bones  bearing  the  same  name.  It 

*  The  dorsal  surface  of  the  left  foot.  1.  The  astragalus ;  its  superior  quadrilateral 
articular  surface.  2.  The  anterior  extremity  of  the  astragalus,  which  articulates  with 
(4)  the  scaphoid  bone.  3.  The  os  calcis.  4.  The  scaphoid  bone.  5.  The  internal 
cuneiform  bone.  6.  The  middle  cuneiform  bone.  7.  The  external  cuneiform  bone. 
8.  The  cuboid  bone.  9.  The  metatarsal  bones  of  the  first  and  second  toes.  10.  The 
first  phalanx  of  the  great  toe.  11.  The  second  phalanx  of  the  great  toe.  12.  The  first 
phalanx  of  the  second  toe.  13.  Its  second  phalanx.  14.  Its  third  phalanx. 

n* 


126  CUNEIFORM  AND  CUBOID  BONES. 

presents  for  examination  a  convex  and  a  concave  surface,  a  long  and  a 
short  articular  border,  and  a  small  and  a  large  extremity. 

Place  the  bone  so  that  the  small  extremity  may  look  upwaids  and  the 
long  articular  border  forwards,  the  concave  surface  will  point  to  the  side 
corresponding  with  the  foot  to  which  it  belongs. 

The  convex  surface  is  internal  and  free,  and  assists  in  forming  the  inner 
border  of  the  foot ;  the  concave  is  external,  and  in  apposition  with  the 
middle  cuneiform  and  second  metatarsal  bone;  the  long  border  articulates 
with  the  metatarsal  bone  of  the  great  toe,  and  the  short  border  with  the 
scaphoid  bone.  The  small  extremity  (edge)  is  sharp,  and  the  larger  ex- 
tremity (base)  rounded  into  a  broad  tuberosity. 

Articulations.  —  With  four  bones;  scaphoid,  middle  cuneiform,  and 
first  two  metatarsal  bones. 

Attachment  of  Muscles. — To  the  tibialis  anticus,  and  posticus. 

The  MIDDLE  CUNEIFORM  is  the  smallest  of  the  three ;  it  is  wedge- 
shaped,  the  broad  extremity  being  placed  upwards,  and  the  sharp  end 
downwards  in  the  foot.  It  presents  for  examination  four  articular  sur- 
faces and  two  extremities.  The  anterior  and  posterior  surfaces  have 
nothing  worthy  of  remark.  One  of  the  lateral  surfaces  has  a  long  arti- 
cular facet,  extending  its  whole  length,  for  the  internal  cuneiform ;  the 
other  has  only  a  partial  articular  facet  for  the  external  cuneiform  bone. 

If  the  bone  be  held  so  that  the  square  extremity  look  upwards,  the 
broadest  side  of  the  square  being  towards  the  holder,  the  small  and  partial 
articular  surface  will  point  to  the  side  to  which  the  bone  belongs. 

Articulations.  —  With  four  bones ;  scaphoid,  internal  and  external 
cuneiform,  and  second  metatarsal  bone. 

Attachment  of  Muscles. — To  the  flexor  brevis  pollicis. 

The  EXTERNAL  CUNEIFORM  is  intermediate  in  size  between  the  two 
preceding,  and  placed,  like  the  middle,  with  the  broad  end  upwards  and 
the  sharp  extremity  downwards.  It  presents  for  examination  five  surfaces, 
and  a  superior  and  inferior  extremity.  The  upper  extremity  is  flat,  of  an 
oblong  square  form,  and  bevelled  posteriorly,  at  the  expense  of  the  outer 
surface,  into  a  sharp  edge. 

If  the  bone  be  held  so  that  the  square  extremity  look  upwards  and  the 
sharp  border  backwards,  the  bevelled  surface  will  point  to  the  side  corre- 
sponding with  the  foot  to  which  the  bone  belongs. 

Articulations.  —  With  six  bones;  scaphoid,  middle  cuneiform,  cuboid, 
and  second,  third,  and  fourth  metatarsal  bones. 

Attachment  of  Muscles. — To  the  flexor  brevis  pollicis. 

The  CUBOID  BONE  is  irregularly  cuboid  in  form,  and  marked  upon  its 
under  surface  by  a  deep  groove,  for  the  tendon  of  the  peroneus  longus 
muscle.  It  presents  for  examination  six  surfaces,  three  articular  and 
three  non-articular.  The  non-articular  surfaces  are  the  superior,  which  is 
slightly  convex,  and  assists  in  forming  the  dorsum  of  the  foot ;  the  inferior, 
marked  by  a  prominent  ridge,  the  tuberosity,  and  a  deep  groove  for  the 
tendon  of  the  peroneus  longus;  and  an  external,  the  smallest  of  the  whole, 
and  deeply  notched  by  the  commencement  of  the  peroneal  groove.  The 
articular  surfaces  are,  the  posterior,  which  is  of  large  size,  and  concavo- 
convex,  to  articulate  with  the  os  calcis ;  anterior,  of  smaller  size,  divided 


METATARSAL   BONES.  ^27 

* 

by  a  slight  ridge  into  two  facets,  for  the  fourth  and  fifth  metatarsal  bones ; 
and  internal,  a  small  oval  articular  facet,  upon  a  large  and  quadrangular 
surface,  for  the  external  cuneiform  bone. 

I*f  the  bone  be  held  so  that  the  plantar  surface,  with  the  peroneal  groove, 
look  downwards,  and  the  largest  articular  surface  backwards,  the  small 
non-articular  surface,  marked  by  the  deep  notch,  will  point  to  the  side 
corresponding  with  the  foot  to  which  the  bone  belongs. 

Articulations.  —  With  four  bones ;  calcaneus,  external  cuneiform,  and 
fourth  and  fifth  metatarsal  bones,  sometimes  also  with  the  scaphoid. 

Attachment  of  Muscles.  —  To  three ;  the  flexor  brevis  pollicis,  adductor 
pollicis,  and  flexor  brevis  minimi  digiti. 

Upon  a  consideration  of  the  articulations  of  the  tarsus  it  will  be  ob- 
served, that  each  bone  articulates  with  four  adjoining  bones,  with  the  ex- 
ception of  the  calcaneus,  which  articulates  with  two,  and  the  external 
cuneiform  with  six. 

Development. — By  a  single  centre  for  each  bone,  with  the  exception  of 
the  os  calcis,  which  has  an  epiphysis  for  its  posterior  tuberosity.  The 
centres  appear  in  the  following  order:  calcanean,  sixth  month;  astra- 
galan,  seventh  month ;  cuboid,  tenth  month ;  external  cuneiform,  during 
the  first  year ;  internal  cuneiform,  during  the  third  year ;  middle  cunei- 
form and  scaphoid,  during  the  fourth  year.  The  epiphysis  of  the  calca- 
neus appears  at  the  ninth  year,  and  is  united  with  the  diaphysis  at  about 
the  fifteenth. 

The  METATARSAL  BONES,  five  in  number,  are  long  bones,  and  divisible 
therefore  into  a  shaft  and  two  extremities.  The  shaft  is  prismoid,  and 
compressed  from  side  to  side ;  the  posterior  extremity,  or  base,  is  square- 
shaped,  to  articulate  with  the  tarsal  bones,  and  with  each  other ;  and  the 
anterior  extremity  presents  a  rounded  head,  circumscribed  by  a  neck,  to 
articulate  with  the  first  row  of  phalanges. 

Peculiar  Metatarsal  Bones. — The  first  is  shorter  and  larger  than  the 
rest,  and  forms  part  of  the  inner  border  of  the  foot ;  its  posterior  extremity 
presents  only  one  lateral  articular  surface,  and  an  oval  rough  prominence 
beneath,  for  the  insertion  of  the  tendon  of  the  peroneus  longus.  The 
anterior  extremity  has,  upon  its  plantar  surface,  two  grooved  facets,  for 
sesamoid  bones. 

The  second  is  the  longest  and  largest  of  the  remaining  metatarsal  bones ; 
it  presents  at  its  base  three  articular  facets,  for  the  three  cuneiform  bones ; 
a  large  oval  facet,  but  often  no  articular  surface,  on  its  inner  side,  to  arti- 
culate with  the  metatarsal  bone  of  the  great  toe,  and  two  externally  for 
the  third  metatarsal  bone. 

The  third  may  be  known  by  two  facets  upon  the  outer  side  of  its  base, 
corresponding  with  the  second,  and  may  be  distinguished  by  its  smaller 
size. 

The  fourth  may  be  distinguished  by  its  smaller  size,  and  by  having  a 
single  articular  surface  on  each  side  of  the  base. 

The  fifth  is  recognised  by  its  broad  base,  and  by  its  large  tuberosity  in 
place  of  an  articular  surface  upon  its  outer  side. 

Development. — Each  bone  by  two  centres ;  one  for  the  body  and  one 
for  the  digital  extremity  in  the  four  outer  metatarsal  bones ;  and  one  for 
the  body,  the  other  for  the  base  in  the  metatarsal  bone  of  the  great  toe 
Ossific  deposition  appears  in  these  bones  at  the  same  time  with  the  verte- 


PHALANGES. 

bra? ;  the  epiphyses,  commencing  with  the  great  to« 
and  proceeding  to  the  fifth,  appear  towards  the  close 
of  the  second  year,  consolidation  being  effected  at 
eighteen. 

Articulations. — With  the  tarsal  bones  by  one  ex- 
tremity, and  with  the  first  row  of  phalanges  by  the 
other.  The  number  of  tarsal  bones  with  which  each 
metatarsal  articulates  from  within  outwards,  is  the 
same  as  between  the  metacarpus  and  carpus,  one  for 
the  first,  three  for  the  second,  one  for  the  third,  two 
for  the  fourth,  and  one  for  the  fifth,  forming  the  cipher 
13121. 

Attachment  of  Muscles. — To  fourteen;  to  the  first, 
the  peroneus  longus  and  first  dorsal  interosseous 
muscle ;  to  the  second,  two  dorsal  interossei  and 
transversus  pedis ;  to  the  third,  two  dorsal  and  one 
plantar  interosseous,  adductor  pollicis  and  transversus 
pedis ;  to  the  fourth,  two  dorsal  and  one  plantar 
interosseous,  adductor  pollicis  and  transversus  pedis  : 
to  the  fifth,  one  dorsal  and  one  plantar  interosseous, 
peroneus  brevis,  peroneus  tertius,  abductor  minimi 
digiti,  flexor  brevis  minimi  digiti,  and  transversus  pedis. 

PHALANGES. — There  are  two  phalanges  in  the  great  toe,  and  three  in 
the  other  toes,  as  in  the  hand.  They  are  long  bones,  divisible  into  a 
central  portion  and  extremities. 

The  phalanges  of  the  first  row  are  convex  above,  concave  upon  the 
under  surface,  and  compressed  from  side  to  side.  The  posterior  extre- 
mity has  a  single  concave  articular  surface,  for  the  head  of  the  metatarsal 
bone ;  and  the  anterior  extremity,  a  pulley-like  surface  for  the  second 
phalanx. 

The  second  phalanges  are  short  and  diminutive,  but  somewhat  broader 
than  those  of  the  first  row. 

The  third,  or  ungual  phalanges,  including  the  second  phalanx  of  the 
great  toe,  are  flattened  from  above  downwards,  spread  out  laterally  at  the 
base,  to  articulate  with  the  second  row,  and  at  the  opposite  extremity,  to 
support  the  nail  and  the  rounded  extremity  of  the  toe. 

Development. — By  two  centres ;  one  for  the  body  and  one  for  the  meta- 
carpal  extremity.  Ossification  commences  in  these  bones  after  that  in  the 
metatarsus,  appearing  first  in  the  last  phalanges,  then  in  the  first,  and  last 
of  all  in  the  middle  row.  The  bones  are  completed  at  eighteen. 

•Articulations. — The  first  row  with  the  metatarsal  bones  and  second 
phalanges ;  the  second,  of  the  great  toe  with  the  first  phalanx,  and  of  the 

*  The  sole  of  the  left  foot.  1.  The  inner  tuberosity  of  the  os  calcis.  2.  The  outer 
tnberosity.  3.  The  groove  for  the  tendon  of  the  flexor  longus  digitorum  ;  this  figure 
indicates  also  the  sustentaculum  tali.  4.  The  rounded  head  of  the  astragalus.  5.  The 
scaphoid  bone.  6.  Its  tuberosity,  7.  The  internal  cuneiform  bone ;  its  broad  extremity, 
8.  The  middle  cuneiform  bone.  9.  The  external  cuneiform  bone.  10,  11.  The  cuboid 
bone.  11.  Refers  to  the  groove  for  the  tendon  of  the  peroneus  longus  :  the  prominence 
between  this  groove  and  figure  10  is  the  tuberosity.  12,  12.  The  metatarsal  bones. 
13,  13.  The  first  phalanges.  14,  14.  The  second  phalanges  of  the  four  lesser  toes. 
15,  15.  The  third,  or  ungual  phalanges  of  the  four  lesser  toes.  16.  The  last  phalanx 
cT  the  great  toe 


SESAMOID   BONES.  129 

other  toes  with  the  first  and  third  phalanges ;  and  the  third,  with  the  se- 
cond row. 

Attachment  of  Muscles. — To  twenty-three;  to  the  first  phalanges;  great 
toe,  the  innermost  tendon  of  the  extensor  brevis  digitorum,  abductor  pol- 
licis,  adductor  pollicis,  flexor  brevis  pollicis,  and  transversus  pedis  ;  second 
toe,  first  dorsal  and  first  palmar  interosseous  and  lumbricalis ;  third  toe, 
second  dorsal  and  second  palmar  interosseous  and  lumbricalis ;  fourth  toe, 
third  dorsal  and  third  palmar  interosseous  and  lumbricalis ;  fifth  toe, 
fourth  dorsal  interosseous,  abductor  minimi  digiti,  flexor  brevis  minimi 
digiti  and  lumbricalis.  Second  phalanges  ;  great  toe,  extensor  longus  pol- 
licis, and  flexor  longus  pollicisv;  other  toes,  one  slip  of  the  common  tendon 
of  the  extensor  longus  and  extensor  brevis  digitorum,  and  flexor  brevis 
digitorum.  Third  phalanges;  two  slips  of  the  common  tendon  of  the 
extensor  longus  and  extensor  brevis  digitorum,  and  the  flexor  longus  digi- 
torum. 

SESAMOID  BOXES. — These  are  small  osseous  masses,  developed  in  those 
tendons  which  exert  a  certain  degree  of  force  upon  the  surface  over  which 
they  glide,  or  where,  by  continued  pressure  and  friction,  the  tendon  would 
become  a  source  of  irritation  to  neighbouring  parts,  as  to  joints.  The 
best  example  of  a  sesamoid  bone  is  the  patella,  developed  in  the  common 
tendon  of  the  quadriceps  extensor,  and  resting  upon  the  front  of  the  knee- 
joint.  Besides  the  patella,  there  are  four  pairs  of  sesamoid  bones  included 
in  the  number  of  pieces  which  compose  the  skeleton,  two  upon  the  meta- 
carpo-phalangeal  articulation  of  each  thumb,  and  existing  in  the  tendons 
of  insertion  of  the  flexor  brevis  pollicis,  and  two  upon  the  corresponding 
joint  in  the  foot,  in  the  tendons  of  the  muscles  inserted  into  the  base  of 
the  first  phalanx.  In  addition  to  these,  there  is  often  a  sesamoid  bone 
upon  the  metacarpo-phalangeal  joint  of  the  little  finger ;  and  upon  the 
corresponding  joint  in  the  foot,  in  the  tendons  inserted  into  the  base  of 
the  first  phalanx ;  there  is  one  also  in  the  tendon  of  the  peroneus  longus 
muscle,  where  it  glides  through  the  groove  in  the  cuboid  bone  ;  sometimes 
in  the  tendons,  as  they  wind  around  the  inner  and  outer  malleolus;  in  the 
psoas  and  iliacus,  where  they  glide  over  the  body  of  the  os  pubis ;  and  in 
the  external  head  of  the  gastrocnemius. 

The  bones  of  the  tympanum,  as  they  belong  to  the  apparatus  of  hearing, 
will  be  described  with  the  anatomy  of  the  ear. 


CHAPTER  III. 

ON  THE  LIGAMENTS. 

THE  bones  are  variously  connected  with  each  other  in  the  construction 
of  the  skeleton,  and  the  connexion  between  any  two  bones  constitutes  a 
joint  or  articulation.  If  the  joint  be  immovable,  the  surfaces  of  the  bonos 
are  applied  in  direct  contact ;  but  if  motion  be  intended,  the  opposing 
surfaces  are  expanded,  and  coated  by  an  elastic  substance,  named  carti- 
lage ;  a  fluiu  secreted  by  a  membrane  closed  on  all  sides  lubricates  their 

i 


130  ARTICULATIONS. 

surface,  and  they  are  firmly  held  together  by  means  of  short  bands  of 
glistening  fibres,  which  are  called  ligaments  (ligare,  to  bind).  The  study 
of  the  ligaments  is  named  syndesmology  (<Jw  together,  Sstpvs  bond),  which, 
with  the  anatomy  of  the  articulations,  forms  the  subject  of  the  present 
chapter. 

The  forms  of  articulation  met  with  in  the  human  frame  may  be  consi- 
dered under  three  classes :  Synarthrosis,  Amphi-arthrosis,  and  IJiarthrosis. 

SYNARTHROSIS  (  tfuv,  a^guaig  articulation)  is  expressive  of  the  fixed  form 
of  joint  in  which  the  bones  are  immovably  connected  with  each  other. 
The  kinds  of  synarthrosis  are  four  in  number.  1.  Sutura.  2.  Harmonia. 
3.  Schindylesis.  4.  Gomphosis.  The  characters  of  the  three  first  have 
been  sufficiently  explained  in  the  preceding  chapter,  p.  83.  It  is  here 
only  necessary  to  state  that,  in  the  construction  of  sutures,  the  substance 
of  the  bones  is  not  in  immediate  contact,  but  is  separated  by  a  layer  of 
membrane  which  is  continuous  externally  with  the  pericranium  and  inter- 
nally with  the  dura  mater.  It  is  the  latter  connexion  which  gives  rise  to 
the  great  difficulty  sometimes  experienced  in  tearing  the  calvarium  from 
the  dura  mater.  Cruveilhier  describes  this  interposed  membrane  as  the 
sutural  cartilage ;  I  never  saw  any  structure  in  the  sutures  which  could 
be  regarded  as  cartilage,  and  the  history  of  the  formation  of  the  cranial 
bones  would  seem  to  point  to  a  different  explanation.  The  fourth,  Gom- 
phosis (yo'fKpos,  a  nail),  is  expressive  of  the  insertion  of  one  bone  into 
another,  in  the  same  manner  that  a  nail  is  fixed  into  a  board ;  this  is  il- 
lustrated in  the  articulation  of  the  teeth  with  the  alveoli  of  the  maxillary 
bones. 

AMPHI-ARTHROSIS  (d/jt,cp<  both,  HtfpiXtts)  is  a  joint  intermediate  in  aptitude 
for  motion  between  the  immovable  synarthrosis  and  the  movable  diarthro- 
sis.  It  is  constituted  by  the  approximation  of  surfaces  partly  coated  with 
cartilage  lined  by  synovial  membrane,  and  partly  connected  by  interosse- 
ous  ligaments,  or  by  the  intervention  of  an  elastic  fibro-cartilage  which 
adheres  to  the  ends  of  both  bones.  Examples  of  this  articulation  are  seen 
in  the  union  between  the  bodies  of  the  vertebrae,  of  the  sacrum  with  the 
coccyx,  of  the  pieces  of  the  sternum,  the  sacro-iliac  and  pubic  symphyses 
(ffOv,  (piJsiv,  to  grow  together),  and  according  to  some,  of  the  necks  of  the 
ribs  with  the  transverse  processes. 

DIARTHROSIS  (810.  through,  a^wrfig)  is  a  movable  articulation,  which 
constitutes  by  far  the  greater  number  of  the  joints  of  the  body.  The  de- 
gree of  motion  in  this  class  has  given  rise  to  a  subdivision  into  three  genera, 
Arthrodia,  Ginglymus,  and  Enarthrosis. 

Jlrthrodia  is  the  movable  joint  in  which  the  extent  of  motion  is  slight 
and  limited,  as  in  the  articulation  of  the  clavicle,  of  the  ribs,  articular  pro- 
cesses of  the  vertebrae,  axis  with  the  atlas,  radius  with  the  ulna,  fibula 
with  the  tibia,  carpal  and  metacarpal,  tarsal  and  metatarsal  bones. 

Ginglymus  (7177X1^0?,  a  hinge),  or  hinge-joint,  is  the  movement  of 
bones  upon  each  other  in  two  directions  only,  viz.  forwards  arid  back- 
wards ;  but  the  degree  of  motion  may  be  very  considerable.  The  instances 
of  this  form  of  joint  are  numerous ;  they  comprehend  the  elbow,  wrist, 
metacarpo-phalangeal  and  phalangeal  joints  in  the  upper  extremity ;  and 
the  knee,  ankle,  metatarso-phalangeal  and  phalangeal  joints  in  the  lower 
extremity.  The  lower  jaw  may  also  be  admitted  into  this  category,  as 
partaking  more  of  the  character  of  the  hinge-joint  than  the  less  movable 
arthro'di? 


MOVEMENTS    OF   JOINTS.  13] 

The  form  of  the  ginglymoid  joint  is  somewhat  quadrilateral,  and  each 
of  its  four  sides  is  provided  with  a  ligament,  which  is  named  from  its  posi- 
tion, anterior,  posterior,  internal,  or  external  lateral.  The  lateral  liga- 
•nents  are  thick  and  strong,  and  are  the  chief  bond  of  union  between  the 
bones.  The  anterior  and  posterior  are  thin  and  loose,  in  order  to  permit 
the  required  extent  of  movement. 

Enarthrosis  (sv  in,  &gt$ugts)  is  the  most  extensive  in  its  range  of  motion 
of  all  the  movable  joints.  From  the  manner  of  connexion  and  form  of 
the  bones  in  this  articulation,  it  is  called  the  ball-and-socket-joint.  There 
are  two  instances  in  the  body,  viz.  the  hip  and  the  shoulder. 

I  have  been  in  the  habit  of  adding  to  the  preceding  the  carpo-metacar- 
pal  articulation  of  the  thumb,  although  not  strictly  a  ball-and-socket-joint, 
from  the  great  extent  of  motion  which  it  enjoys,  and  from  the  nature  of  the 
ligament  connecting  the  bones.  As  far  as  the  articular  surfaces  are  con- 
cerned, it  is  rather  a  double  than  a  single  ball-and-socket,  and  the  whole 
of  these  considerations  remove  it  from  the  simple  arthrodial  and  ginglymoid 
groups. 

The  ball-and-socket  joint  has  a  circular  form ;  and  in  place  of  the  four 
distinct  ligaments  of  the  ginglymus,  is  enclosed  in  a  bag  of  ligameritous 
membrane,  called  a  capsular  ligament. 

The  kinds  of  articulation  may  probably  be  conveyed  in  a  more  satis- 
factory manner  in  the  tabular  form,  thus : 

f  Sutura    -     -  -  -  bones  of  the  skull. 

Q        ,1  1  Harmonia     -  -  -  superior  maxillary  bones. 

51S<      1  Schindylesis  -  -  vomer  with  rostrum. 

[  Gomphosis  -  -  -  teeth  with  alveoli. 

Amphi-arthrosis    -     Bodies  of  the  vertebrae     -     Symphyses. 

C  Arthrodia     -  -  -  carpal  and  tarsal  bones. 

Diarthrosis.        <  Ginglymus  -  -  -  elbow,  wrist,  knee,  ankle. 

( Enarthrosis  -  -  -  hip,  shoulder. 

The  motions  permitted  in  joints  may  be  referred  to  four  heads,  viz.  1. 
Gliding.  2.  Angular  movement.  3.  Circumduction.  4.  Rotation. 

1.  Gliding  is  the  simple  movement  of  one  articular  surface  upon  an- 
other, and  exists  to  a  greater  or  less  extent  in  all  the  joints.     In  the  least 
movable  joints,  as  in  the  carpus  and  tarsus,  this  is  the  only  motion  which  is 
permitted. 

2.  Angular  movement  may  be  performed  in  four  different  directions, 
either  forwards  and  backwards,  as  in  flexion  and  extension ;  or  inwards 
and  outwards,  constituting  adduction  and  abduction.    Flexion  and  exten- 
sion are  .illustrated  in  the  ginglymoid  joint,  and  exist  in  a  large  proportion 
of  the  joints  of  the  body.  Adduction  and  abduction  conjoined  with  flexion 
and  extension,  are  met  with  complete,  only  in  the  most  movable  joints, 
as  in  the  shoulder,  the  hip,  and  the  thumb.     In  the  wrist  and  in  the  ankle 
adduction  and  abduction  are  only  partial. 

3.  Circumduction  is  most  strikingly  exhibited  in  the  shoulder  and  hip- 
joints  ;  it  consists  in  the  slight  degree  of  motion  which  takes  place  in  the 
head  of  a  bone  against  its  articular  cavity,  while  the  extremity  of  the  limb 
is  made  to  describe  a  large  circle  upon  a  plane  surface.     It  is  also  seen, 
but  in  a  less  degree,  in  the  carpo-metacarpal  articulation  of  the  thumb, 
metacarpo-phalangeal  articulations  of  the  fingers  and  toes,  and  in  the 
elbow  when  that  joint  is  flexed  and  the  end  of  the  humerus  fixed. 


132  STRUCTURE    OF    CARTILAGE. 

4.  Rotation  is  the  movement  of  a  bone  upon  its  own  axis,  and  is  illi.s- 
trated  in  the  hip  and  shoulder,  or  better  in  the  rotation  of  the  cup  of  the 
radius  against  the  eminentia  capitata  of  the  humerus.  Rotation  is  also 
observed  in  the  movements  of  the  atlas  upon  the  axis,  in  which  the  odon- 
toid process  serves  as  a  pivot  around  which  the  atlas  turns. 

The  structures  entering  into  the  composition  of  a  joint  are  Done,  carti 
iage,  fibrous  tissue,  adipose  tissue,  and  synovial  membrane.  Cartilag 
forms  a  thin  coating  to  the  articular  extremities  of  bones,  sometimes  pre 
senting  a  smooth  surface  which  moves  on  a  corresponding  smooth  surface 
of  the  articulating  bone  ;  sometimes  forming  a  plate  smooth  on  both  sur 
faces  and  interposed  between  the  cartilaginous  ends  of  two  bones,  inter- 
articular  ;  and  sometimes  acting  as  the  connecting  medium  between  bones 
without  any  free  surface,  interosseous.  Fibrous  tissue  enters  into  the  con- 
struction of  joints  under  the  form  of  ligament,  in  one  situation  constituting 
bands  of  various  breadth  and  thickness,  in  another  a  layer  which  extends 
completely  around  the  joint,  and  is  then  called  a  capsular  ligament.  All 
the  ligaments  of  joints  are  composed  of  that  variety  of  fibrous  tissue  term- 
ed white  fibrous  tissue,  but  in  some  situations  ligaments  are  found  which 
consist  of  yellow  fibrous  tissue,  for  example,  the  ligamenta  subflava  of  the 
arches  of  the  vertebral  column.  Adipose  tissue  exists  in  variable  quantity 
in  relation  with  joints,  where  it  performs,  among  other  offices,  that  of  a 
valve  or  spring,  which  occupies  any  vacant  space  that  may  be  formed 
during  the  movements  of  the  joint,  and  effectually  prevents  the  occurrence 
of  a  vacuum  in  those  cavities.  This  purpose  of  adipose  tissue  is  exempli- 
fied in  the  cushion  of  fat  at  the  bottom  of  the  acetabulum,  and  in  the 
similar  cushion  behind  the  ligamentum  patellaB.  Synovial  membrane 
constitutes  the  beautiful  smooth  and  polished  lining  of  a  joint,  and  con- 
tains the  fluid  termed  synovia,  by  means  of  which  the  adapted  surfaces 
are  enabled  to  move  upon  each  other  with  the  perfect  ease  and  freedom 
which  are  known  to  exist. 

CARTILAGE. — In  the  structure  of  joints,  cartilage  serves  the  double  pur- 
pose of  a  connecting  and  separating  medium.  In  the  former  capacity 
possessing  great  strength,  and  in  the  latter  smoothness  and  elasticity.  In 

Fig.  03.*  Fig.  64.f 


3r  *    y 

/v// 

P    y  99 

A  portion  of  articular  cartilage  from  the  head  of  the  fibula,  showing  the  appearance 
nml  arntmri'ment  of  the  cells  near  to  the  bone.  The  section  is  made  vertically  to  the 
«urf;>ce,  and  magnified  155  diameters.  The  irregular  line  to  the  right  is  the  bo»rdary 
at'  the  bone 

*  A  \lc\4  of  the   same   section,  at   about  midway  between  the  bone  and  the  free  sur 
lace 


STRUCTURE    OF    CARTILAGE. 


133 


Fig.  65.* 


reference  to  its  intimate  structure  it  admits  of  classification  into  three 
kinds, — true  cartilage,  reticular  cartilage,  and  fibrous  cartilage. 

True  Cartilage  is  composed  of  a  semi-transparent  homo- 
geneous substance  (hyaline  or  vitreous  substance)  contain- 
ing a  number  of  minute  cells  (cartilage  corpuscles)  dispersed 
at  short  intervals  through  its  structure.  The  cells  are  oval, 
oblong,  or  polyhedral  in  shape,  and  more  or  less  flattened ; 
their  membranous  envelope  is  blended  with  the  intercellular 
substance,  and  they  contain  in  their  interior  secondary  cells, 
nuclei,  nucleoli,  oil-globules,  and  more  or  less  of  granular 
matter.  Cartilage  cells  have  an  average  measurement  of 
TB'O u  °f  an  i'icn  m  their  long  diameter ;  they  are  sometimes 
isolated,  sometimes  grouped  in  pairs,  and  sometimes  dis- 
posed in  a  linear  group  of  three  or  four.  They  are  larger 
near  the  bone  than  at  the  surface,  and  in  the  latter  situation 
are  long  and  slender  in  form,  and  arranged  in  rows  having  their  long  axis 
parallel  with  the  plane  of  the  surface.  True  cartilage  is  pearl-white  or 
bluish  and  opaline  in  colour,  and  its  intercellular  substance  is  semitrans- 
parent  and  structureless.  These  characters,  however,  are  changed  when 
it  exhibits  a  .tendency  to  ossify.  In  the  latter  case  the  intercellular  sub- 
stance becomes  fibrous  and  more  or  less  opaque,  its  colour  is  yellowish, 
and  the  cells  are  found  to  contain  a  greater  number  of  oil-globules  than 
in  its  natural  state. 

The  true  cartilages  are,  the  articular,  costal,  ensiform,  thyroid,  cricoid, 
arytenoid,  tracheal  and  bronchial,  nasal,  meatus  auris,  the  pulley  of  the 
trochlearis  muscle,  and  temporary  cartilage  or  the  cartilage  of  bone  pre- 
viously to  ossification.! 

Reticular  cartilage  is  composed  of  cells  (j^  of  an  inch  in  diameter), 
separated  from  each  other  by  an  opaque,  subfibrous,  intercellular  network, 
the  breadth  of  the  cells  being  considerably  greater  than  that  of  the  inter- 
cellular structure.  The  cells  are  parent  cells,  containing  others  of  second- 
ary formation,  together  with  nuclei,  nucleoli,  granular  matter,  and  oil- 
globules  in  greater  number  than  those  of  true  cartilage.  The  fibres  are 
short,  imperfect,  loose  in  texture,  and  yellowish.  The  instances  of  reti- 
cular cartilage  are,  the  pinna,  epiglottis,  and  Eustachian  tube. 


Fig.  66.* 


Fig.  67.§ 


*  A  portion  of  articular  cartilage  near  the  synovial  surface  of  an  articulation;  the  hue 
to  tlie  left  is  that  oftiie  synovial  boundary. 

t  Page  47. 

+  A  portion  of  reticular  cartilage.  The  section  is  taken  from  the  pinna,  and  ma;;n/ 
fied  155  diameters. 

4  A  portion  of  fibrous  cartilage.  The  section  is  token  from  the  symphysis  pubis,  .»:id 
magnified  1  55  diameters. 

12 


134 


WHITE    FIBROUS    TISSUE. 


Fibrous  cartilage  is  composed  of  a  network  of  white  glistening  fibres, 
collected  into  fasciculi  of  various  size,  and  containing  in  its  meshes  cells 
and  a  subfibrous  tissue  resembling  that  of  reticular  cartilage.  The  fibres 
of  fibrous  cartilages  are  identical  with  those  of  fibrous  tissue,  the  cells  are 
large  (about  T515(jth  of  an  inch)  as  in  reticular  cartilage,  and  the  areoke 
are  variable  in  dimensions.  It  is  this  latter  character  that  constitutes  the 
difference  between  different  fibrous  cartilages,  some  being  composed  al- 
most entirely  of  fibres  with  few  and  small  interstices,  as  the  interarticula 
cartilages,  while  others  exhibit  large  spaces  filled  with  an  imperfect  fibrou 
tissue  and  cells,  as  the  intervertebral  substance. 

The  fibrous  cartilages  admit  of  arrangement  into  four  groups,  namely, 
interarticular,  stratiform,  interosseous,  and  free.  The  instances  of  inter- 
articular  fibrous  cartilages  (menisci)  are  those  of  the  lower  jaw,  sternal 
and  acromial  end  of  the  clavicle,  wrist,  carpus,  knee,  to  which  may  be 
added  the  fibrous  cartilages  of  circumference,  glenoid  and  cotyloid.  The 
stratiform,  fibrous  cartilages  are  such  as  form  a  thin  coating  to  the  grooves 
on  bone  through  which  tendons  play.  The  interosseous  fibrous  cartilages 
are  the  intervertebral  substance  and  symphysis  pub  is.  The  free  fibrous 
cartilages  are  the  tarsal  cartilages  of  the  eyelids. 

The  development  of  cartilage  is  the  same  with  that  of  cartilage  of  bone 
(page  46),  the  different  forms  of  cartilage  resulting  from  subsequent  changes 
in  the  intercellular  substance  and  cells.  Thus,  for  example,  in  articular 
cartilage  the  cells  undergo  the  lowest  degree  of  development,  are  very 
disproportionate  to  the  intercellular  substance,  and  the  latter  remains  per 
manently  structureless.  In  reticular  cartilage  the  cells  possess  a  more 
active  growth,  and  surpass  in  bulk  the  intercellular  substance,  while  the 
latter  is  composed  also  of  cells,  which  assume  a  fibrous  disposition.  In 
fibrous  cartilage  development  is  most  energetic  in  the  intercellular  sub- 
stance ;  this  is  converted  into  fasciculi  of  fibrous  tissue,  while  the  inter- 
spaces are  filled  with  cells  and  imperfect  fibrous  tissue  in  every  stage  of 
development. 

FIBROUS  TISSUE  is  one  of  the  most  generally  dis- 
tributed of  all  the  animal  tissues ;  it  is  composed 
of  fibres  of  extreme  minuteness,  and  presents  itself 
under  three  elementary  forms ;  namely,  white  fibrous 
tissue,  yellow  fibrous  tissue,  and  red  fibrous  tissue. 
In  white  fibrous  tissue  the  fibres  are  cylindrical, 
exceedingly  minute,  (about  75^5  of  an  inch  in  di- 
ameter), transparent  and  undulating ;  they  are  col- 
lected into  small  fasciculi  (from  30^3  to  775303  °f 
an  inch)  and  these  latter  form  larger  fasciculi,  which 
according  to  their  arrangement  give  rise  to  the  pro- 
duction of  thin  lamina?,  membranes,  ligainentons 
bands,  and  tendinous  cords.  The  connecting  me- 
dium of  the  fibres  in  the  formation  of  the  primitive 
fasciculi  is  a  transparent  structureless  interfibrous 
substance  or  blastema,  to  which  in  most  situations 
are  added  numerous  minute  dark  filaments  derived 
from  nuclei  and  thence  termed  nuclear  filaments. 

*  White  fibrous  tissu»: — 2.  Straight  appearance  of  the  tissue  when  stretched.  1,  3, 
<.  5.  Various  wavy  appearances  which  the  tissue  exhibits  when  not  stretched. — Magni- 
/i«d  32u  diameters. 


Fig.  68.* 


YELLOW    FIBROUS    TISSUE. 


135 


The  nuclear  filaments  are  sometimes  wound  spirally  around  the  fasciculi 
or  interlace  with  their  separate  fibres,  at  other  times  they  are  variously 
twisted  and  run  parallel  with  the  fasciculi.  The  fasciculi  are  connected 
and  held  together  in  the  formation  of  membranes  and  cords  by  loose  fibres 
which  are  interwoven  between  them,  or  by  mutual  interlacement. 

Examples  of  white  librous  tissue  are  met  with  in  three  principal  forms, 
namely,  membrane,  ligament,  and  tendon. 

The  membranous  form  of  white  fibrous  tissue  is  seen  in  the  common 
connecting  medium  of  the  body,  namely,  fibre-cellular  or  areolar  tissue, 
in  which  the  membrane  is  extremely  thin  and  disposed  in  laminae,  bands, 
or  threads,  leaving  interstices  of  various  size  between  them.  It  is  seen 
also  in  the  condensed  covering  of  various  organs,  as  the  periosteum,  peri- 
chondrium,  capsulae  propriae  of  glands,  membranes  of  the  brain,  sclerotic 
coat  of  the  eyeball,  pericardium,  fascise ;  sheaths  of  muscles,  tendons, 
vessels,  nerves,  and  ducts ;  sheaths  of  the  erectile  organs,  and  the  corium 
of  the  dermic  and  mucous  membrane. 

Ligament  is  the  name  given  to  those  bands  of  various  breadth  and  thick- 
ness which  retain  the  articular  ends  of  bones  in  contact  in  the  construction 
of  joints.  They  are  glistening  and  inelastic,  and  composed  of  fasciculi 
of  fibrous  tissue  ranged  in  a  parallel  direction  side  by  side,  or  in  some 
situations  interwoven  with  each  other.  The  fasciculi  are  held  together 
by  separate  fibres,  or  by  areolar  tissue. 

Tendon  is  the  collection  of  parallel  fasciculi  of  fibrous  tissue,  by  means 
of  which  muscles  are  attached  to  bones.  They  are  constructed  on  the 
same  principle  writh  ligaments,  are  usually  rounded  in  their  figure,  but  in 
some  instances  are  spread  out  so  as  to  assume  a  membranous  form.  In 
the  latter  state  they  are  called  aponeuroses. 

Yellow  fibrous  tissue  is  known  also  by  the  appellation 
elastic  tissue,  from  one  of  its  more  prominent  physical  pro- 
perties, a  property  which  permits  of  its  fibres  being  drawn 
out  to  double  their  length,  and  again  returning  to  their 
original  dimensions.  The  fibres  of  elastic  tissue  are  trans- 
parent, brittle,  flat  or  polyhedral  in  shape,  colourless  when 
single,  but  yellowish  in  an  aggregated  form,  and  considera- 
bly thicker  (s^Vo  °f  an  mch  in  diameter)  than  the  fibres 
of  white  fibrous  tissue.  In  the  construction  of  their  pecu- 
liar tissue  they  communicate  with  each  other  by  means  of 
short  oblique  fibres,  which  unite  with  adjoining  fibres  at 
acute  or  obtuse  angles,  without  any  enlargement  of  the 
fibre  with  which  they  are  joined.  This  circumstance  has 
given  rise  to  the  idea  of  these  fibres  giving  off  branches, 
an  expression  derived  from  the  division  of  blood-vessels, 
and  another  term  borrowed  from  the  same  source  has  been 
applied  to  their  communication  with  each  other,  namely, 
inosculation  ;  but  both  these  expressions  in  their  literal  meaning  are  incor- 
rect. When  yellow  fibrous  tissue  is  cut  or  torn,  the  fibres  in  consequence 
of  their  elasticity  become  clubbed  and  curved  at  the  extremity,  a  striking 
character  of  this  tissue. 

*  Yellovr  fibrous  tissue,  shewing  the  curly  and  branched  disposition  of  its  fibriHa, 
their  definite  outline,  and  abrupt  mode  of  fracture.  At  1,  the  structure  is  not  disturbed. 
as  in  the  rest  of  the  specimen.  Magnified  320  diameters. 


136  ADIPOSE    TISSUE. 

The  instances  of  yellow  fibrous  tissue  are :  the  ligamenta  subflava  of 
the  arches  of  the  vertebra,  cordae  vocales,  thyro-epiglottic  ligament,  crico 
thyroidean  membrane,  the  membranous  layers  connecting  the  cartilaginous 
rings  of  the  trachea  and  bronchial  tubes,  the  capsula  propria  of  the  spleen 
and  the  middle  coat  of  arteries.  It  is  also  met  with  around  some  parts  of 
the  alimentary  canal,  as  the  cesophagus,  cardia,  and  anus,  around  the  male 
and  female  urethra,  in  the  fascia  lata,  and  in  the  corium  of  the  skin. 

Red  fibrous  tissue  is  also  termed  contractile  tissue,  from  a  peculiar  pro- 
perty which  it  possesses,  and  which  places  it  physiologically  in  an  inter- 
mediate position  between  white  fibrous  tissue  and  muscular  fibre.  Its 
fibres  are  cylindrical,  transparent,  reddish  in  hue,  and  collected  into  fasci- 
culi. It  is  met  with  in  the  corium  of  the  skin,  in  the  dartos,  around  the 
nipple,  in  the  excretory  ducts  of  glands,  in  the  coats  of  blood-vessels, 
particularly  veins,  in  the  iris,  in  the  intervascular  spaces  of  the  erectile 
tissue  of  the  penis  and  clitoris,  around  the  urethra,  and  around  the  vagina. 
ADIPOSE  TISSUE  is  composed  of  minute  cells, 
aggregated  together  in  clusters  of  various  size 
within  the  areolae  of  fibro-cellular  tissue.  The 
cells  of  adipose  tissue  are  identical  in  manner  of 
formation  with  other  cells,  being  developed  on 
nuclei  and  increasing  in  size  by  the  formation  of 
fluid  in  their  interior.  In  adipose  cells  this  fluid, 
instead  of  being  albuminous  as  in  other  cells,  is 
oleaginous,  the  oil  at  first  appearing  in  separate 
globules,  which  subsequently  coalesce  into  a  sin- 
gle drop.  The  size  of  adipose  cells  at  their  full 
development  is  about  7^  of  an  inch  in  diameter; 
when  isolated  they  are  globular  in  form,  but  are 
nexagonal  or  polyhedral  when  compressed.  They  are  perfectly  transparent, 
the  cell-membrane  being  structureless  and  their  nucleus  disappearing  as 
they  attain  their  full  size. 

SYNOVIAL  MEMBRANE  is  a  thin  membranous  layer,  which  invests  the 
articular  cartilages  of  the  bones,  and  is  thence  reflected  upon  the  surfaces 
of  the  ligaments  which  surround  and  enter  into  the  composition  of  a  joint. 
It  resembles  the  serous  membranes  in  being  a  shut  sac,  and  secretes  a 
transparent  and  viscous  fluid,  which  is  named  synovia.  Synovia  is  an 
alkaline  secretion,  containing  albumen,  which  is  coagulable  at  a  boiling 
temperature.  The  continuation  of  this  membrane  over  the  surface  of  the 
articular  cartilage,  a  much-agitated  question,  has  been  decided  by  the  in- 
teresting discoveries  of  Henle,  who  has  ascertained  the  existence  of  an 
epithelium  upon  cartilage  identical  with  that  produced  by  the  reflected 
portion  of  the  membrane.  In  some  of  the  joints  the  sy  no  vial  membrane 
is  pressed  into  the  articular  cavity  by  a  cushion  of  fat :  this  mass  was  called 
by  Havers  the  synovial  gland,  from  an  incorrect  supposition  that  it  was 
the  source  of  the  synovia ;  it  is  found  in  the  hip  and  in  the  knee-joint. 
In  the  knee-joint,  moreover,  the  synovial  membrane  forms  folds,  which 
are  most  improperly  named  ligaments,  as  the  mucous  and  alar  ligaments, 
the  two  latter  being  an  appendage  to  the  cushion  of  fat.  Besides  the 

*  Fat  vesicles,  assuming  the  polyhedral  form  from  pressure  against  one  another.  The 
capillary  vessels  are  not  represented.  From  the  omentum :  magnified  ahout  300  dia- 
meter? 


LIGAMENTS    OF    THE    TRUNK.  137 

synovial  membranes  entering  into  the  compnsi-  Fig.  71.* 

tion  of  joints,  there  are  numerous  smaller  sacs 
of  a  similar  kind  interposed  between  surfaces 
\vhich  move  upon  each  other  so  as  to  cause 
friction  ;  they  are  often  associated  with  the  arti- 
culations. These  are  the  bursts  mucosce ;  they 
are  shut  sacs,  analogous  in  structure  to  synovial 
membranes,  and  secreting  a  similar  synovial 
fluid. 

The  epithelium  of  synovial  membranes  is  of 
the  kind  termed  tessellated  ;  it  is  developed  in 
the  same  manner  with  the  epithelium  of  other 
free  surfaces,  and  is  continually  reproduced 
from  beneath,  while  the  superficial  layers  are 
being  rubbed  off  and  lost. 

ARTICULATIONS. 

The  joints  may  be  arranged,  according  to  a  natural  division,  into  those 
of  the  trunk,  those  of  the  upper  extremity,  and  those  of  the  lower 
extremity. 

LIGAMENTS  OF  THE  TRUNK. — The  articulations  of  the  trunk  are  divisible 
into  ten  groups,  viz. — 

1.  Of  the  vertebral  column. 

2.  Of  the  atlas,  with  the  occipital  bone. 

3.  Of  the  axis,  with  the  occipital  bone. 

4.  Of  the  atlas,  with  the  axis. 

5.  Of  the  lower  jaw. 

6.  Of  the  ribs,  with  the  vertebrae. 

7.  Of  the  ribs,  with  the  sternum,  and  with  each  other. 

8.  Of  the  sternum. 

9.  Of  the  vertebral  column,  with  the  pelvis. 
10.  Of  the  pelvis. 

1.  Articulation  of  the  Vertebral  Column. — The  ligaments  connecting 
together  the  different  pieces  of  the  vertebral  column,  admit  of  the  same 
arrangement  with  that  of  the  vertebrae  themselves.  Thus  the  ligaments 

Of  the  bodies  are  the — 


Anterior  common  ligament, 
Posterior  common  ligament, 
Intervertebral  substance. 
Ligamenta  subflava. 
Capsular  ligaments, 
Synovial  membranes. 
Inter-spinous, 
Supra-spinous. 
Of  the  transverse  processes, —  Inter-transverse. 


Of  the  arches, — 

Of  the  articular  processes, — 

Of  the  spinous  processes, — 


#  Epithelium  of  serous  membrane  : — At  a,  an  accidental  fold  is  represented,  the  t\vo 
dark  edges  of  which,  exhibit  the  thickness  of  the  particles,  and  of  their  nuclei,  b.  One 
of  the  oval  nuclei,  c.  Line  of  junction  between  two  particles.  Magnified  300  d'a- 
ireters. 

12,* 


138 


LIGAMENTS    OF   THE    VERTEBRAL    COLUMN. 


Fig.  72* 


Fig.  73.f 


BODIES. — The  ^Interior  common  ligament  is  a  broad  and  riband-like 
band  of  ligamentous  fibres,  extending  along  the  front  surface  of  the  verte- 
bral column,  from  the  axis  to  the  sacrum.  It  is  intimately  connected 

with  the  intervertebral  substances,  and 
less  closely  with  the  bodies  of  the  "ver- 
tebrae. In  the  dorsal  region  it  is  thicker 
than  in  the  cervical  and  lumbar,  and 
consists  of  a  median  and  two  lateral 
portions,  separated  from  each  other  by  a 
series  of  openings  for  the  passage  of 
vessels.  The  ligament  is  composed  of 
fibres  of  various  length  closely  inter- 
woven with  each  other ;  the  deeper  and 
shorter  crossing  the  intervertebral  sub- 
stances from  one  vertebra  to  the  next ; 
and  the  superficial  and  longer  fibres  crossing  three  or  four  vertebrae. 

The  anterior  common  ligament  is  in  relation  by  its  posterior  or  vertebral 
surface,  with  the  intervertebral  substances,  the  bodies  of  the  vertebra?,  and 
with  the  vessels,  principally  veins,  which  separate  its  central  from  its 
lateral  portions.  By  its  anterior  or  visceral  surface  it  is 
in  relation  in  the  neck,  wyith  the  longus  colli  muscles,  the 
pharynx  and  the  oesophagus ;  in  the  thoracic  region, 
with  the  aorta,  the  venae  azygos,  and  thoracic  duct ;  and 
in  the  lumbar  region  with  the  aorta,  right  renal  artery, 
right  lumbar  arteries,  arteria  sacra  media,  vena  cava  in- 
ferior, left  lumbar  veins,  receptaculum  chyli,  the  com- 
mencement of  the  thoracic  duct,  and  the  tendons  of  the 
lesser  muscle  of  the  diaphragm  with  the  fibres  of  which 
the  ligamentous  fibres  interlace. 

The  Posterior  common  ligament  lies  upon  the  posterior 
surface  of  the  bodies  of  the  vertebra?,  and  extends  from 
the  axis  to  the  sacrum.  It  is  broad  opposite  the  inter- 
vertebral substances,  to  which  it  is  closely  adherent ;  ana 
narrow  and  thick  over  the  bodies  of  the  vertebras,  frorc 
which  it  is  separated  by  the  veins  of  the  base  of  the  ver- 
tebrae. It  is  composed  like  the  anterior  ligament  of  shorter  and  longer 
fibres  which  are  disposed  in  a  similar  manner. 

The  posterior  common  ligament  is  in  relation  by  its  anterior  surface 
with  the  intervertebral  substances,  the  bodies  of  the  vertebras,  and  with 
the  vena?  basum  vertebrarum ;  and  by  its  posterior  surface  with  the  dura 
mater  of  the  spinal  cord,  some  loose  areolar  tissue  and  numerous  small 
veins  being  interposed. 

The  intervertebral  substance  is  a  lenticular  disc  of  fibrous  cartilage, 

*  The  anterior  ligaments  of  the  vertebrae,  and  ligaments  of  the  ribs.  1.  The  anterior 
common  ligament.  2.  The  anterior  costo-vertebral  or  stellate  ligament.  3.  The  ante- 
rior costo-transverse  ligament.  4.  The  interarticular  ligament  connecting  the  head  of 
the  rib  to  the  intervertebral  substance,  and  separating  the  two  synovial  membranes  of 
this  articulation. 

•f-  A  posterior  view  of  Aie  bodies  of  three  dorsal  vertebrae,  connected  by  their  interver- 
tebral substance  1,  1.  The  laminae  (2)  have  been  sawn  through  near  the  bodies  of  the 
vertebra^,  and  the  arches  and  processes  removed,  in  order  to  show  (3)  the  posterior 
common  ligament.  A  part  of  one  of  the  openings  in  the  posterior  surface  of  the  ver- 
tebra?, for  the  transmission  of  the  vena  basis  vertebras,  is  seen  at  4,  by  the  side  of  the 
rmrryw  and  unattached  portion  of  the  ligament. 


1.1GAMENTS    OF   THE   VERTEBRAL    COLUMN.  139 

interposed  between  each  of  the  vertebrae  from  the  axis  to  the  sacrum,  and 
retaining  them  firmly  in  connexion  with  each  other.  It  differs  in  thick 
ness  in  different  parts  of  the  column,  and  varies  in  depth  at  different  points 
of  its  extent ;  thus,  it  is  thickest  in  the  lumbar  region,  deepest  in  front  in 
the  cervical  and  lumbar  regions,  and  behind  in  the  dorsal  region ;  and 
contributes,  in  a  great  measure,  to  the  formation  of  the  natural  curves  of 
the  vertebral  column. 

When  the  intervertebral  substance  is  bisected  either  horizontally  or 
vertically,  it  is  seen  to  be  composed  of  a  series  of  layers  of  dense  fibrous 
tissue,  separated  by  interstices  filled  with  the  softer  kind.  The  central 
part  of  each  intervertebral  disc  is  wholly  made  up  of  this  softer  fibrous 
cartilage,  which  has  the  appearance  of  a  pulp,  and  is  so  elastic  as  to  rise 
above  the  level  of  the  section  as  soon  as  its  division  is  completed.  When 
examined  from  the  front,  the  layers  are  found  to  consist  of  fibres  passing 
obliquely  between  the  two  vertebras,  in  one  layer  passing  from  left  to 
right,  in  the  next  from  right  to  left,  alternating  in  each  successive  layer. 

ARCHES.  —  The  ligamenta  sub/lava  are   two 
thin  planes,  of  yellow  fibrous  tissue,  situated  be-  g'     ' 

tween  the  arches  of  each  pair  of  vertebrae,  from 
the  axis  to  the  sacrum.  From  the  imbricated 
position  of  the  lamina?  they  are  attached  to  the 
posterior  surface  of  the  vertebra  below,  and  to 
the  anterior  surface  of  the  arch  of  the  vertebra 
above,  and  are  separated  from  each  other  at  the 
middle  line  by  a  slight  interspace.  They  coun- 
teract by  their  elasticity,  the  efforts  of  the  flexor 
muscles  of  the  trunk ;  and  by  preserving  the 
upright  position  of  the  spine,  limit  the  expendi- 
ture of  muscular  force.  They  are  longer  in  the 
cervical  than  in  the  other  regions  of  the  spine,  and  are  thickest  in  the 
lumbar  region. 

The  ligamenta  subflava  are  in  relation  by  both  surfaces  with  the 
meningo-rachidian  veins,  and  internally  they  are  separated  from  the  dura 
mater  of  the  spinal  cord  by  those  *  eins  and  some  loose  areolar  and  adipose 
tissue. 

ARTICULAR  PROCESSES. — The  ligaments  of  the  articular  processes  of  the 
vertebras  are  loose  synovial  capsules  which  surround  the  articulating  sur- 
faces. They  are  protected  on  their  external  side  by  a  thin  layer  of  liga- 
mentous  fibres. 

SPINOUS  PROCESSES.  —  The  inter-spinous  ligaments  are  thin  and  mem- 
branous, and  are  extended  between  the  spinous  processes  in  the  dorsal 
and  lumbar  regions.  They  are  thickest  in  the  latter  region;  and  are  in 
relation  with  the  multifidus  spinae  muscle  at  each  side. 

The  Supra-spinous  ligament  (fig.  82)  is  a  strong  and  inelastic  fibrous 
cord,  wrhich  extends  from  the  apex  of  the  spinous  process  of  the  last  cer- 
vical vertebra  to  the  sacrum,  being  attached  to  each  spinous  process  in  its 
course  ;  it  is  thickest  in  the  lumbar  region.  The  continuation  of  this  liga- 
ment upwards  to  the  tuberosity  of  the  occipital  bone,  constitutes  the  rudi- 
mentary ligamentum  nucha3  of  man.  The  latter  is  strengthened,  as  in 

*  An  internal  view  of  the  arches  of  three  vertebrae.  To  obtain  this  view  the  lamina* 
have  been  divided  through  their  pedkles.  1.  One  of  the  ligamenta  subflava.  2  Tie 
capsular  ligament  of  one  side. 


140  LIGAMENTS    OF   THE    VERTEBRAL    COLUMN. 

animals,  by  a  thin  slip  from  the  spinous  process  of  each  of  the  cervical 
vertebrae. 

TRANSVERSE  PROCESSES.  —  The  inter-transverse  ligaments  are  thin  and 
membranous ;  they  are  found  only  between  the  transverse  processes  of  the 
lower  dorsal  vertebrae. 

2.  Articulation  of  the  Mas  with  the  Occipital  bone.  —  The  ligaments 
of  this  articulation  are  seven  in  number, — 

Two  anterior  occipito-atloid,  Posterior  occipito-atloid, 

Lateral  occipito-atloid,  Two  capsular. 

Of  the  two  anterior  ligaments,  one  is  a  rounded  cord,  situated  in  the 
middle  line,  and  superficially  to  the  other.  It  is  attached  above,  to  the 
basilar  process  of  the  occipital  bone  ;  and  below,  to  the  anterior  tubercle 
of  the  atlas.  The  deeper  ligament  is  a  broad  membranous  layer,  attached 
above,  to  the  margin  of  the  occipital  foramen ;  and  below,  1.0  the  whole 
length  of  the  anterior  arch  of  the  atlas.  It  is  in  relation  in  front  with  th« 
recti  antici  minores,  and  behind  with  the  odontoid  ligaments. 

Fig.  75.*  Fig.  7G.f 


The  posterior  ligament  is  thin  and  membranous ;  it  is  attached  above, 
to  the  margin  of  the  occipital  foramen ;  and  below,  to  the  posterior  arch 
of  the  atlas.  It  is  closely  adherent  to  the  dura  mater,  by  its  inner  surface; 
and  forms  a  ligamentous  arch  at  each  side,  for  the  passage  of  the  vertebral 
arteries  and  first  cervical  nerves.  It  is  in  relation  posteriorly  with  the  recti 
postici  minores  and  obliqui  superiores. 

The  lateral  ligaments  are  strong  fasciculi  of  ligamentous  fibres,  attached 
below,  to  the  base  of  the  transverse  process  of  the  atlas  at  each  side,  and 
above,  to  the  transverse  process  of  the  occipital  bone.  With  a  ligamentous 
expansion  derived  from  the  vaginal  process  of  the  temporal  bone,  these 

*  An  anterior  view  of  the  ligaments  connecting  the  atlas,  the  axis,  and  the  occipital 
bone.  A  transverse  section  has  been  carried  through  the  base  of  the  skull,  dividing  the 
bssilar  process  of  the  occipital  boue  and  the  petrous  portions  of  the  temporal  bones. 
1.  The  anterior  round  occipito-atloid  ligament.  2.  The  anterior  broad  occipito-atloid 
ligament.  3.  The  commencement  of  the  anterior  common  ligament.  4.  The  anterior 
atlo-axoid  ligament,  which  is  continuous  inferiorly  with  the  commencement  of  the  ante- 
rior common  ligament.  5.  One  of  the  atlo-axoid  capsular  ligaments  ;  the  one  on  the 
opposite  side  has  been  removed,  to  show  the  approximated  surfaces  of  the  articular 
processes  (G).  7.  One  of  the  occipito-atloid  capsular  ligaments.  The  most  external  of 
these  fibres  constitute  the  lateral  occipito-atloid  ligament. 

•j-  The  posterior  ligaments  of  the  occipito-atloid,  and  atlo-axoid  articulations.  1.  The 
atlas.  2.  The  axis.  3.  The  posterior  ligament  of  the  occipito-atloid  articulation.  4,  4. 
The  capsular  and  lateral  ligaments  of  this  articulation.  5.  The  posterior  ligament  of  the 
atlo-axoid  articulation.  6,  6.  Its  capsular  ligaments.  7.  The  first  of  the  ligamentum 
eubflava  passing  between  the  axis  and  the  third  cervical  vertebra.  8,  8.  The  capsular 
.igaments  of  '.hose  vertebrae. 


LIGAMENTS    OF   THE   VERTEBRAL    COLUMN.  141 

ligaments  form  a  strong  sheath  around  the  vessels  and  nerves  which  pass 
through  the  carotid  and  jugular  foramina. 

The  capsular  ligaments  are  the  thin  and  loose  ligamentous  capsules 
which  surround  the  synovial  membranes  of  the  articulations  between  the 
rondyles  of  the  occipital  bone  and  the  superior  articular  processes  of  the 
atlas.  The  ligamentous  fibres  are  most  numerous  upon  the  anterior  and 
external  part  of  the  articulation. 

The  movements  taking  place  between  the  cranium  and  atlas,  are  those 
of  flexion  and  erection,  giving  rise  to  the  forward  nodding  of  the  head. 

When  this  motion  is  increased  to  any  extent  the  whole  of  the  cervical 

,      .  "• 

region  concurs  in  its  production. 

3.  Articulation  of  the  Jlods  with  the  Occipital  bone. — The  ligaments  of 
this  articulation  are  three  in  number, — 

Occipito-axoid,  Two  odontoid. 

The  occipito-axoid  ligament  (apparatus 
ligamentosus  colli)  is  a  broad  band, 
which  covers  in  the  odontoid  process  and 
its  ligaments.  It  is  attached  below  to 
the  body  of  the  axis,  where  it  is  continu- 
ous with  the  posterior  common  ligament ; 
superiorly  it  is  inserted  by  a  broad  ex- 
pansion, into  the  basilar  groove  of  the 
occipital  bone.  It  is  firmly  connected 
opposite  the  body  of  the  axis,  with  the 
dura  mater ;  and  sometimes  is  described 
as  consisting  of  a  central  and  two  lateral 
portions ;  this,  however,  is  an  unnecessary  refinement. 

The  odontoid  ligaments  (alar)  are  two  short  and  thick  fasciculi  of  fibres, 
which  pass  outwards  from  the  apex  of  the  odontoid  process,  to  the  sides 
of  the  occipital  foramen  and  condyles.  A  third  and  smaller  fasciculus 
(Hgamentum  suspensorium),  or  middle  straight  ligament,  proceeds  from, 
the  apex  of  the  odontoid  process  to  the  anterior  margin  of  the  foramen 
magnum. 

These  ligaments  serve  to  limit  the  extent  to  which  rotation  of  the  head 
may  be  carried,  hence  they  are  termed  check  ligaments. 

4.  Articulation  of  the  Jltlas  with  the  Jixis. — The  ligaments  of  this  arti 
culation  are  jive  in  number, — 

Anterior  atlo-axoid,  Two  capsular, 

Posterior  atlo-axoid,  Transverse. 

The  anterior  ligament  consists  of  ligamentous  fibres,  which  pass  from 
the  anterior  tubercle  and  arch  of  the  atlas  to  the  base  of  the  odontoid  pro- 
cess and  body  of  the  axis,  where  they  are  continuous  with  the  commence- 
ment  of  the  anterior  common  ligament. 

*  The  upper  part  of  the  vertebral  canal,  opened  from  behind  in  order  to  show  the 
occipito-axoid  ligament.  1.  The  basilar  portion  of  the  sphenoid  bone.  2.  Section  of  thn 
occipital  bone.  3.  The  atlas,  its  posterior  arch  removed.  4.  The  axis,  the  posterior 
arch  also  removed.  5.  The  occipito-axoid  ligament,  rendered  prominent  at  its  mUdls 
by  the  projection  of  the  odontoid  process.  6.  Lateral  and  capsular  ligament  of  the  cxv 
cipito-atioid  articulation.  7.  Capsular  ligament  between  the  articulating  proi-esses  o" 
the  atlas  and  axis. 


142  *          LIGAMENTS    OF   THE    LOWER   JAW. 

The  posterior  ligament  is  a  thin  and  membranous  layer,  passing  be- 
tween the  posterior  arch  of  the  atlas  and  the  laminae  of  the  axis. 

The  capsular  ligaments  surround  the  articular  processes  of  the  atlas  and 
axis ;  they  are  loose,  to  permit  of  the  freedom  of  movement  which  sub- 
sists between  these  vertebras.  The  ligamentous  fibres  are  most  numerous 
on  the  outer  and  anterior  part  of  the  articulation,  and  the  synovial  mem- 
brane usually  communicates  with  the  synovial  cavity  between  the  trans- 
verse ligament  and  the  odontoid  process. 

The  transverse  ligament  is  a  strong  ligamentous  band,  which  arches 
across  the  area  of  the  ring  of  the  atlas  from  a  rough  tubercle  upon  the 

inner  surface  of  one  articular  process  to  a 
Fis-  78-*  similar  tubercle  on  the  other.     It  serves 

to  retain  the  odontoid  process  of  the  axis, 
in  connexion  with  the  anterior  arch  of  the 
atlas.  As  it  crosses  the  odontoid  process, 
some  fibres  are  sent  downwards  to  be  at- 
tached to  the  body  of  the  axis,  and  others 
pass  upwards  to  be  inserted  into  the  basi- 
lar  process  of  the  occipital  bone ;  hence 
the  ligament  has  a  cross-like  appearance, 
derived  from  these  appendices,  and  has 
been  denominated  cruciform.  A  synovial 

membrane  is  situated  between  the  transverse  ligament  and  the  odontoid 
process  ;  and  another  between  that  process  and  the  inner  surface  of  the 
anterior  arch  of  the  atlas. 

Actions. — It  is  the  peculiar  disposition  of  this  ligament  in  relation  to 
the  odontoid  process,  that  enables  the  atlas,  and  with  it  the  entire  cra- 
nium, to  rotate  upon  the  axis ;  the  perfect  freedom  of  movement  between 
these  bones  being  insured  by  the  two  synovial  membranes.  The  lower 
part  of  the  ring,  formed  by  the  transverse  ligament  with  the  atlas,  is 
smaller  than  the  upper,  while  the  summit  of  the  odontoid  process  is  larger 
than  its  base ;  so  that  the  process  is  still  retained  in  its  position  by  the 
transverse  ligament,  when  the  other  ligaments  are  cut  through.  The  ex- 
tent to  which  the  rotation  of  the  head  upon  the  axis  can  be  carried  is  de- 
termined by  the  odontoid  ligaments.  The  odontoid  process  with  its  liga- 
ments is  covered  in  by  the  occipito-axoid  ligament. 

5.  Jirticulation  of  the  lower  jaw. — The  lower  jaw  has  properly  but  one 
ligament,  the  external  lateral ;  the  ligaments  usually  described  are  three 
in  number ;  to  which  may  be  added,  as  appertaining  to  the  mechanism 
of  the  joint,  an  interarticular  fibrous  cartilage,  and  two  synovial  mem 
branes, — 

External  lateral,  Interarticular  fibrous-cartilage, 

Internal  lateral,  Two  synovial  membranes, 

Capsular. 

*  A  posterior  view  of  the  ligaments  connecting  the  atlas,  the  axis,  and  the  occipital 
Done.  The  posterior  part  of  the  occipital  bone  has  been  sawn  away,  and  the  arches 
of  the  atlas  and  axis  removed.  1.  The  superior  part  of  the  occipito-axoid  ligament, 
which  has  been  cut  away  in  order  to  show  the  ligaments  beneath.  2.  The  transverse 
ligament  of  the  atlas.  3,  4.  The  ascending  and  descending  slips  of  the  transverse  liga- 
ment, which  have  obtained  for  it  the  title  of  cruciform  ligament.  5.  One  of  the  odon- 
toid ligaments;  the  fellow  ligament  is  seen  on  the  opposite  side.  G.  One  of  the  occi- 
(<i«o-atloid  capsular  ligaments.  7.  One  of  the  atlo-axoid  capsular  ligaments. 


LIGAMENTS    OF    THE    LCWER   JAW. 


143 


The  external  lateral  ligament  is  a  short  aid  thick  band  of  fibres,  pass 
mg  obliquely  backwards  from  the  tubercle  of  the  zygoma,  to  the  external 
surface  of  the  neck  of  the  lower  jaw.  It  is  in  relation,  externally  with  the 
integument  of  the  face,  and  internally  with  the  two  synovial  membranes 
of  the  articulation  and  the  iriterarticular  cartilage.  The  external  lateral 
ligament  acts  conjointly  with  its  fellow  of  the  opposite  side  of  the  head  in 
the  movements  of  the  jaw. 

The  internal  lateral  ligament  has  no  connexion  with  the  articulation  of 
the  lower  jaw,  and  is  incorrectly  named  in  relation  to  the  joint;  it  is  a  thin 
aponeurotic  expansion  extending  from  the  extremity  of  the  spinous  pro- 
cess of  the  sphenoid  bone  to  the  margin  of  the  dental  foramen.  It  is 
pierced  at  its  insertion,  by  the  mylo-hyoidean  nerve. 


Fig.  79  * 


Fig.  80.f 


A  triangular  space  is  left  between  the  internal  lateral  ligament  and  the 
neck  of  the  jaw,  in  which  are  situated  the  internal  maxillary  artery  and 
auricular  nerve,  the  inferior  dental  artery  and  nerve,  and  a  part  of  the  ex- 
ternal pterygoid  muscle  ;  internally  it  is  in  relation  with  the  internal  ptery- 
goid  muscle. 

The  capsular  ligament  consists  of  a  few  irregular  ligamentous  fibres, 
which  pass  from  the  edge  of  the  glenoid  cavity  to  the  neck  of  the  lower 
jaw,  upon  the  inner  and  posterior  side  of  the  articulation.  These  fibres 
scarcely  deserve  consideration  as  a  distinct  ligament. 

The  inter  articular  fibrous  cartilage  is  a  thin  oval  plate,  thicker  at  the 
edges  than  in  the  centre,  and  placed  horizontally  between  the  head  of  the 
condyle  of  the  lower  jaw  and  the  glenoid  cavity.  It  is  connected  by  its 
outer  border  with  the  external  lateral  ligament,  and  in  front  receives  some 
fibres  of  the  external  pterygoid  muscle.  Occasionally  it  is  incomplete  in 
the  centre.  It  divides  the  joint  into  two  distinct  cavities,  the  one  being 
above  and  the  other  below  the  cartilage. 

The  synovial  membranes  are  situated  the  one  above,  the  other  below, 
the  fibrous  cartilage,  the  former  being  the  larger  of  the  two.  When  the 
fibrous  cartilage  is  perforate,  the  synovial  membranes  communicate. 

*  An  external  view  of  the  articulation  of  the  lower  jaw.  1.  The  zygomatic  arch 
2.  The  tubercle  of  the  zygoma.  3.  The  ramus  of  the  lower  jaw.  4.  The  mastoid  por 
tion  of  the  temporal  bone.  5.  The  external  lateral  ligament.  6.  The  stylo-maxillary 
.igament. 

•f  An  internal  view  of  the  articulation  of  the  lower  jaw.  1.  A  section  through  the  pe- 
trous portion  of  the  temporal  bone  and  spinous  process  of  the  sphenoid.  2.  An  internal 
view  of  the  ramus,  and  part  of  the  body  of  the  lower  jaw.  3.  The  internal  portion  of 
the  capsular  ligament.  4.  The  internal  lateral  ligament.  5.  A  small  interval  at  its  in 
sertion,  through  which  the  mylo-hyoidean  nerve  passes.  6.  The  stylo-maxillary  iiga 
inent,  a  process  of  the  deep  cervical  fascia. 


Fig.  81  * 


LIGAMENTS    OF   THE    RIBS. 

Besides  the  lower  jaw,  there  are  several  other  joints  provided  with  a 

complete  interarticular  cartilage,  rind,  con 
sequently,  with  two  synovial  membranes ; 
they  are,  the  sterno- clavicular  articulation, 
the  acromio-clavicular  and  the  articulation 
of  the  ulna  with  the  cuneiform  bone. 

The  interarticular  fibrous  cartilages  of 
the  knee-joint  are  partial,  and  there  is  but 
one  syno'vial  membrane. 

The   articulations  of  the   heads  of  the 
ribs  with  the  vertebrae  have  two  synovial 
membranes,  separated  by  an  interarticular 
ligament,  without  fibrous  cartilage.. 
Actions.  —  The  movements  of  the  lower  jaw  are  depression,  by  which 
the  mouth  is  opened ;  elevation,  by  which  it  is  closed ;  a  forward  and 
backward  movement,  and  a  movement  from  side  to  side. 

In  the  movement  of  depression,  the  interarticular  cartilage  glides  for- 
wards on  the  eminentia  articularis,  carrying  with  it  the  condyle.  If  this 
movement  be  carried  too  far,  the  superior  synovial  membrane  is  ruptured, 
and  dislocation  of  the  fibro-cartilage  with  its  condyle  into  the  zygomatic 
fossa  occurs.  In  elevation,  the  fibrous  cartilage  and  condyle  are  returned 
to  their  original  position.  The  forward  and  backward  movement  is  a 
gliding  of  the  fibro-cartilage  upon  the  glenoid  articular  surface,  in  the 
antero-posterior  direction;  and  the  movement  from  side  to  side,  in  the 
lateral  direction. 

6.  Articulation  of  the  Ribs  with  the  Vertebree.  —  The  ligaments  of  these 
articulations  are  so  strong  as  to  render  dislocation  impossible,  the  neck  of 
the  rib  would  break  before  displacement  could  occur ;  they  are  divisible 
into  two  groups : — 1.  Those  connecting  the  head  of  the  rib  \vith  the  bodies 
of  the  vertebrae ;  and,  2.  Those  connecting  the  neck  and  tubercle  of  tlie  rib 
with  the  transverse  processes.  They  are — 


Interarticular  ligament, 
Two  synovial  membranes 


1st  Group. 

Anterior  costo-vertebral  or  stellate, 
Capsular, 

2d  Group. 

Anterior  costo-transverse, 
Middle  costo-transverse, 
Posterior  costo-transverse. 

The  anterior  costo-vertebral  or  stellate  ligament  (fig.  72)  consists  of 
three  short  bands  of  ligamentous  fibres  that  radiate  from  the  anterior  part 
of  the  head  of  the  rib.  The  superior  band  passes  upwards,  and  is  attached 
to  the  vertebra  above :  the  middle  fasciculus  is  attached  to  the  interverte- 
bral  substance ;  and  the  inferior,  to  the  vertebrae  below. 

*In  this  sketch  a  section  has  been  carried  through  the  joint,  in  order  to  show  tho 
natural  position  of  the  interarticular  fibro-cartilage,  and  the  manner  in  which  it  is 
adapted  to  the  difference  of  form  of  the  articulating  surfaces.  1.  The  glenoid  fossa. 
2.  The  eminentia  articularis.  3.  The  interarticular  fibro-cartilage.  4.  The  superior 
synovial  cavity.  5.  The  inferior  synovial  cavity.  6.  An  interarticular  fibro-cartilage, 
removed  from  the  joint,  in  order  to  show  its  oval  and  concave  form ;  it  is  seen  from 
below 


LIGAMENTS    OF    THE    RIBS.  145 

lu  the  first ,  eleventh,  and  twelfth  ribs,  the  three  fasciculi  are  attached 
to  the  body  of  the  corresponding  vertebra. 

The  capsular  ligament  is  a  thin  layer  of  ligamentous  fibres,  surrounding 
the  joint  in  the  interval  left  by  the  anterior  ligament ;  it  is  thickest  above 
and  below  the  articulation,  and  protects  the  synovial  membranes. 

The  inter  articular  ligament  is  a  thin  band  which  passes  between  the 
sharp  crest  on  the  head  of  the  rib  and  the  intervertebral  substance.  It 
divides  the  joint  into  two  cavities,  which  are  each  furnished  with  a  sepa- 
rate synovial  membrane.  The  first,  eleventh,  and  twelfth  ribs  have  no 
interarticular  ligament,  and  consequently  but  one  synovial  membrane. 

The  anterior  costo-transverse  ligament  is  a  broad  band  composed  of 
several  fasciculi,  which  ascends  from  the  crest-like  ridge  on  the  neck 
of  the  rib,  to  the  transverse  process  immediately  above.  This  liga- 
ment separates  the  anterior  from  the  posterior  branch  of  the  intercostal 
nerves. 

The  middle  costo-transverse  ligament  is  a  very  strong  interosseous  liga- 
ment, passing  directly  between  the  posterior  surface  of  the  neck  of  the  rib, 
and  the  transverse  process  against  which  it  rests. 

The  posterior  costo-transverse  ligament  is  a  small  but  strong  fasciculus, 
passing  obliquely  from  the  tubercle  of  the  rib,  to  the  apex  of  the  trans- 
verse process.  The  articulation  between  the  tubercle  of  the  rib  and  the 
transverse  process  is  provided  with  a  small  synovial  membrane. 

There  is  no  anterior  costo-transverse  ligament  to  the  first  rib  ;  and  only 
rudimentary  posterior  costo-transverse  ligaments  to  the  eleventh  and 
twelfth  ribs. 

Actions.  —  The  movements  permitted  by  the  articulations  of  the  ribs, 
are  upwards  and  downwards,  and  slightly  for- 
wards and  backwards;  the  movement  increas-  Fig.  82.* 
ing  in  extent  from  the  head  to  the  extremity  of 
the  rib.     The  forward  and  backward  move- 
ment is  very  trifling  in  the  seven  superior,  but 
greater  in  the  inferior  ribs ;  the  eleventh  and 
twelfth  are  very  movable. 

7.  Articulation  of  the  Ribs  with  the  Sternum, 
and  with  each  other.  —  The  ligaments  of  the 
costo-sternal  articulations  are, — 

Anterior  costo-sternal, 
Posterior  costo-sternal, 
Superior  costo-sternal, 
Inferior  costo-sternal, 
Synovial  membranes. 

The  anterior  costo-sternal  ligament  is  a  thin  band  of  ligamentous  fibres 
that  passes  in  a  radiated  direction  from  the  extremity  of  the  costal  carti- 
lage to  the  anterior  surface  of  the  sternum,  and  intermingles  its  fibres  with 
those  of  the  ligament  of  the  opposite  side  and  with  the  tendinous  fibres  of 
origin  of  the  pectoralis  major  muscle. 

*  A  posterior  view  of  a  part  of  the  thoracic  portion  of  the  vertebral  column,  showing 
the  ligaments  connecting  the  vertebrae  with  each  other,  and  the  ribs  with  the  vertebrae 
I,  1.  The  supra-spinous  ligament.  2,  2.  The  ligamenta  subflava,  connecting  thf 
laminje  3.  The  anterior  costo-transverse  ligament.  4.  The  posterior  costo-transvprse 
ligaments. 

13  K 


l4t)  LIGAMENTS    OF    THE    PELVIS. 

The  posterior  costo-sternal  ligament  is  much  smaller  than  the  anterior, 
and  consists  only  of  a  thin  fasciculus  of  fibres  situated  on  the  posterior 
surface  of  the  articulation. 

The  superior  and  inferior  costo-sternal  ligaments  are  narrow  fasciculi 
corresponding  with  the  breadth  of  the  cartilage,  and  connecting  its  supe- 
rior and  inferior  border  with  the  side  of  the  sternum. 

The  synovial  membrane  is  absent  in  the  articulation  of  the  first  rib,  its 
cartilage  being  usually  continuous  with  the  sternum ;  that  of  the  second 
rib  has  an  interarticular  ligament,  with  two  synovial  membranes. 

The  sixth  and  seventh  ribs  have  several  fasciculi  of  strong  ligamentous 
fibres,  passing  from  the  extremity  of  their  cartilages  to  the  anterior  surface 
of  the  ensiform  cartilage,  which  latter  they  are  intended  to  support. 
They  are  named  the  costo-xiphoid  ligaments. 

The  six,  seventh,  and  eighth,  and  sometimes  the  fifth  and  the  ninth 
costal  cartilages,  have  articulations  with  each  other,  and  a  perfect  synovial 
membrane.  They  are  connected  by  ligamentous  fibres  wThich  pass  from 
one  cartilage  to  the  other,  external  and  internal  ligaments. 

The  ninth  and  tenth  are  connected  at  their  extremities  by  ligamentous 
fibres,  but  have  no  synovial  membranes. 

Actions.  —  The  movements  of  the  costo-sternal  articulations  are  very 
trifling ;  they  are  limited  to  a  slight  sliding  motion.  The  first  rib  is  the 
least,  and  the  second  the  most  movable. 

8.  Articulation  of  the  Sternum.  —  The  pieces  of  the  sternum  are  con- 
nected by  means  of  a  thin  plate  of  interosseous  cartilage  placed  between 
each,  and  by  an  anterior  and  posterior  ligament.     The  fibres  of  the  ante- 
rior sternal  ligament  are  longitudinal  in  direction,  but  so  blended  with  the 
anterior  costo-sternal  ligaments,  and  the  tendinous  fibres  of  origin  of  the 
pectoral  muscles,  as  scarcely  to  be  distinguished  as  a  distinct  ligament. 
The  posterior  sternal  ligament  is  a  broad  smooth  plane  of  longitudinal 
fibres,  placed  upon  the  posterior  surface  of  the  bone,  and  extending  from 
the  manubrium  to  the  ensiform  cartilage.     These  ligaments  contribute 
very  materially  to  the  strength  of  the  sternum  and  to  the  elasticity  of  the 
front  of  the  chest. 

9.  Articulation  of  the  Vertebral  Column  with  the  Pelvis.  —  The  last 
lumbar  vertebra  is  connected  with  the  sacrum  by  the  same  ligaments  with 
which  the  various  vertebrae  are  connected  to  each  other ;  viz.  the  anterior 
and  posterior  common  ligaments,  intervertebral  substance,  ligamenta  sub- 
flava,  capsular  ligaments,  and  inter  and  supra-spinous  ligaments. 

There  are,  however,  two  proper  ligaments  connecting  the  vertebral 
column  with  the  pelvis ;  these  are,  the 

Lumbo-sacral,  Lumbo-iliac. 

The  lumbo-sacral  ligament  is  a  thick  triangular  fasciculus  of  ligamentous 
fibres,  connected  above  with  the  transverse  process  of  the  last  lumbar  ver- 
tebra; and  below  with  the  posterior  part  of  the  upper  border  of  the 
sacrum. 

The  lumbo-iliac  ligament  passes  from  the  apex  of  the  transverse  process 
of  the  last  lumbar  vertebra  to  that  part  of  the  crest  of  the  ilium  which  sur- 
mounts the  saoro- iliac  articulation.  It  is  triangular  in  form. 

10.  The  Articulations  of  the  Pelvis. — The  ligaments  belonging  to  the 
articulations  of  the  pelvis  are  divisible  into  four  groups .  1.  Those  connect- 


LIGAMENTS    OF   THE    PELVIS.  147 

ing  the  sacrum  and  ilium ;  2.  those  passing  between  the  sacrum  and  is- 
chium,  3.  between  the  sacrum  and  coccyx  ;  and  4.  between  the  two  pubic 

bones. 

1st,  Between  the  sacrum  and  ilium. 
Sacro-iliac  anterior, 
Sacro-iliac  posterior. 

2d,  Between  the  sacrum  and  ischium. 
Sacro-ischiatic  anterior  (short), 
Sacro-ischiatic  posterior  (long). 

3d,  Between  the  sacrum  and  coccyx. 
Sacro-coccygean  anterior, 
Sacro-coccygean  posterior. 

4th,  Between  the  ossa  pubis. 
Anterior  pubic, 
Posterior  pubic, 
Superior  pubic, 
Sub-pubic, 
Interosseous  fibro-cartilage. 

1.  Between  the  Sacrum  and  Ilium. — The  anterior  sacro-iliac  ligament 
consists  of  numerous  short  ligamentous  fibres,  which  pass  from  bone  to 
bone  on  the  anterior  surface  of  the  joint. 

The  posterior  sacro-iliac  or  interosseous  ligament  is  composed  of  nu- 
merous strong  fasciculi  of  ligamentous  fibres,  which  pass  horizontally  be- 
tween the  rough  surfaces  in  the  posterior  half  of  the  sacro-iliac  articulation, 
and  constitute  the  principal  bond  of  connexion  between  the  sacrum  and 
the  ilium.  One  fasciculus  of  this  ligament,  longer  and  larger  than  the 
rest,  is  distinguished,  from  its  direction,  by  the  name  of  the  oblique  sacro- 
iliac  ligament.  It  is  attached,  by  one  extremity,  to  the  posterior  superior 
spine  of  the  ilium ;  and,  by  the  other,  to  the  third  transverse  tubercle  on 
the  posterior  surface  of  the  sacrum. 

The  surfaces  of  the  two  bones  forming  the  sacro-iliac  articulation  are 
partly  covered  with  cartilage,  and  partly  rough  and  connected  by  the  in- 
terosseous ligament.  The  anterior  or  auricular  half  is  coated  with  carti- 
lage, which  is  thicker  on  the  sacrum  than  on  the  ilium.  The  surface  of 
the  cartilage  is  irregular,  and  provided  with  a  very  delicate  synovial  mem- 
brane, which  cannot  be  demonstrated  in  the  adult ;  but  is  apparent  in  the 
young  subject,  and  in  the  female  during  pregnancy. 

2.  Between  the  Sacrum  and  Ischium. — The  anterior  or  lesser  sacro-ischi- 
atic  ligament  is  thin,  and  triangular  in  form ;  it  is  attached  by  its  apex  to 
the  spine  of  the  ischium,  and  by  its  broad  extremity  to  the  side  of  the  sa- 
crum and  coccyx,  interlacing  its  fibres  with  the  greater  sacro-ischiatic 
ligament. 

The  anterior  sacro-ischiatic  ligament  is  in  relation  in  front  with  the  coc 
cygeus  muscle,  and  behind  with  the  posterior  ligament,  with  which  its 
fibres  are  intermingled.     By  its  upper  border  it  forms  a  part  of  the  lower 
boundary  of  the  great  sacro-ischiatic  foramen,  and  by  the  lower,  a  part  of 
the  lesser  sacro-ischiatic  foramen. 


148 


LIGAMENTS    OF    THE    PELVIS. 


The  posterior  or  greater  sacro-ischiatic  ligament,  considerably  larger, 
thicker,  and  more  posterior  than  the  preceding,  is  narrower  in  the  middle 
than  at  each  extremity.  It  is  attached,  by  its  smaller  end,  to  the  inner 
margin  of  the  tuberosity  and  ramus  of  the  ischium,  where  it  forms  a  falci- 
form process,  which  protects  the  internal  pudic  artery,  and  is  continuous 
with  the  obturator  fascia.  By  its  larger  extremity  it  is  inserted  into  the  side 
of  the  coccyx,  sacrum,  and  posterior  inferior  spine  of  the  ilium. 


Fig.  83.* 


Fig.  S4.f 


The  posterior  sacro-ischiatic  ligament  is  in  relation  in  front  with  the  an- 
terior ligament,  and  behind  with  the  gluteus  maximus,  to  some  of  the 
fibres  of  which  it  gives  origin.  By  its  superior  border  it  forms  part  of  the 
lesser  ischiatic  foramen,  and  by  its  lower  border,  a  part  of  the  boundary 
of  the  perineum.  It  is  pierced  by  the  coccygeal  branch  of  the  ischiatic 
artery.  The  two  ligaments  convert  the  sacro-ischiatic  notches  into 
foramina. 

3.  Between  the  Sacrum  and  Coccyx. — The  anterior  sacro-coccygean  liga- 
ment is  a  thin  fasciculus  passing  from  the  anterior  surface  of  the  sacrum  to 
the  front  of  the  coccyx. 

The  posterior  sacro-coccygean  ligament  is  a  thick  ligamentous  layer, 
which  completes  the  lower  part  of  the  sacral  canal,  and  connects  the 

*  The  ligaments  of  the  pelvis  and  hip  joint.  1.  The  lower  part  of  the  anterior  com- 
mon ligament  of  the  vertebrae,  extending  downwards  over  the  front  of  the  sacrum.  2. 
The  lumbo-sacral  ligament.  3.  The  lumbo-iliac  ligament.  4.  The  anterior  sacro-iliac 
'igaments.  5.  The  obturator  membrane.  6.  Poupart's  ligament.  7.  Gimbernat's  liga- 
ment. 8.  The  capsular  ligament  of  the  hip-joint.  9.  The  ilio-femoral  or  accessory 
ligament. 

f  Ligaments  of  the  pelvis  and  hip  joint  The  view  is  taken  from  the  side.  1.  The 
oblique  sacro-iliac  ligament.  The  other  fasciculi  of  the  posterior  sacro-iliac  ligaments 
are  not  seen  in  this  view  of  the  pelvis.  2.  The  posterior  sacro-ischiatic  ligament.  3. 
The  anterior  sacro-ischiatic  ligament.  4.  The  great  sacro-ischiatic  foramen.  5.  The 
lesser  sacro-ischiatic  foramen.  6.  The  coty'oid  ligament  of  the  acetabuium.  7.  The 
ligamentum  tere&.  8.  The  cut  edge  of  the  capsular  ligament,  showing  its  extent  poste- 
riorly as  compaied  with  its  anterior  attachment.  9.  The  obturator  membrane  only  partly 


LIGAMENTS    OF    THE    UPPER    EXTREMITY.  149 

sacrum  with  the  coccyx  posteriorly,  extending  as  far  as  the  apex  of  the 
latter  bone. 

Between  the  two  bones  is  a  thin  disc  of  soft  fibrous  cartilage.  In 
females  there  is  frequently  a  small  synovial  membrane.  This  articulation 
admits  of  a  certain  degree  of  movement  backwards  during  parturition. 

The  ligaments  connecting  the  different  pieces  of  the  coccyx  consist  of  a 
few  scattered  anterior  and  posterior  fibres,  and  a  thin  disc  of  interosseous 
cartilage :  they  exist  only  in  the  young  subject ;  in  the  adult  the  pieces 
become  ossified. 

4.  Between  the  Ossa  Pubis.  —  The  anterior  pubic  ligament  is  composed 
of  ligamentous  fibres,  which  pass  obliquely  across  the  union  of  the  two 
bones  from  side  to  side,  and  form  an  interlacement  in  front  of  the  sym- 
physis. 

The  posterior  pubic  ligament  consists  of  a  few  irregular  fibres  uniting 
the  pubic  bones  posteriorly. 

The  superior  pubic  ligament  is  a  thick  band  of  fibres  connecting  the 
angles  of  the  pubic  bones  superiorly,  and  filling  the  inequalities  upon  the 
surface  of  the  bones. 

The  sub-pubic  ligament  is  a  thick  arch  of  fibres  connecting  the  two  bones 
inferiorly,  and  forming  the  upper  boundary  of  the  pubic  arch. 

The  interosseous  Jibro-cartilage  unites  the  two  surfaces  of  the  pubic 
bones,  in  the  same  manner  as  the  intervertebral  substance  connects  the 
bodies  of  the  vertebra?.  It  resembles  the  intervertebral  substance  also  in 
being  composed  of  oblique  fibres  disposed  in  concentric  layers,  which  are 
more  dense  towards  the  surface  than  near  the  centre.  It  is  thick  in  front, 
and  thin  behind.  A  synovial  membrane  is  sometimes  found  in  the  poste- 
rior half  of  the  articulation. 

This  articulation  becomes  movable  towards  the  latter  term  of  pregnancy, 
and  admits  of  a  slight  degree  of  separation  of  its  surfaces. 

The  obturator  ligament  or  membrane  is  not  a  ligament  of  articulation, 
but  simply  a  tendino-fibrous  membrane  stretched  across  the  obtuiator 
foramen.  It  gives  attachment  by  its  surfaces,  to  the  two  obturator  mus- 
cles, and  leaves  a  space  in  the  upper  part  of  the  foramen,  for  the  passage 
of  the  obturator  vessels  and  nerve. 

The  numerous  vacuities  in  the  walls  of  the  pelvis,  and  their  closure  by 
ligamentous  structures,  as  in  the  case  of  the  sacro-ischiatic  fissures  and 
obturator  foramina,  serve  to  diminish  very  materially  the  pressure  on  the 
soft  parts  during  the  passage  of  the  head  of  the  foetus  through  the  pelvis 
in  parturition. 

LIGAMENTS    OF    THE    UPPER   EXTREMITY. 

The  Ligaments  of  the  upper  extremity  may  be  arranged  in  the  order  ot 
the  articulations  between  the  different  bones ;  they  are,  the 

1.  Sterno-clavicular  articulation.  8.  Articulation  between  the  carpa,. 

2.  Scapulo-clavicular  articulation.  bones. 

3.  Ligaments  of  the  scapula.  9.  Carpo-metacarpal  articulation- 

4.  Shoulder  joint.  10.  Metacarpo-phalangeal     articulu- 

5.  Elbow  joint.  tion. 

6.  Radio-ulnar  articulation.  11.  Articulation  of  the  phalanges 

7.  Wrist  joint.  / 

1.  Sterno-clavicular  Articulation.  —  The  sterno-clavicular  is  an  art  In  u 
dial  articulation ;  its  ligaments  are, 
13* 


1  50  LIGAMENTS    OF   THE    UPPER    EXTREMITY. 

Anterior  sterno-clavicular, 
Posterior  sterno-clavicular, 
Inter-clavicular, 
Costo-clavicular  (rhomboid), 

Interarticular  fibro-cartilage, 

Two  synovial  membranes. 

The  anterior  sterno-clavicular  ligament  is  a  broad  ligamentous  layer, 
extending  obliquely  downwards  and  forwards,  and  covering  the  anterior 
aspect  of  the  articulation.  This  ligament  is  in  relation  by  its  anterior  sur 
face  with  the  integument  and  with  the  sternal  origin  of  the  sterno-mastoid 
muscle ;  and  behind  with  the  interarticular  nbro-cartilage  and  synovial 
membranes. 

The  posterior  sterno-clavicular  ligament  is  a  broad  fasciculus,  covering 
the  posterior  surface  of  the  articulation.  It  is  in  relation  by  its  anterior 
surface  with  the  interarticular  nbro-cartilage  and  synovia!  membranes,  and 
behind  with  the  sterno-hyoid  muscle. 

The  two  ligaments  are  continuous  at  the  upper  and  lower  part  of  the 
articulation,  so  as  to  form  a  complete  capsule  around  the  joint. 

The  interclavicular  ligament  is  a  cord-like  band  which  crosses  from  the 
extremity  of  one  clavicle  to  the  other,  and  is  closely  connected  with  the 
upper  border  of  the  sternum.  It  is  separated  by  areolar  tissue  from  the 
sterno-thyroid  muscles. 

The  costo-clavicular  ligament  (rhomboid)  is  a  thick  fasciculus  of  fibres, 
connecting  the  sternal  extremity  of  the  clavicle  with  the  cartilage  of  the 
first  rib.  It  is  situated  obliquely  between  the  rib  and  the  under  surface 
of  the  clavicle.  It  is  in  relation  in  front  with  the  tendon  of  origin  of  the 
subclavius  muscle,  and  behind  with  the  subclavian  vein. 

Actions.  —  The  movements  of  the  sterno-clavicular  articulation,  are  a 
gliding  movement  of  the  fibro-cartilage  with  the  clavicle  upon  the  articular 
surface  of  the  sternum  in  the  directions  forwards,  backwards,  upwards, 
and  downwards ;  and  circumduction.  This  articulation  is  the  centre  of 
the  movements  of  the  shoulder. 

It  is  the  rupture  of  the  rhomboid  ligament  in  dislocation  of  the  sternal 
ond  of  the  clavicle  that  gives  rise  to  the  deformity  peculiar  to  this  acci- 
dent. The    interarticular  Jibro-cartilage    is 
_.    g5<(                      nearly  circular  in  form,  and  thicker  at 
the  edges  than  in  the  centre.     It  is  at- 
tached above  to  the  clavicle ;  below  to 
the  cartilage  of  the  first  rib  ;  and  through- 
out the  rest  of  its  circumference  to  the 
anterior  and   posterior  sterno-clavicular 
ligaments ;  it  divides  the  joint  into  two 
cavities,  which  are  lined  by  distinct  sy- 
novial   membranes.      This    cartilage   is 
sometimes   pierced   through   its   centre, 
and  not  unfrequently  deficient,  to  a  greater 
or  less  extent,  in  its  lower  part. 

*  The  ligaments  of  the  sterno-clavicular  and  costo-sternal  articulations.  1.  The  ante- 
MM  sterno-clavicular  ligament.  2.  The  inter-clavicular  ligament.  3.  The  costo-clavi- 
i  iilar  or  rhomboid  ligament,  seen  on  both  sides.  4.  The  interarticular  fibro-cartilage. 
brought  into  view  by  the  removal  of  the  anterior  and  posterior  ligaments.  5.  The  an 
trri<»-  costo-sternal  ligaments  of  the  first  and  second  ribs. 


LIGAMENTS  OF  THE  SCAPULA. 


151 


•<J.  Scapula- clavicular  Articulation. - 
of  the  clavicle  are,  the 


-The  ligaments  of  tbe  scapular  end 


Superior  acromio-clavicular,  € 

Inferior  acromio-clavicular, 
Coraco-clavicular  (trapezoid  and  conoid], 

Interarticular  fibro-cartilage, 

Two  sy  no  vial  membranes. 

The  superior  acromio-clavicular  ligament  is  a  moderately  thick  plane 
of  superimposed  fibres  passing  between  the  extremity  of  the  clavicle  and 
the  acromion,  upon  the  upper  surface  of  the  joint. 

The  inferior  acromio-clavicular  ligament  is  a  thin  plane  situated  upon 
the  under  surface.  These  two  ligaments  are  continuous  with  each  other 
in  front  and  behind,  and  form  a  complete  capsule  around  the  joint. 

The  coraco-clavicular  ligament  (trapezoid,  conoid]  is  a  thick  fasciculus 
of  ligamentous  fibres,  passing  obliquely  between  the  base  of  the  coracoid 
process  and  the  under  surface  of  the  clavicle,  and  holding  the  end  of  the 
clavicle  in  firm  connexion  with  the  scapula.  When  seen  from  before,  it 
has  a  quadrilateral  form :  hence  it  is  named  trapezoid  ;  and  examined  from 
behind,  it  has  a  triangular  form,  the  base  being  upwards ;  hence  another 
name,  conoid. 

The  interarticular  fibro-cartilage  is  often  indistinct,  from  having  partial 
connexions  with  die  fibro-cartilaginous  surfaces  of  the  two  bones  between 
which  it  is  placed,  and  not  unfrequently  absent.  When  partial,  it  occu- 
pies the  upper  part  of  the  articulation.  The  synovial  membranes  are  very 
delicate.  There  is,  of  course,  but  one,  when  the  fibro-cartilage  is  incom- 
plete. 

Actions. — The  acromio-clavicular  articulation  admits  of  two  movements, 
the  gliding  of  the  surfaces  upon  each  other ;  and  the  rotation  of  the  sca- 
pula upon  the  extremity  of  the  clavicle. 

3.  The  Proper  ligaments  of  the  Scapula 
are  the  F*-86-' 

Coraco-acromial, 
Transverse. 

The  coraco-acromial  ligament  is  a  broad 
and  thick  triangular  band,  which  forms  a  pro- 
tecting arch  over  the  shoulder  joint.  It  is 
attached  by  its  apex  to  the  point  of  the  acro- 
mion process,  and  by  its  base  to  the  external 
border  of  the  coracoid  process  its  whole 
length.  This  ligament  is  in  relation  above 
with  the  under  surface  of  the  deltoid  muscle  ; 
and  below  with  the  tendon  of  the  supra-spi- 
natus  muscle,  a  bursa  mucosa  being  usually 
interposed. 

The  transverse  or  coracoid  ligament  is  a 
narrow  but  strong  fasciculus  which  crosses 

*  The  ligaments  of  the  scapula  and  shoulder  joint.  1.  The  superior  acromio-clavicu- 
lar  ligament.  2.  The  coraco-clavicular  ligament ;  this  aspect  of  the  ligament  i«  named 
trapezoid.  3.  The  coraco-acromial  ligament.  4.  The  transverse  ligament.  ;.  The 
capsular  ligament.  6.  The  coraco-humeral  ligament.  7.  The  long  tendon  of 'he  bicfpt 
issuing  from  the  capsular  ligament,  and  enter  ng  the  bicipital  groove. 


152  SHOULDER   JOINT ELBOW   JOINT. 

the  notch  in  the  upper  border  of  the  scapula,  from  the  base  of  the  cora 
coid  process,  and  converts  it  into  a  foramen.     The  supra-scapular  nerve 
passes  through  this  foramen. 

4.  Shoulder  Jotht. — The  scapulo-humeral  articulation  is  an  enarthrosis, 
or  ball-and-socket  joint — its  ligaments  are,  the 

Capsular, 

Coraco-humeral, 

Glenoid. 

The  capsular  ligament  completely  encircles  the  articulating  head  of  the 
scapula  and  the  head  of  the  humerus,  and  is  attached  to  the  neck  of  each 
bone.  It  is  thick  above,  where  resistance  is  most  required,  and  is 
strengthened  by  the  tendons  of  the  supra-spinatus,  infra-spinatus,  teres 
minor,  and  subscapularis  muscles  :  below  it  is  thin  and  loose.  The  cap- 
sule is  incomplete  at  the  point  of  contact  with  the  tendons,  so  that  they 
obtain  upon  their  inner  surface  a  covering  of  synovial  membrane. 

The  coraco-humeral  ligament  is  a  broad  band  which  descends  obliquely 
outwards  from  the  border  of  the  coracoid  process  to  the  greater  tuberosity 
of  the  humerus,  and  serves  to  strengthen  the  superior  and  anterior  part  of 
the  capsular  ligament. 

The  glenoid  ligament  is  the  prismoid  band  of  fibre-cartilage,  which  is 
attached  around  the  margin  of  the  glenoid  cavity  for  the  purposes  of  pro- 
tecting its  edges,  and  deepening  its  cavity.  It  divides  superiorly  into  two 
slips  which  are  continuous  with  the  long  tendon  of  the  biceps ;  hence  the 
ligament  is  frequently  described  as  being  formed  by  the  splitting  of  that 
tendon.  The  cavity  of  the  articulation  is  traversed  by  the  long  tendon 
of  the  biceps,  which  is  enclosed  in  a  sheath  of  synovial  membrane  in  its 
passage  through  the  joint. 

The  synovial  membrane  of  the  shoulder  joint  is  very  extensive ;  it  com- 
municates anteriorly  through  an  opening  in  the  capsular  ligament  with  a 
large  bursal  sac,  which  lines  the  under  surface  of  the  tendon  of  the  sub- 
scapularis muscle.  Superiorly,  it  frequently  communicates  through  another 
opening  in  the  capsular  ligament  with  a  bursal  sac  belonging  to  the  infra- 
spinatus  muscle ;  and  it  moreover  forms  a  sheath  around  that  portion  of 
the  tendon  of  the  biceps,  which  is  included  within  the  joint. 

The  muscles  immediately  surrounding  the  shoulder  joint  are  the  sub- 
scapularis, supra-spinatus,  infra-spinatus,  teres  minor,  long  head  of  the 
triceps  and  deltoid ;  the  long  tendon  of  the  biceps  is  within  the  capsular 
ligament. 

Actions. — The  shoulder  joint  is  capable  of  every  variety  of  motion,  viz. 
of  movement  forwards  and  backwards,  of  abduction  and  adduction,  of 
circumduction  and  rotation. 

5.  Elbow  Joint.— The  elbow  is  a  ginglymoid  articulation ;  its  ligaments 
are  four  in  number, — 

Anterior,  Internal  lateral, 

Posterior,  External  lateral. 

The  anterior  ligament  is  a  broad  and  thin  membranous  layer,  descend- 
ing from  the  anterior  surface  of  the  humerus,  immediately  above  the  joint, 
u>  the  coronoid  process  of  the  ulna  and  orbicular  ligament.  On  each  side 
it  is  connected  with  the  lateral  ligaments.  It  is  composed  of  fibres  which 
pass  ih  three  different  directions,  vertical,  transverse,  and  oblique,  the  lat- 


RADIO-ULNAR    ARTICULATION. 


153 


Fig.  87.» 


ter  being  extended  from  within  outwards  to  the  orbicular  ligament,  into 
which  they  are  attached  inferiorly.  This  ligament  is  covered  in  by  the 
brachialis  anticus  muscle. 

The  posterior  ligament  is  a  broad  and 
loose  layer  passing  between  the  posterior 
surface  of  the  humerus  and  the  anterior 
surface  of  the  base  of  the  olecranon,  and 
connected  at  each  side  with  the  lateral 
ligaments.  It  is  covered  in  by  the  ten- 
don of  the  triceps. 

The  internal  lateral  ligament  is  a  thick 
triangular  layer,  attached  above,  by  its 
apex,  to  the  internal  condyle  of  the  hu- 
merus ;  and  below,  by  its  expanded  bor- 
der, to  the  margin  of  the  greater  §igmoid 
cavity  of  the  ulna,  extending  from  the 
coronoid  process  to  the  olecranon.  At 
its  insertion  it  is  intermingled  with  some 
transverse  fibres.  The  internal  lateral 
ligament  is  in  relation  posteriorly  with 
the  ulnar  nerve. 

The  external  lateral  ligament  is  a  strong 
and  narrow  band,  which  descends  from 
the  external  condyle  of  the  humerus,  to 
be  inserted  into  the  orbicular  ligament, 

and  into  the  ridge  on  the  ulna,  with  which  the  posterior  part  of  the  latter 
ligament  is  connected.  This  ligament  is  closely  united  with  the  tenaon 
of  origin  of  the  supinator  brevis  muscle. 

The  synovial  membrane  is  extensive,  and  is  reflected  from  the  cartila- 
ginous surfaces  of  the  bones  upon  the  inner  surface  of  the  ligaments.  It 
surrounds  inferiorly  the  head  of  the  radius,  and  forms  an  articulating  sac 
between  it  and  the  lesser  sigmoid  notch. 

The  muscles  immediately  surrounding,  and  in  contact  with,  the  elbow 
joint,  are  in  front,  the  brachialis  anticus;  to  the  inner  side,  the  pronator 
radii  teres,  flexor  sublimis  digitorum,  and  flexor  carpi  ulnaris ;  externally, 
the  extensor  carpi  radialis  brevior,  extensor  cornmunis  digitorum,  entensor 
carpi  ulnaris,  anconeus,  and  supinatcr  brevis ;  and  behind,  the  triceps. 

Actions. — The  movements  of  the  elbow  joint  are  flexion  and  extension, 
which  are  performed  with  remarkable  precision.  The  extent  to  which 
these  movements  are  capable  of  being  effected,  is  limited  in  front  by  the 
coronoid  process,  and  behind  by  the  olecranon. 

6.  The  Radio-ulnar Articulation. — The  radius  and  ulnar  are  firmly  held 
together  by  ligaments  which  are  connected  with  both  extremities  of  the 
bones,  and  with  the  shaft ;  they  are,  the 


Orbicular, 

Oblique, 

Interosseous, 


Anterior  inferior, 
Posterior  inferior, 
Interarticular  fibro-cartilage. 


*  An  internal  view  of  the  ligaments  of  the  elbow  joint.  1.  The  anterior  ligament. 
2.  Tlie  internal  lateral  ligament.  3.  The  orbicular  ligament.  4.  The  oblique  ligament. 
5.  The  interosseous  ligament.  G.  The  internal  condyle  of  the  humerus,  which  coneealu 
the  posterior  ligament. 

j-  An  exterral  view  of  the  elbow  joint.     1.  The  humerus.     2.  The  ulna.     3.  The  ra 


154  RADIO-ULNAR   ARTICULATION. 

89.*  The  orbicular  ligament  (annular,  coronary)  is  a  firm 

band  several  lines  in  breadth,  which  surrounds  the 
head  of  the  radius,  and  is  attached  by  each  end  to  the 
extremities  of  the  lesser  sigmoid  cavity.  It  is  strong- 
est behind  where  it  receives  the  external  lateral  liga- 
ment, and  is  lined  on  its  inner  surface  by  a  reflection 
of  the  synovial  membrane  of  the  elbow  joint. 

The  rupture  of  this  ligament  permits  of  the  disloca- 
tion of  the  head  of  the  radius. 

The  oblique  ligament  (called  also  ligamentum  teres 
in  contradistinction  from  the  interosseous  ligament)  is 
a  narrow  slip  of  ligamentous  fibres,  descending 
obliquely  from  the  base  of  the  coronoid  process  of  the 
ulna  to  the  inner  side  of  the  radius,  a  little  below  its 
tuberosity. 

The  interosseus  ligament  is  a  broad  and  thin  plane 
of  aponeurotic  fibres  passing  obliquely  downwards  from  the  sharp  ridge 
on  the  radius  to  that  on  the  ulna.  It  is  deficient  superiorly,  is  broader 
in  the  middle  than  at  each  extremity,  and  is  perforated  at  its  lower  part 
for  the  passage  of  the  anterior  interosseous  artery.  The  posterior  interos- 
seous artery  passes  backwards  between  the  oblique  ligament  and  the  upper 
border  of  the  interosseous  ligament.  This  ligament  affords  an  extensive 
surface  for  the  attachment  of  muscles. 

The  interosseous  ligament  is  in  relation,  in  front,  with  the  flexor  pro- 
fundus  digitorum,  the  flexor  longus  pollicis,  and  pronator  quadratus  mus- 
cle, and  with  the  anterior  interosseous  artery  and  nerve  ;  and  behind  with 
the  supinator  brevis,  extensor  ossis  metacarpi  pollicis,  extensor  primi 
mternodii  pollicis,  extensor  secundi  internodii  pollicis,  and  extensor  indicis 
muscle,  and  near  the  wrist  with  the  anterior  interosseous  artery  and  pos- 
terior interosseous  nerve. 

The  anterior  inferior  ligament  is  a  thin  fasciculus  of  fibres,  passing 
transversely  between  the  radius  and  ulna. 

The  posterior  inferior  ligament  is  also  thin  and  loose,  and  nds  the  same 
disposition  on  the  posterior  surface  of  the  articulation. 

The  interarticular ,  or  triangular  fibro-cartilage,  acts  the  part  of  a  liga- 
ment between  the  lower  extremities  of  the  radius  and  ulna.  It  is 
attached  by  its  apex  to  a  depression  on  the  inner  surface  of  the  styloid 
process  of  the  ulna,  and  by  its  base  to  the  edge  of  the  radius.  This  fibro- 
cartilage  is  lined  upon  its  upper  surface  by  a  synovial  membrane,  which 
forms  a  duplicature  between  the  radius  and  ulna,  and  is  called  the  mem- 
brana  sacciformis.  By  its  lower  surface  it  enters  into  the  articulation  of 
the  wrist  joint. 

Actions. — The  movements  taking  place  between  the  radius  and  the  ulna 
are,  the  rotation  of  the  former  upon  the  latter ;  rotation  forwards  being 
termed  pronation,  and  rotation  backwards  supination.  In  these  move- 
ments the  head  of  the  radius  turns  upon  its  own  axis,  within  the  orbicular 
ligament  and  the  lesser  sigmoid  notch  of  the  ulna ;  while  inferiorly  the 

dius.  4.  The  external  lateral  ligament  inserted  inferiorly  into  (5)  the  orbicular  liga- 
ment. 6.  The  posterior  extremity  of  the  orbicular  ligament,  spreading  out  at  its  insertion 
.nto  the  ulna.  7.  The  anterior  ligament,  scarcely  apparent  in  this  view  of  the  articula- 
tion. 8.  The  posterior  ligament,  thrown  into  folds  by  the  extension  of  the  joint. 

*  1.  Articular  surface  of  olecranon  process  of  the  ulna.  2.  Coronoid  process.  3.  Or- 
bicular ligament  surrounding  the  neck  of  the  radius. 


WRIST    JOINT. 


355 


radius  presents  a  concavity  which  moves  upon  the  rounded  head  of  the 
ulna.  The  movements  of  the  radius  are  chiefly  limited  by  the  anterior 
and  posterior  inferior  ligaments,  hence  these  are  not  unfrequently  ruptured 
in  great  muscular  efforts. 

7.  Wrist  Joint.  —  The  wrist  is  a  ginglymoid  articulation  ;  the  articular 
surfaces  entering  into  its  formation  being  the  radius  and  under  surface  of 
the  triangular  fibro-cartilage  above,  and  the  rounded  surfaces  of  the 
scaphoid,  semilunar,  and  cuneiform  bone  below;  its  ligaments  are  four 
in  number,  — 

Anterior,  Internal  lateral, 

Posterior,  External  lateral. 


The  anterior  ligament  is  a  broad  and  mem- 


j-ig. 


branous  layer  consisting  of  three  fasciculi,  which 
pass  between  the  lower  part  of  the  radius  and 
the  scaphoid,  semilunar,  and  cuneiform  bone. 

The  posterior  ligament,  also  thin  and  loose, 
passes  between  the  posterior  surface  of  the  ra- 
dius, and  the  posterior  surface  of  the  semilunar 
and  cuneiform  bone. 

The  internal  lateral  ligament  extends  from' 
the  styloid  process  of  the  ulna  to  the  cuneiform 
and  pisiform  bone. 

The  external  lateral  ligament  is  attached  by 
one  extremity  to  the  styloid  process  of  the  ra- 
dius, and  by  the  other  to  the  side  of  the  scaphoid 
bone.  The  radial  artery  rests  on  this  ligament 
as  it  passes  backwards  to  the  first  metacarpal 
space. 

The  synovial  membrane  of  the  wrist  joint 
lines  the  under  surface  of  the  radius  and  inter- 
articular  cartilage  above,  and  the  first  row  of 
bones  of  the  carpus  below. 

The  relations  of  the  wrist  joint  are  the  flexor 
and  extensor  tendons  by  which  it  is  surrounded,  and  the  radial  and  ulnar 
artery. 

Actions.  —  The  movements  of  the  wrist  joint  are  flexion,  extension,  ad- 
duction, abduction,  and  circumduction.  In  these  motions  the  articular 
surfaces  glide  upon  each  other. 

*  The  ligaments  of  the  anterior  aspect  of  the  wrist  and  hand.  1.  The  lower  part  of 
the  interosseous  membrane.  2.  The  anterior  inferior  radio-ulnar  ligament.  3.  The  an- 
terior ligament  of  the  wrist  joint.  4.  Its  external  lateral  ligament.  5.  Its  internal 
lateral  ligament.  6.  The  palmar  ligaments  of  the  carpus.  7.  The  pisiform  bone  with 
its  ligaments.  8.  The  ligaments  connecting  the  second  range  of  carpal  bones  with  the 
metacarpal  and  the  metacarpal  with  each  other.  9.  The  capsular  ligament  of  the  carpo 
metacarpal  articulation  of  the  thumb.  10.  Anterior  ligament  of  the  metacarpo-pha- 
langeal  articulation  of  the  thumb.  11.  One  of  the  lateral  ligaments  of  that  articulation* 
12.  Anterior  ligament  of  the  metacarpo-phalangeal  articulation  of  the  index  finger;  this 
ligament  has  been  removed  in  the  other  fingers.  13.  Lateral  ligaments  of  the  same 
articulation  ;  the  corresponding  ligaments  are  seen  in  the  other  articulations.  14.  Trans- 
verse ligament  connecting  the  heads  of  the  metacarpal  bones  of  the  index  and  middle 
fingers;  the  same  ligament  is  seen  between  the  other  fingers.  15.  Anterior  and  one 
lateral  ligament  of  the  phalangeal  articulation  of  the  thumb.  16.  Anterior  and  latoa) 
ligaments  of  the  phalangeal  articulations  cf  the  index  finger;  the  anterior  ligaments  are 
removed  in  the  other  fingers. 


156  CARPO-METACARPAL    ARTICULATIONS 

8.  Articulations  between  the  Carpal  Bones. — These  are  amphi-arthrouial 
joints,  with  the  exception  of  the  conjoined  head  of  the  os  magnum  and 
unciforme,  which  is  received  into  a  cup  formed  by  the  scaphoid,  semi- 
lunar,  and  cuneiform  bone,  and  constitutes  an  enarthrosis.    The  ligaments 
are, 

Dorsal,  Interosseous  fibro-cartilage, 

Palmar,  Anterior  annular. 

The  dorsal  ligaments  are  ligamentous  bands,  that  pass  transversely  and 
longitudinally  from  bone  to  bone,  upon  the  dorsal  surface  of  the  carpus. 

The  palmar  ligaments  are  fasciculi  of  the  same  kind,  but  stronger  than 
the  dorsal,  having  the  like  disposition  upon  the  palmar  surface. 

The  interosseous  ligaments  are  fibro-cartilaginous  lamellae  situated  be- 
tween the  adjoining  bones  in  each  range:  in  the  upper  range  they  close 
the  upper  part  of  the  spaces  between  the  scaphoid,  semilunar,  and  cunei- 
form bones ;  in  the  lower  range  they  are  stronger  than  in  the  upper,  and 
connect  the  os  magnum  on  the  one  side  to  the  unciforme,  on  the  other  to 
the  trapezoides,  and  leave  intervals  through  which  the  synovial  membrane 
is  continued  to  the  bases  of  the  metacarpal  bones. 

The  anterior  annular  ligament  is  a  firm  ligamentous  band,  which  con- 
nects the  bones  of  the  two  sides  of  the  carpus.  It  is  attached  by  one  ex- 
tremity to  the  trapezium  and  scaphoid,  and  by  the  other  to  the  unciform 
process  of  the  unciforme  and  the  base  of  the  pisiform  bone,  and  forms  an 
arch  over  the  anterior  surface  of  the  carpus,  beneath  which  the  tendons  of 
the  long  flexors  and  the  median  nerve  pass  into  the  palm  of  the  hand. 

The  articulation  of  the  pisiform  bone  with  the  cuneiform,  is  provided 
with  a  distinct  synovial  membrane,  which  is  protected  by  fasciculi  of  liga- 
mentous fibres,  forming  a  kind  of  capsule  around  the  joint ;  they  are  in- 
serted into  the  cuneiforme,  unciforme,  and  base  of  the  metacarpal  bone  of 
the  little  finger. 

Synovial  Membranes. — There  me  five  synovial  membranes  entering  into, 
the  composition  of  the  articulations  of  the  carpus : — 

The  first  is  situated  between  the  lower  end  of  the  ulna  and  the  interar- 
ticular  fibro-cartilage ;  it  is  called  sacciform,  from  forming  a  sacculus  be- 
tween the  lateral  articulation  of  the  ulna  with  the  radius. 

The  second  is  situated  between  the  lower  surface  of  the  radius  and  in- 
terarticular  fibro-cartilage  above,  and  the  first  range  of  bones  of  the  carpus 
below. 

The  third  is  the  most  extensive  of  the  synovial  membranes  of  the  wrist ; 
it  is  situated  between  the  two  rows  of  carpal  bones,  and  passes  between 
the  bones  of  the  second  range,  to  invest  the  carpal  extremities  of  the  four 
metacarpal  bones  of  the  fingers. 

The  fourth  is  the  synovial  membrane  of  the  articulation  of  the  meta- 
carpal bone  of  the  thumb  with  the  trapezium. 

The  fifth  is  situated  between  the  pisiform  and  cuneiform  bone. 

Actions. — Very  little  movement  exists  between  the  bones  in  each  range, 
but  more  is  permitted  between  the  two  ranges.  The  motions  in  the  latter 
situation  are  those  of  flexion  and  extension. 

9.  The  Carpo-metacarpal  Articulations.  —  The  second  row  of  bones  of 
the  carpus  articulates  with  the  metacarpal  bones  of  the  four  fingers  by 
dorsal  and  palmar  ligaments ;  and  the  metacarpal  bone  of  the  thumb  with 
tne  trapezium  by  a  true  capsular  ligament.     There  is  also  in  the  carpo- 


METACARPO-PHALANGEAL  ARTICULATION. 


157 


Fig.  91.* 


mctacarpal  articulation  a  thin  interosseous  band  which  passes  Irom  the 
ulnar  edge  of  the  os  magnum  to  the  line  of  junction  between  the  third 
and  fourth  metacarpal  bones. 

The  dorsal  ligaments  are  strong  fasciculi  which  pass  from  the  second 
range  of  carpal  to  the  metacarpal  bones. 

The  palmar  ligaments  are  thin  fasciculi  arranged  upon  the  same  plan 
on  the  palmar  surface. 

The  synovial  membrane  is  a  continuation 
of  the  great  synovial  membrane  of  the  two 
rows  of  carpal  bones. 

The  capsular  ligament  of  the  thumb  is  one 
of  the  three  true  capsular  ligaments  of  the 
skeleton  ;  the  other  two  being  the  shoulder 
joint  and  hip  joint.  The  articulation  has  a 
proper  synovial  membrane. 

The  metacarpal  bones  of  the  four  fingers 
are  firmly  connected  at  their  bases  by  means 
of  dorsal  and  palmar  ligaments,  which  ex- 
tend transversely  from  one  bone  to  the  other, 
and  by  interosseous  ligaments,  which  pass 
between  their  contiguous  surfaces.  Their 
lateral  articular  facets  are  lined  by  a  reflec- 
tion of  the  great  synovial  membrane  of  the 
two  rows  of  carpal  bones. 

Actions. — The  movements  of  the  metaearpal  on  the  carpal  bones  are 
restricted  to  a  slight  degree  of  sliding  motion,  with  the  exception  of  the 
articulation  of  the  metacarpal  bone  of  the  thumb  \vith  the  trapezium.  In 
the  latter  articulation,  the  movements  are,  flexion,  extension,  adduction, 
abduction,  and  circumduction. 

10.  Metacarpo-phalangeal  Articulation.  —  The  metacarpo-phalangeal 
articulation  is  a  ginglymoid  joint ;  its  ligaments  are  four  in  number, — 

Anterior,  Two  lateral,  Transverse. 

The  anterior  ligaments  are  thick  and  fibro-cartilaginous,  and  form  part 
of  the  articulating  surface  of  the  joints.  They  are  grooved  externally  for 
the  lodgment  of  the  flexor  tendons,  and  by  their  internal  aspect  form  part 
of  the  articular  surface  for  the  head  of  the  metacarpal  bone. 

The  lateral  ligaments  are  strong  narrow  fasciculi,  holding  the  bones 
together  at  each  side. 

The  transverse  ligaments  are  strong  ligamentous  bands,  passing  between 
the  anterior  ligaments,  and  connecting  together  the  heads  of  the  meta- 
carpal bones  of  the  four  fingers. 

*  A  diagram  showing  the  disposition  of  the  five  synovial  membranes  of  the  wrist 
joint.  1.  The  sacciform  membrane.  2.  The  second  synovial  membrane.  3,  3.  The 
third,  or  large  synovial  membrane.  4.  The  synovial  membrane  .between  the  pisiform 
bone  and  the  cuneiforme.  5.  The  synovial  membrane  of  the  metacarpal  articulation  of 
the  thumb.  6.  The  lower  extremity  of  the  radius.  7.  The  lower  extremity  of  the  nlna 
8.  The  interarticular  nbro-cartilage.  £  The  scaphoid  bone.  L.  The  semilunare. 
C.  The  cuneiforme ;  the  interosseous  ligaments  are  seen  passing  between  these  three 
bones  and  separating  the  articulation  of  the  wrist  (2)  from  the  articulation  of  the  carpal 
bones  (3).  P.  The  pisiforme.  T.  The  trapezium.  2T.  The  trapezoides.  M.  The  os 
magnum.  U.  The  unciforme ;  interosseous  ligaments  are  seen  connecting  the  os  m?.jr- 
num  with  the  trapezoides  and  unciforme.  9.  The  base  of  the  metacarpal  bone  of  tin? 
thumb.  10,  10.  The  bases  of  th.3  other  metacarpal  bones. 

14 


J58  HIP   JOINT. 

The  expansion  of  the  extensor  tendon  over  the  back  of  the  fingers  take.* 
the  place  of  a  posterior  ligament. 

Actions. — This  articulation  admits  of  movement  in  four  different  direc- 
tions, viz.  of  flexion,  extension,  adduction,  and  abduction,  the  two  latter 
being  limited  to  a  small  extent.  It  is  also  capable  of  circumduction. 

11.  Articulation  of  the  Phalanges. — These  articulations  are  ginglymoid 
joints .  they  are  formed  by  three  ligaments. 

Anterior,  Two  lateral. 

The  anterior  ligament  is  firm  and  fibro-cartilaginous,  and  forms  part  of 
the  articular  surface  for  the  head  of  the  phalanges.  Externally  it  is 
grooved  for  the  reception  of  the  flexor  tendons. 

The  lateral  ligaments  are  very  strong ;  they  are  the  principal  bond  of 
connexion  between  the  bones. 

The  extensor  tendon  takes  the  place  and  performs  the  office  of  a  poste- 
rior ligament. 

Actions. — The  movements  of  the  phalangeal  joints  are  flexion  and  exten- 
sion, these  movements  being  more  extensive  between  the  first  and  second 
phalanges  than  between  the  second  and  third. 

In  connexion  with  the  phalanges,  it  may  be  proper  to  examine  certain 
fibrous  bands  termed  thecce  or  vaginal  ligaments,  which  serve  to  retain  the 
tendons  of  the  flexor  muscles  in  their  position  upon  the  flat  surface  of  their 
bones.  These  fibrous  bands  are  attached  at  each  side  to  the  lateral  mar- 
gins of  the  phalanges ;  they  are  thick  in  the  interspaces  of  the  joints,  thin 
where  the  tendons  lie  upon  the  joints,  and  they  are  lined  upon  their  inner 
surface  by  synovial  membrane. 

LIGAMENTS    OF    THE    LOWER    EXTREMITY. 

The  ligaments  of  the  lower  extremity,  like  those  of  the  upper,  may  be 
arranged  in  the  order  of  the  joints  to  which  they  belong ;  these  are,  the 

1.  Hip  joint. 

2.  Krtee  joint. 

3.  Articulation  between  the  tibia  and  fibula. 

4.  Ankle  joint. 

5.  Articulation  of  the  tarsal  bones. 

6.  Tarso-metatarsal  articulation. 

7.  Metatarso-phalangeal  articulation. 

8.  Articulation  of  the  phalanges. 

1.  Hip  Joint. — The  articulation  of  the  head  of  the  femur  with  the  ace- 
tabulum  constitutes  an  enarthrosis,  or  ball-and-socket  joint.  The  articulai 
surfaces  are  the  cup-shaped  cavity  of  the  acetabulum  and  the  rounded 
head  of  the  femur ;  the  ligaments  are  flve  in  number,  viz. 

Capsular,  Cotyloid, 

Ilio-femoral,  Transverse. 

Teres, 

The  capsular  ligament  (fig.  83,  8)  is  a  strong  ligamentous  capsule,  em- 
bracing the  acetabulum  superiorly,  and  inferiorly  the  neck  of  the  femur, 
and  connecting  the  two  bones  firmly  together.  It  is  much  thicker  upon 
the  upper  part  of  the  joint,  where  more  resistance  is  required,  than  upon 


HIP   JOINT  —  KNEE   JOINT.  159 

the  under  part,  and  extends  further  upon  the  neck  of  the  femur  on  the 
anterior  arid  superior  than  on  the  posterior  and  inferior  side,  bein°r 
attached  to  the  intertrochanteric  line  in  front,  to  the  base  of  the  great  tro- 
chanter  above,  and  to  the  middle  of  the  neck  of  the  femur  behind. 

The  ilio-femoral  ligament  (fig.  83,  9)  is  an  accessory  and  radiating 
band,  which  descends  obliquely  from  the  anterior  inferior  spinous  process 
cf  the  ilium  to  the  anterior  intertrochanteric  line,  and  strengthens  the  an- 
terior portion  of  the  capsular  ligament. 

The  ligamentum  teres  (fig.  84,  7),  triangular  in  shape,  is  attached  by  a 
round  apex  to  the  depression  just  below  the  middle  of  the  head  of  the 
femur,  and  by  its  base,  which  divides  into  two  fasciculi,  into  the  borders 
of  the  notch  of  the  acetabulum.  It  is  formed  by  a  fasciculus  of  fibres,  of 
variable  size,  surrounded  by  synovial  membrane ;  sometimes  the  synovial 
membrane  alone  exists,  or  the  ligament  is  wholly  absent. 

The  cotyloid  ligament  (fig.  84,  6)  is  a  prismoid  cord  of  fibro-cartilage, 
attached  around  the  margin  of  the  acetabulum,  and  serving  to  deepen  that 
cavity  and  protect  its  edges.  It  is  much  thicker  upon  the  upper  and  pos- 
terior border  of  the  acetabulum  than  in  front,  and  consists  of  fibres  which 
arise  from  the  whole  circumference  of  the  brim,  and  interlace  with  each 
other  at  acute  angles. 

The  transverse  ligament  is  a  strong  fasciculus  of  ligamentous  fibres, 
continuous  with  the  cotyloid  ligament,  and  extended  across  the  notch  in 
the  acetabulum.  It  converts  the  notch  into  a  foramen,  through  which  the 
articular  branches  of  the  internal  circumflex  and  obturator  arteries  enter 
the  joint. 

The  fossa  at  the  bottom  of  the  acetabulum  is  filled  by  a  mass  of  fat, 
covered  by  synovial  membrane,  which  serves  as  an  elastic  cushion  to  the 
head  of  the  bone  during  its  movements.  This  was  considered  by  Havers 
as  the  synovial  gland. 

The  synovial  membrane  is  extensive ;  it  invests  the  head  of  the  femur, 
and  is  continued  around  the  ligamentum  teres  into  the  acetabulum, 
whence  it  is  reflected  upon  the  inner  surface  of  the  capsular  ligament 
back  to  the  head  of  the  bone. 

The  muscles  immediately  surrounding  and  in  contact  with  the  hip  joint 
are,  in  front,  the  psoas  and  iliacus,  which  are  separated  from  the  capsular 
ligament  by  a  large  synovial  bursa ;  above,  the  short  head  of  the  rectus, 
and  the  gluteus  minimus;  behind,  the  pyriformis,  gemellus  superior,  obtu- 
rator internus,  gemellus  inferior,  and  quadratus  femoris  ;  and  to  the  inner 
side,  the  obturator  externus  and  pectineus. 

jjctions. — The  movements  of  the  hip  joint  are  very  extensive  ;  they  are 
flexion,  extension,  adduction,  abduction,  circumduction,  and  rotation. 

2.  Knee  Joint.  —  The  knee  is  a  ginglymoid  articulation  of  large  si/e, 
and  is  provided  with  numerous  ligaments ;  they  are  thirteen  in  number. 

Anterior  or  ligamentum  patella?,  Transverse, 

Posterior  or  ligamentum  posticum  Two  coronary. 

Winslowii,  Ligamentum  mucosum,  )  /.  , 

Internal  lateral,  Ligamenta  alaria,  y 

Two  external  lateral,  Two  semilunar  fibro-cartilagesj 

Anterior  or  external  crucial,  Synovial  membrane. 
Posterior  or  internal  crucial, 

The  first  five  are  external  to  the  articulation ;  the  next  five,  are  internal 


ICO  KNEE   JOINT. 

to  the  articulation  ;  the  remaining  three  are  mere  folds  of  synovial  mem- 
brane, and  have  no  title  to  the  name  of  ligaments.  In  addition  to  the 
ligaments,  there  are  two  fibro-cartilages,  which  are  sometimes  very  erro- 
neously considered  among  the  ligaments ;  and  a  synovial  membrane, 
which  is  still  more  improperly  named  the  capsular  ligament. 

The  anterior  ligament,  or  ligamentum  patella,  is  the  prolongation  of 
the  tendon  of  the  extensor  muscles  of  the  thigh  downwards  to  the  tubercle 
of  the  tibia.     It  is,  therefore,  no  ligament;  and,  as  we  have  before  stated, 
that  the  patella  is  simply  a  sesamoid  bone,  developed  in  the  tendon  of  the 
extensor  muscles  for  the  defence  of  the  front  of  the 
knee  joint,  the  ligamentum  patellae  has  no  title  to  con- 
\  .  sideration,  either  as  a  ligament  of  the  knee  joint  or  as  a 

ligament  of  the  patella. 

A  small  bursa  mucosa  is  situated  between  the  liga- 
mentum patella?,  near  its  insertion  and  the  front  of  the 
tibia,  and  another  of  larger  size  is  placed  between  the 
anterior  surface  of  the  patella  and  the  fascia  lata. 

The  posterior  ligament,  ligamentum  posticum  Wins- 
lowii,  is  a  broad  expansion  of  ligamentous  fibres  which 
covers  the  whole  of  the  posterior  part  of  the  joint. 
,It  is  divisible  into  two  lateral  portions  which  invest  the 
condyles  of  the  fermir,  and  a  central  portion  which  is 
depressed,  and  formed  by  the  interlacement  of  fasciculi 
passing  in  different  directions.  The  strongest  of  these 
fasciculi  is  that  which  is  derived  from  the  tendon  of  the  semi-membranosus, 
and  passes  obliquely  upwards  and  outwards,  from  the  posterior  part  of 
the  inner  tuberosity  of  the  tibia  to  the  external  condyle.  Other  accessory 
fasciculi  are  given  off  by  the  tendon  of  the  popliteus  and  by  the  heads  of 
the  gastrocnemius.  The  middle  portion  of  the  ligament  supports  the 
popliteal  artery  and  vein,  and  is  perforated  by  several  openings  for  the 
passage  of  branches  of  the  azygos  articular  artery,  and  for  the  nerves  of 
the  joint. 

The  internal  lateral  ligament  is  a  broad  and  trapezoid  layer  of  liga- 
mentous fibres,  attached  above  to  the  tubercle  on  the  internal  condyle  of 
the  femur,  and  below  to  the  side  of  the  inner  tuberosity  of  the  tibia.  It 
is  crossed  at  its  lower  part  by  the  tendons  of  the  inner  hamstring,  from 
which  it  is  separated  by  a  synovial  bursa,  and  it  covers  in  the  anterior 
slip  of  the  semi-membranosus  tendon  and  the  inferior  internal  articular 
artery. 

External  lateral  ligaments. — The  long  external  lateral  ligament  is  a 
strong  rounded  cord,  which  descends  from  the  posterior  part  of  the 
tubercle  upon  the  external  condyle  of  the  femur  to  the  outer  part  of  the 
head  of  the  fibula.  The  short  external  lateral  ligament  is  an  irregular 
fasciculus  situated  behind  the  preceding,  arising  from  the  external  condyle 
near  the  origin  of  the  head  of  the  gastrocnemius  muscle,  and  inserted  into 
the  posterior  part  of  the  head  of  the  fibula.  It  is  firmly  connected  with 
the  external  semilunar  fibro-cartilage,  and  appears  principally  intended  to 
connect  that  cartilage  with  the  fibula.  The  long  external  lateral  ligament 

*  An  anterior  view  of  the  ligaments  of  the  knee  joint.  1.  The  tendon  of  the  quadri- 
seps  extensor  muscle  ol  the  leg.  2.  The  patella.  3.  The  anterior  ligament,  or  liga- 
tnentum  patellae,  near  its  insertion.  4,  4.  The  synovial  membrane.  5.  The  internal 
*Ueral  ligament.  6.  The  long  external  lateral  ligament.  7.  The  anterior  superior  tibio- 
tiljulur  ligament. 


KNEE    JOINT. 


161 


Fig.  93.* 


is  covered  in  by  the  tendon  of  the  biceps,  and  has  passing  beneath  it  the 
tendon  of  origin  of  the  popliteus  muscle,  and  the  inferior  external  articular 
artery. 

The  true  ligaments  within  the  joint  are  the  crucial, 
transverse,  and  coronary. 

The  anterior,  or  external  crucial  ligament,  arises 
from  the  depression  upon  the  head  of  the  tibia  in  front 
of  the  spinous  process,  and  passes  upwards  and  back- 
wards to  be  inserted  into  the  inner  surface  of  the  outer 
condyle  of  the  femur,  as  far  as  its  posterior  border. 
It  is  smaller  than  the  posterior. 

The  posterior,  or  internal  crucial  ligament,  arises 
from  the  depression  upon  the  head  of  the  tibia,  behind  4. 
the  spinous  process,  and  passes  upwards  and  forwards 
to  be  inserted  into  the  inner  condyle  of  the  femur. 
This  ligament  is  less  oblique  and  larger  than  the  an- 
terior. 

The  transverse  ligament  is  a  small  slip  of  fibres 
which  extends  transversely  from  the  external  semilunar  fibro-cartilage, 
near  its  anterior  extremity,  to  the  anterior  convexity  of  the  internal 
cartilage. 

The  coronary  ligaments  are  the  short  fibres  by  which  the  convex  bor- 
ders of  the  semilunar  cartilages  are  connected  to  the  head  of  the  tibia,  and 
to  the  ligaments  surrounding  the  joint. 

The  semilunar  fibro-cartilages  are  two  falciform  plates  of  fibro-cartilage, 
situated  around  the  margin  of  the  head  of  the  tibia,  and  serving  to  deepen 
the  surface  of  articulation  for  the  condyles  of  the  femur.  They  are  thick 
along  their  convex  border,  and  thin  and  sharp  along  the  concave  edge. 

The  internal  semilunar  fibro-cartilage  forms  an  oval 
cup  for  the  reception  of  the  internal  condyle ;  it  is 
connected  by  its  convex  border  to  the  head  of  the 
tibia,  and  to  the  internal  and  posterior  ligaments,  by 
means  of  its  coronary  ligament ;  and  by  its  two  ex- 
tremities is  firmly  implanted  into  the  depressions  in 
front  and  behind  the  spinous  process.  The  external 
semilunar  fibro-cartilage  bounds  a  circular  fossa  for 
the  external  condyle :  it  is  connected  by  its  convex 
border  with  the  head  of  the  tibia,  and  to  the  external 
and  posterior  ligaments,  by  means  of  its  coronary 
ligament ;  by  its  two  extremities  it  is  inserted  into 
the  depression  between  the  two  projections  which 
constitute  the  spinous  process  of  the  tibia.  The  two 
extremities  of  the  external  cartilage  being  inserted 
into  the  same  fossa  form  almost  a  complete  circle, 

*  A  posterior  view  of  the  ligaments  of  the  knee  joint.  1.  The  fasciculus  of  the  lifja- 
mentum  posticum  Winslowii,  which  is  derived  from,  2.  the  tendon  of  the  semi-mem- 
branosus  muscle ;  the  latter  is  cut  short.  3.  The  process  of  the  tendon  which  spreads 
out  in  the  fascia  of  the  popliteus  muscle.  4.  The  process  which  is  sent  inwards  be- 
neath the  internal  lateral  ligament.  5.  The  posterior  part  of  the  internal  lateral  liga- 
ment. 6.  The  long  external  lateral  ligament.  7.  The  short  external  lateral  ligament. 
8.  The  tendon  of  the  popliteus  muscle  cut  short.  9.  The  posterior  superior  tibio-fibulat 
igament. 

•f-  The  right  knee  joint  laid  open  from  the  front,  in  order  to  show  the  internal  liga 
14*  L 


Fig.  94.f 


102  KNEE   JOINT. 

and  the  cartilage  being  somewhat  broader  than  the  internal,  nearly  covers 
the  articular  surface  of  the  tibia.  The  external  semilunar  fibro-cartilage 
besides  giving  off  a  fasciculus  from  its  anterior  border  to  constitute  the 
transverse  ligament,  is  continuous  by  some  of  its  fibres  with  the  extremity 
of  the  anterior  crucial  ligament ;  posteriorly  it  divides  into  three  slips ; 
one,  a  strong  cord,  ascends  obliquely  forwards  and  is  inserted  into  the 
anterior  part  of  the  inner  condyle  in  front  of  the  posterior  crucial  ligament ; 
another  is  the  fasciculus  of  insertion  into  the  fossa  of  the  spinous  process ; 
and  the  third,  of  small  size,  is  continuous  with  the  posterior  part  of  the 
anterior  crucial  ligament. 

The  ligamentum  mucosum  is  a  slender  conical  process  of  synovial 
membrane  enclosing  a  few  ligamentous  fibres  which  proceed  from  the 
transverse  ligament.  It  is  connected,  by  its  apex,  with  the  anterior  part 
of  the  condyloid  notch,  and  by  its  base  is  lost  in  the  mass  of  fat  which 
projects  into  the  joint  beneath  the  patella. 

The  alar  ligaments  are  two  fringed  folds  of  sy- 
Fig.  95.*  novial  membrane,  extending  from  the  ligamentum 

mucosum,  along  the  edges  of  the  mass  of  fat  to 
the  sides  of  the  patella. 

The  synovial  membrane  of  the  knee  joint  is  by 
far  the  most  extensive  in  the  skeleton.  It  invests 
the  cartilaginous  surfaces  of  the  condyles  of  the 
femur,  of  the  head  of  the  tibia,  and  of  the  inner 
surface  of  the  patella ;  it  covers  both  surfaces  of 
the  semilunar  fibro-cartilages,  and  is  reflected 
upon  the  crucial  ligaments,  and  upon  the  innei 
surface  of  the  ligaments  which  form  the  circumfe- 
rence of  the  joint.  On  each  side  of  the  patella,  it 
lines  the  tendinous  aponeuroses  of  the  vastus  inter- 
nus  and  vastus  externus  muscles,  and  forms  a 
pouch  of  considerable  size  between  the  extensor 
tendon  and  the  front  of  the  femur.  It  also  forms 

merits.  1.  The  cartilaginous  surface  of  the  lower  extremity  of  the  femur  with  its  two 
condyl<.s;  the  figure  5  rests  upon  the  external;  the  figure  3  upon  the  internal  condyle. 
2.  The  anterior  crucial  ligament.  3.  The  posterior  crucial  ligament.  4.  The  trnnsv^rse 
ligament.  5.  The  attachment  of  the  ligamentum  mucosum  ;  the  rest  has  been  removed. 
6.  The  internal  semilunar  fibro-cartilage.  7.  The  external  fibro-cartilage.  8.  A  part  of 
the  ligamentum  patellae  turned  down.  9.  The  bursa,  situated  between  the  ligamentum 
patellse  and  the  head  of  the  tibia ;  it  has  been  laid  open.  10.  The  anterior  superior 
tibio-fibular  ligament.  11.  The  upper  part  of  the  interosseous  membrane;  the  opening 
above  this  membrane  is  for  the  passage  of  the  anterior  tibial  artery. 

j-  A  longitudinal  section  of  the  left  knee  joint,  showing  the  reflection  of  its  synovial 
membrane.  1.  The  cancellous  structure  of  the  lower  part  of  the  femur.  2.  The  tendon 
(if  the  extensor  muscles  of  the  leg.  3.  The  patella.  4.  The  ligamentum  patellae.  h. 
The  cancellous  structure  of  the  head  of  the  tibia.  6.  A  bursa  situated  between  the 
ligamentum  pate! las  and  the  head  of  the  tibia.  7.  The  mass  of  fat  projecting  into  the 
cavity  of  the  joint  below  the  patella.  **  The  synovial  membrane.  8.  The  pouch 
of  synovial  membrane  which  ascends  between  the  tendon  of  the  extensor  muscles  of 
the  leg,  and  the  front  of  the  lower  extremity  of  the  femur.  9.  One  of  the  alar  liga- 
ments; the  other  has  been  removed  with  the  opposite  section.  10.  The  ligamentum 
mucosum  left  entire;  the  section  being  made  to  its  inner  side.  11.  The  anterior  or 
external  crucial  ligament.  12.  The  posterior  ligament.  The  scheme  of  the  synovial 
membrane,  which  is  here  presented  to  the  student,  is  divested  of  all  unnecessary  com- 
plications. It  may  be  traced  from  the  sacculus  (at  S),  along  the  inner  surface  of  the 
patella  ;  then  over  the  adipose  mass  (7),  from  which  it  throws  off  the  mucous  li^a 
•rent  (1U)  ;  then  over  the  head  of  the  tibia,  forming  a  sheath  to  the  crucial  ligamen.s ; 
i»en  upwards  along  the  posterior  ligament  and  condyles  of  the  femur  to  the  sacduus, 
wnenoe  its  examination  commenced. 


TIB1O-FIBULAR   ARTICULATIONS.  163 

.he  folds  m  the  interior  of  the  joint,  called  "  ligamentum  mucosura,"  and 
"  ligamenta  alaria."  The  superior  pouch  of  the  synovial  membrane  is 
supported  and  raised  during  the  movements  of  the  limb  by  a  small  muscle, 
the  subcmreus,  which  is  inserted  into  it. 

Between  the  ligamentum  patellae  and  the  synovial  membrane  is  a  con- 
siderable mass  of  fat,  which  presses  the  membrane  towards  the  interior  of 
the  joint,  and  occupies  the  fossa  between  the  two  condyles. 

Besides  the  proper  ligaments  of  the  articulation,  the  joint  is  protected 
on  its  anterior  part  by  the  fascia  lata,  which  is  thicker  upon  the  outer  than 
upon  the  inner  side,  by  a  tendinous  expansion  from  the  vastus  internus, 
and  by  some  scattered  ligamentous  fibres  which  are  inserted  into  the  sides 
of  the  patella. 

Actions. — The  knee  joint  is  one  of  the  strongest  of  the  articulations  of 
the  body,  while  at  the  same  time  it  admits  of  the  most  perfect  degree  of 
movement  in  the  directions  of  flexion  and  extension.  During  flexion,  the 
articular  surface  of  the  tibia  glides  forward  on  the  condyles  of  the  femur, 
the  lateral  ligaments,  the  posterior,  and  the  crucial  ligaments  are  relaxed, 
while  the  ligamentum  patellae  being  put  upon  the  stretch,  serves  to  press 
the  adipose  mass  into  the  vacuity  formed  in  the  front  of  the  joint.  In 
extension,  all  the  ligaments  are  put  upon  the  stretch,  with  the  exception 
of  the  ligamentum  patellae.  When  the  knee  is  semi-flexed,  a  partial  de- 
gree of  rotation  is  permitted. 

3.  Articulation  between  the  Tibia  and  Fibula. — The  tibia  and  fibula  are 
held  firmly  connected  by  means  of  seven  ligaments,  viz. 

Anterior,    )    ,  Interosseous  membrane, 

Posterior,  $  Interosseous  inferior, 

Anterior,   )  ,    ,  Transverse. 

•   '   >  below. 
Posterior,  ^ 

The  anterior  superior  ligament  is  a  strong  fasciculus  of  parallel  fibres, 
passing  obliquely  downwards  and  outwards  from  the  inner  tuberosity  of 
the  tibia,  to  the  anterior  surface  of  the  head  of  the  fibula. 

The  posterior  superior  ligament  is  disposed  in  a  similar  manner  upon 
the  posterior  surface  of  the  joint. 

Within  the  articulation  there  is  a  distinct  synovial  membrane  which  is 
sometimes  continuous  with  that  of  the  knee  joint. 

The  interosseous  membrane  or  superior  Interosseous  ligament  is  a  broad 
layer  of  aponeurotic  fibres  which  pass  obliquely  downwards  and  outwards, 
from  the  sharp  ridge  on  the  tibia  to  the  inner  edge  of  the  fibula,  and  are 
crossed  at  an  acute  angle  by  a  few  fibres  passing  in  the  opposite  direction. 
The  ligament  is  deficient  above,  leaving  a  considerable  interval  between 
the  bones,  through  which  the  anterior  tibial  artery  takes  its  course  for- 
wards to  the  anterior  aspect  of  the  leg,  and  near  its  lower  third  there  is 
an  opening  for  the  anterior  peroneal  artery  and  vein. 

The  interosseous  membrane  is  in  relation,  in  front,  with  the  tibialis 
anticus,  extensor  longus  digitorum,  and  extensor  proprius  pollicis  muscle, 
with  the  anterior  tibial  vessels  and  nerve,  and  with  the  anterior  peronea* 
artery ;  and  behind,  with  the  tibialis  posticus,  and  flexor  longus  digitorum 
muscle,  and  with  the  posterior  peroneal  artery. 

The  inferior  interosseous  ligament  consists  of  short  and  strong  fibres, 
which  hold  the  bones  firmly  together  inferiorly,  where  they  are  nearly  ,n 


164 


ANKLE   JOINT. 


contact.     This  articulation  is  so  firm  that  the  fibula  is  likely  to  be  broken 
in  the  attempt  to  rupture  the  ligament. 

The  anterior  inferior  ligament  is  a  broad  band,  consisting  of  two  fasci 
culi'of  parallel  fibres  which  pass  obliquely  across  the  anterior  aspect  of 
the  articulation  of  the  two  bones  at  their  inferior  extremity,  from  the  tibia 
to  the  fibula. 

The  posterior  inferior  ligament  (fig.  98,  2)  is  a  similar  band  upon  th 
posterior  surface  of  the  articulation.  Both  ligaments  project  somewha 
below  the  margin  of  the  bones,  and  serve  to  deepen  the  cavity  of  articu 
lation  for  the  astragalus. 

The  transverse  ligament  (fig.  98,  3)  is  a  narrow  band  of  ligamentous 
fibres,  continuous  with  the  preceding,  and  passing  transversely  across  the 
back  of  the  ankle  joint  between  the  two  malleoli. 

The  synovial  membrane  of  the  inferior  tibio-fibular  articulation,  is  a 
duplicature  of  the  synovial  membrane  of  the  ankle  joint  reflected  upwards 
for  a  short  distance  between  the  two  bones. 

Actions. — An  obscure  degree  of  movement  exists  between  the  tibia  and 
fibula,  which  is  principally  calculated  to  enable  the  latter  to  resist  injury, 
by  yielding  for  a  trifling  extent  to  the  pressure  exerted. 

4.  Jlnkle  joint. — The  ankle  is  a  ginglymoid  articulation  ;  the  surfaces 
entering  into  its  formation  are  the  under  surface  of  the  tibia  with  its  mal- 
leolus  and  the  malleolus  of  the  fibula,  above,  and  the  surface  of  the  astra- 
galus with  its  two  lateral  facets,  below.  The  ligaments  are  three  in 
number : 

Anterior,  Internal  lateral,  External  lateral. 

The  anterior  ligament  is  a  thin  membranous  layer,  passing  from  the 
margin  of  the  tibia  to  the  astragalus  in  front  of  the  articular  surface.  It 
is  in  relation,  in  front,  with  the  extensor  tendons  of  the  great  and  lesser 
toes,  with  the  tendons  of  the  tibialis  anticus  and  peroneus  tertius,  and  with 
the  anterior  tibial  vessels  and  nerve.  Posteriorly  it  lies  in  contact  with 
the  extra-synovial  adipose  tissue  and  with  the  synovial  membrane. 


Fig.  96  * 


Fig.  97.f 


•An  internal  view  of  the  ankle  joint.  1.  The  internal  malleolus  of  the  tibia.  2,  2 
Pait  of  the  astragalus:  the  rest  is  concealed  by  the  ligaments.  3.  The  os  calcis.  4.  The 
bcaphoid  bone.  5.  The  internal  cuneiform  bone.  6.  The  internal  lateral  or  deltoid 
ligament.  7.  The  anterior  ligament.  8.  The  tendo  Achillis  ;  a  small  bursa  is  seen 
interposed  between  the  tendon  and  the  tuberosity  of  the  os  calcis. 

•(•An  external  view  of  the  ankle-joint.  1.  The  tibia.  2.  The  external  malleolus  of 
the  fibula.  3,  3.  The  astragalus.  4.  The  os  calcis.  5.  The  cuboid  bone.  6.  The  ante- 
rior fasciculus  of  the  external  lateral  ligament  attached  to  the  astragalus.  7.  Its  middle 
insruoulus,  attached  to  the  os  calcis.  8.  Its  posterior  fasciculus,  attached  to  the  astra 
ftit!n»  Q.  The  anterior  ligament  of  the  ankle. 


TARSAL    ARTICULATIONS.  165 

The  internal  lateral  or  deltoid  ligament  is  a  triangular  layer  of  fibres, 
attached  superiorly  by  its  apex  to  the  internal  raalleolus,  and  inferiorly  by 
an  expanded  -base  to  the  astragalus,  os  calcis,  and  scaphoid  bone.  Be- 
neath the  superficial  layer  of  this  ligament  is  a  much  stronger  and  thicker 
fasciculus,  which  connects  the  apex  of  the  internal  malleolus  with  the  side 
of  the  astragalus. 

This  internal  lateral  ligament  is  covered  in  and  partly  concealed  by  the 
tendon  of  the  tibialis  posticus,  and  at  its  posterior  part  is  in  relation  with 
the  tendon  of  the  flexor  longus  digitorum,  and  with  that  of  the  flexor 
longus  pollicis. 

The  external  lateral  ligament  consists  of  three  strong  fasciculi,  which 
proceed  from  the  inner  side  of  the  external  malleolus,  and  diverge  in  three 
different  directions.  The  anterior  fasciculus  passes  forwards,  and  is 
attached  to  the  astragalus ;  the  posterior,  backwards,  and  is  connected 
with  the  astragalus  posteriorly ;  and  the  middle,  longer  than  the  other  two, 
descends  to  be  inserted  into  the  outer  side  of  the  os  calcis. 

"  It  is  the  strong  union  of  this  bone,"  says  Sir  Astley  Cooper,  "  with 
the  tarsal  bones,  by  means  of  the  external  lateral  ligaments,  which  leads 
to  its  being  more  frequently  fractured  than  dislocated." 

The  transverse  ligament  of  the  tibia  and  fibula  occupies  the  place  of  a 
posterior  ligament.  It  is  in  relation,  behi?id,  with  the  posterior  tibial  ves- 
sels and  nerve,  and  with  the  tendon  of  the  tibialis  posticus  muscle ;  and 
in  front,  with  the  extra-synovial  adipose  tissue,  and  synovia!  membrane. 

The  Synovial  membrane  invests  the  cartilaginous  surfaces  of  the  tibia 
and  fibula  (sending  a  duplicate  upwards  between  their  lower  ends),  and 
the  upper  surface  and  two  sides  of  the  astragalus.  It  is  then  reflected 
upon  the  anterior  and  lateral  ligaments,  and  upon  the  transverse  ligament 
posteriorly. 

Actions.  —  The  movements  of  the  ankle  joint  are  flexion  and  extension 
only,  without  lateral  motion. 

5.  Articulations  of  the  Tarsal  Bones.  —  The  ligaments  which  connect 
the  seven  bones  of  the  tarsus  to  each  other  are  of  three  kinds, — 

Dorsal,  Plantar,  Interosseous. 

The  dorsal  ligaments  are  small  fasciculi  of  parallel  fibres,  which  pass 
from  each  bone  to  all  the  neighbouring  bones  with  which  it  articulates. 
The  only  dorsal  ligaments  deserving  of  particular  mention  are,  the  external 
and  posterior  calcaneo-astragaloid,  which,  with  the  interosseous  ligament, 
complete  the  articulation  of  the  astragalus  writh  the  os  calcis ;  the  superior 
and  internal  calcaneo-cuboid  ligament.  The  internal  calcaneo-cuboid  and 
the  superior  calcaneo-scaphoid  ligament,  -which  are  closely  united  pos- 
teriorly in  the  deep  groove  which  intervenes  between  the  astragalus  and 
os  calcis,  separate  anteriorly  to  reach  their  respective  bones ;  they  form 
the  principal  bond  of  connexion  between  the  first  and  second  range  of 
the  bones  of  the  foot.  It  is  the  division  of  this  portion  of  these  ligaments 
that  demands  the  especial  attention  of  the  surgeon  in  performing  Chopart's 
operation. 

The  plantar  ligaments  have  the  same  disposition  on  the  plantar  surface 
of  the  foot;  three  of  them,  however,  are  of  a  large  size,  and  have  especial 
names,  viz.  the 

Calcaneo-scaphoid         Long  calcaneo-cuboid,        Short  calcaneo-cuboid. 


166  TARSAL   ARTICULATIONS. 

The  inferior  calcaneo-scaphoid  ligament  is  a  broad  and  fibro-cartilaginous 
band  of  ligament,  which  passes  forwards  from  the  anterior  and  inner  bor- 
der of  the  os  calcis  and  scaphoid  bone.  In  addition  to 
connecting  the  os  calcis  and  scaphoid,  it  supports  the 
astragalus,  and  forms  part  of  the  cavity  in  which  the 
rounded  head  of  the  latter  bone  is  received.  It  is  lined 
upon  its  upper  surface  by  the  synovial  membrane  of  the 
astragalo-scaphoid  articulation. 

The  firm  connexion  of  the  os  calcis  with  the  scaphoid 
bone,  and  the  feebleness  of  the  astragalo-scaphoid  articu- 
lation, are  conditions  favourable  to  the  occasional  disloca- 
tion of  the  head  of  the  astragalus. 

The  long  calcaneo- cuboid  ligamentum,  or  longum  planta, 
is  a  long  band  of  ligamentous  fibres,  which  proceeds  from 
the  under  surface  of  the  os  calcis  to  the  rough  surface  on 
the  under  part  of  the  cuboid  bone,  its  fibres  being  con- 
tinued onwards  to  the  bases  of  the  third  and  fourth  metatarsal  bones. 

This  ligament  forms  the  inferior  boundary  of  a  canal  in  the  cuboid 
bone,  through  which  the  tendon  of  the  peroneus  longus  passes  to  its  in- 
sertion in  the  base  of  the  metatarsal  bone  of  the  great  toe. 

The  short  calcaneo-cuboid,  or  ligamentum  breve  planta,  is  situated 
nearer  to  the  bones  than  the  long  plantar  ligament,  from  which  it  is  sepa- 
rated by  adipose  tissue;  it  is  broa  1  and  extensive,  and  ties  the  under 
surfaces  of  the  os  calcis  and  cuboid  bone  firmly  together. 

The  interosseous  ligaments  are  five  in  number;  they  are  short  and  strong 
ligamentous  fibres  situated  between  adjoining  bones,  and  firmly  attached 
to  their  rough  surfaces.  One  of  these,  the  calcaneo-astragaloid,  is  lodged 
in  the  groove  between  the  upper  surface  of  the  os  calcis  and  the  lower 
of  the  astragalus.  It  is  large  and  very  strong,  consists  of  vertical  and 
oblique  fibres,  and  serves  to  unite  the  os  calcis  and  astragalus  solidly 
together.  The  second  interosseous  ligament,  also  very  strong,  is  situated 
between  the  sides  of  the  scaphoid  and  cuboid  bone ;  while  the  three  re- 
maining interosseous  ligaments  connect  strongly  together  the  three  cunei- 
form bones  and  the  cuboid. 

The  synovial  membranes  of  the  tarsus  are  four  in  number ;  one  for  the 
posterior  calcaneo-astragaloid  articulation  ;  a  second,  for  the  anterior  cal- 
caneo-astragaloid and  astragalo-scaphoid  articulation.  Occasionally  an 
additional  small  synovial  membrane  is  found  in  the  anterior  calcaneo- 
astragaloid  joint ;  a  thirdy  for  the  calcaneo-cuboid  articulation  ;  and  a 
fourth,  the  large  tarsal  synovial  membrane,  for  the  articulations  between 
the  scaphoid  and  three  cuneiform  bones,  the  cuneiform  bones  with  each 
other,  the  external  cuneiform  bone  with  the  cuboid,  and  the  two  external 
cuneiform  bones  \vith  the  bases  of  the  second  and  third  metatarsal  bones. 
The  prolongation  which  reaches  the  metatarsal  bones  passes  forwards  be- 
tween the  internal  and  middle  cuneiform  bones.  A  small  synovial  mem- 
brane is  sometimes  met  with  between  the  contiguous  surfaces  of  the 
scaphoid  and  cuboid  bone. 

*  A  posterior  view  of  the  ankle  joint.  1.  The  lower  part  of  the  interosseous  mem- 
brane. 2.  The  posterior  inferior  ligament  connecting  the  tibia  and  fibula.  3.  The 
transverse  ligament.  4.  The  internal  lateral  ligament.  5.  The  posterior  fasciculus  of 
tne  internal  lateral  ligament.  6.  The  middle  fasciculus  of  the  external  lateral  ligament 
7  The  synovial  membrane  of  the  ankle  joint.  8.  The  os  calcis. 


TARSO-METATARSAL    ARTICULATION. 


16' 


Fig.  99. 


Actions.  —  The  movements  permitted  by  the  articulation  between  the 
astragalus  and  os  calcis,  are  a  slight  degree  of  gliding,  in  the  directions 
forwards  and  backwards  and  laterally  from  side  to  side.  The  movements 
of  the  second  range  of  tarsal  bones  is  very  trifling,  being  greater  between 
the  scaphoid  and  three  cuneiform  bones  than  in  the  other  articulations. 
The  movements  occurring  between  the  first  and  second  rano-e  are  the 
most  considerable ;  they  are  adduction  and  abduction,  and,  in  a  minor 
degree,  flexion,  which  increases  the  arch  of  the  foot,  and  extension,  which 
flattens  the  arch. 

6.  Tarso-metatarsal  Articulation. — The  ligaments  of  this  articulation  are, 

Dorsal,  Plantar,  Interosseous. 

The  dorsal  ligaments  connect  the  metatarsal  to  the  tarsal  bones,  and 
the  metatarsal  bones  with  each  other.  The  precise  arrangement  of  these 
ligaments  is  of  little  importance,  but  it  may  be  remarked,  that  the  base 
of  the  second  metatarsal  bone,  articulating  with  the  three  cuneiform  bones, 
receives  a  ligamentous  slip  from  each,  while  the  rest,  articulating  with  a 
single  tarsal  bone,  receive  only  a  single  tarsal  slip. 

The  plantar  ligaments  have  the  same  disposition  on 
the  plantar  surface. 

The  interosseous  ligaments  are  situated  between  the 
bases  of  the  metatarsal  bones  of  the  four  lesser  toes ; 
and  also  between  the  bases  of  the  second  and  third 
metatarsal  bones,  and  the  internal  and  external  cunei- 
form bones. 

The  metatarsal  bone  of  the  second  toe  is  implanted 
by  its  base  between  the  internal  and  external  cuneiform 
bones,  and  is  the  most  strongly  articulated  of  all  the 
metatarsal  bones.  This  disposition  must  be  recollected 
in  amputation  at  the  tarso-metatarsal  articulation. 

The  synovial  membranes  of  this  articulation  are  three 
in  number :  one  for  the  metatarsal  bone  of  the  great 
toe ;  one  for  the  second  and  third  metatarsal  bones, 
which  is  continuous  with  the  great  tarsal  synovial  mem- 
brane ;  and  one  for  the  fourth  and  fifth  metatarsal 
bones. 

Actions.  —  The  movements  of  the  metatarsal  bones 
upon  the  tarsal,  and  upon  each  other,  are  very  slight ; 
they  are  such  only  as  contribute  to  the  strength  of  the 
foot  by  permitting  of  a  certain  degree  of  yielding  to  opposing  forces. 

7.  Metatarsal-phalangeal  Articulation. — The  ligaments  of  this  articu!*. 
tion,  like  those  of  the  articulation  between  the  first  phalanges  and  meta- 
carpal  bones  of  the  hand,  are, 


Anterior  or  plantar, 


Two  lateral, 


Transverse. 


•  The  ligaments  of  the  sole  of  the  foot.  1.  The  os  calcis.  2.  The  astragalus.  3.  The 
tuberosity  of  the  scaphoid  bone.  4.  The  long  calcaneo-cuboid  ligament.  5.  Part  of  the 
short  calcaneo-cuboid  ligament.  6.  The  calcaneo-scaphoid  ligament.  7.  The  plantar 
tarsal  ligaments.  8,  8.  The  tendon  of  the  peroneus  longus  muscle.  9,  9.  Plantar  tarso- 
metatarsal  ligaments.  10.  Plantar  ligament  of  the  metatarso-phalangeal  articulation  of 
the  great  toe ;  the  same  ligament  is  seen  upon  the  other  toes.  11.  Lateral  ligaments  of 
the  metatarso-phalangeal  articulation.  12.  Transverse  ligament.  13.  The  lateral  liga 
ments  of  the  phalanges  of  the  great  toe;  the  same  ligaments  are  seen  upon  the  otfio: 
toes. 


J68  STRUCTURE    OF    MUSCLE. 

The  anterior  or  plantar  ligaments  are  thick  and  fibro-cartilaginous,  and 
form  part  of  the  articulating  surface  of  the  joint. 

The  lateral  ligaments  are  short  and  very  strong,  and  situated  on  each 
side  of  the  joints. 

The  transverse  ligaments  are  strong  bands,  which  pass  transversely  be- 
tween the  anterior  ligaments. 

The  expansion  of  the  extensor  tendon  supplies  the  place  of  a  dorsal 
ligament. 

Actions.  —  The  movements  of  the  first  phalanges  upon  the  rounded 
heads  of  the  metatarsal  bones,  are  ^/Z&rion,  extension,  adduction  and  abduc- 
tion. 

8.  Articulation  of  the  Phalanges. — The  ligaments  of  the  phalanges  are 
the  same  as  those  of  the  fingers,  and  have  the  same  disposition ;  their 
actions  are  also  similar.  They  are, 

Anterior  or  plantar,  Two  lateral. 


CHAPTER    IV. 

ON  THE  MUSCLES. 

MUSCLES  are  the  moving  organs  of  the  animal  frame ;  they  constitute 
by  their  size  and  number  the  great  bulk  of  the  body,  upon  which  they 
bestow  form  and  symmetry.  In  the  limbs  they  are  situated  around  the 
bones,  which  they  invest  and  defend,  while  they  form  to  some  of  the  joints 
a  principal  protection.  In  the  trunk  they  are  spread  out  to  enclose  cavi- 
ties, and  constitute  a  defensive  wall  capable  of  yielding  to  internal  pressure, 
and  again  returning  to  its  original  position. 

Their  colour  presents  the  deep  red  which  is  characteristic  of  flesh,  and 
their  form  is  variously  modified,  to  execute  the  varied  range  of  movements 
which  they  are  required  to  effect. 

Muscle  is  composed  of  a  number  of  parallel  fibres  placed  side  by  side, 
and  supported  and  held  together  by  a  delicate  web  of  areolar  tissue ;  so 
that,  if  it  were  possible  to  remove  the  muscular  substance,  we  should  have 
remaining  a  beautiful  reticular  framework,  possessing  the  exact  form  and 
size  of  the  muscle  without  its  colour  and  solidity.  Towards  the  extremity 
of  the  organ  the  muscular  fibre  ceases,  and  the  areolar  structure  becomes 
aggregated  and  modified,  so  as  to  constitute  those  glistening  fibres  and 
cords  by  which  the  muscle  is  tied  to  the  surface  of  bone,  and  which  are 
called  tendons.  Almost  every  muscle  in  the  body  is  connected  with  bone, 
either  by  tendinous  fibres,  or  by  an  aggregation  of  those  fibres  constituting 
a  tendon ;  and  the  union  is  so  firm,  that,  under  extreme  violence,  the 
bone  itself  rather  breaks  than  permits  of  the  separation  of  the  tendon  from 
its  attachment.  In  the  broad  muscles  the  tendon  is  spread  so  as  to  form 
an  expansion,  called  aponeurosis  (d#o,  longe;  vsupov,*  nervus  —  a  nerve 
widely  spread  ouf). 

Muscles  present  various  modifications  in  the  arrangement  of  their  fibres 
in  relation  to  their  tendinous  structure.  Sometimes  they  are  completely 

*  The  ancients  named  all  the  white  fibres  of  the  body  vtvpa ;  the  term  has  since  been 
limited  to  the  i  jrves. 


STRUCTURE    OF   MUSCLE.  169 

longitudinal,  and  terminate  at  each  extremity  in  tendon,  the  entire  muscle 
being  fusiform  in  its  shape  ;  in  other  situations  they  are  disposed  like  the 
rays  of  a  fan,  converging  to  a  tendinous  point,  as  the  temporal,  pectoral, 
glutei,  &c.,  and  constitute  a  radiate  muscle.  Again,  they  are  penniform, 
converging  like  the  plumes  of  a  pen  to  one  side  of  a  tendon,  which  runs 
the  whole  length  of  the  muscle  as  in  the  peronei ;  or  bipenniform,  con- 
verging to  both  sides  of  the  tendon.  In  other  muscles  the  fibres  pass 
obliquely  from  the  surface  of  a  tendinous  expansion  spread  out  on  one 
side,  to  that  of  another  extended  on  the  opposite  side,  as  in  the  semi- 
membranosus ;  or,  they  are  composed  of  penniform  or  bipenniform  fasci- 
culi as  in  the  deltoid,  and  constitute  a  compound  muscle. 

The  nomenclature  of  the  muscles  is  defective  and  confused,  and  is 
generally  derived  from  some  prominent  character  which  each  muscle  pre- 
sents ;  thus,  some  are  named  from  their  situation,  as  the  tibialis,  peroneus; 
others  from  their  uses,  as  the  flexors,  extensors,  adductors,  abductors,  le- 
vators,  tensors,  &c.  Some  again  from  their  form,  as  the  trapezius,  trian- 
gularis,  deltoid,  &c. ;  and  others  from  their  direction,  as  the  rectus, 
obliquus,  transversalis,  &c.  Certain  muscles  have  received  names  ex- 
pressive of  their  attachments,  as  the  sterno-mastoid,  sterno-hyoid,  &c. ;  and 
others,  of  their  divisions,  as  the  biceps,  triceps,  digastricus,  complexus,  &c. 

In  the  description  of  a  muscle  we  express  its  attachment  by  the  w7ords 
"  origin"  and  "  insertion ;"  the  term  origin  is  generally  applied  to  the 
more  fixed  or  central  attachment,  or  to  the  point  towards  which  the  motion 
is  directed,  while  insertion  is  assigned  to  the  more  movable  point,  or  to 
that  most  distant  from  the  centre  ;  but  there  are  many  exception's  to  this 
principle,  and  as  many  muscles  pull  equally  by  both  extremities,  the  use 
of  such  terms  must  be  regarded  as  purely  arbitrary. 

In  structure,  muscle  is  composed  of  bundles  of  fibres  of  variable  size 
called  fasciculi,  which  are  enclosed  in  a  cellular  membranous  investment 
or  sheath,  and  the  latter  is  continuous  with  the  cellular  framework  of  the 
fibres.  Each  fasciculus  is  composed  of  a  number  of  smaller  bundles,  and 
these  of  single  fibres,  which,  from  their  minute  size  and  independent  ap- 
pearance, have  been  distinguished  by  the  name  of  ultimate  fibres.  The 
ultimate  Jib  re  is  found  by  microscopic  investigation  to  be  itself  a  fasciculus 
(ultimate  fasciculus),  made  up  of  a  number  of  ultimate  fibrils  enclosed  in 
a  delicate  sheath  or  myolemma.*  Two  kinds  of  ultimate  muscular  fibre 
exist  in  the  animal  economy ;  viz.,  that  of  voluntary  or  animal  life,  and 
that  of  involuntary  or  organic  life. 

The  ultimate  Jibre  of  animal  life  is  known  by  its  size,  by  its  uniformity 
of  calibre,  and  especially  by  the  very  beautiful  transverse  markings  which 
occur  at  short  and  regular  distances  throughout  its  whole  extent.  It  also 
presents  other  markings  or  stria?,  having  a  longitudinal  direction,  which 
indicate  the  existence  of  fibrilla?  within  its  myolemma.  The  myolemma, 
or  investing  sheath  of  the  ultimate  fibre,  is  thin,  structureless  and  trans- 
parent. 

*  In  the  summer  of  1836,  while  engaged  with  Dr.  Jones  Quain  in  the  examination  of 
the  animal  tissues  with  a  simple  dissecting  microscope,  constructed  by  Powell,  I  first 
saw  that  the  ultimate  fibre  of  muscle  was  invested  by  a  proper  sheath,  for  which  I  pro- 
posed the  term  "  Myolemma ;"  a  term  which  was  adopted  by  Dr.  Quain  in  the  fourth 
edition  of  his  "  Elements  of  Anatomy."  We  at  that  time  believed  that  the  transverse 
folding  of  that  sheath  gave  rise  to  the  appearance  of  transverse  striee,  an  opinion  whicv 
subsequent  examinations  proved  to  be  incorrect.  Mr.  Bowman  employs  the  term  "  Sar- 
colemma,"  as  synonymous  with  Myolemma. 

15 


170  STRUCTURE    OF    MUSCLE. 

According  to  Mr.  Bowman*  the  ultimate  fibres  are  polygonal  in  shape 
[fig.  100]  from  mutual  pressure.  They  are  also  variable  in  their  size,  not 
merely  in  different  classes  and  genera  of  animals  and  different  sexes,  but 
even  in  the  same  muscle.  For  example,  the  average  diameter  of  the  ulti- 
mate fibre  in  the  human  female  is  4-54-,  while  that  of  the  male  is  3^3,  the 
average  of  both  being  ?£3.  The  largest  fibres  are  met  with  in  fishes,  in 
which  animals  they  average  5^z  ;  the  next  largest  are  found  in  man,  while 
in  other  classes  they  range  in  the  following  order: — insects  4}^  ;  reptiles 
^4-;  mammalia  5^,-;  birds  5$7. 

The  ultimate  fibrils  of  animal  life,  according  to  Mr.  Bowman,  are  beaded 
filaments  consisting  of  a  regular  succession  of  segments  and  constrictions, 
the  latter  being  narrower  than  the  former,  and  the  component  substance 
probably  less  dense. 

Fig.  lOO.f  Fig.  1014 


An  ultimate  fibre  consists  of  a  bundle  of  these  fibrils,* which  are  so  dis- 
posed that  all  the  segments  and  all  the  constrictions  correspond,  and  in 
this  manner  give  rise  to  the  alternate  light  and  dark  lines  of  the  transverse 
striae.  The  fibrils  are  connected  together  with  very  different  degrees  of 
closeness  in  different  animals ;  in  man  they  are  but  slightly  adherent,  and 
distinct  longitudinal  lines  of  junction  may  be  observed  between  them ; 
they  also  separate  very  easily  when  macerated  for  some  time.  Besides 
the  more  usual  separation  of  the  ultimate  fibre  into  fibrils,  it  breaks  when 
stretched,  into  transverse  sections  [fig.  101,]  corresponding  with  the  dark 
line  of  the  stria?,  sw\  consequently  with  the  constrictions  of  the  fibrillse. 
When  this  division  occurs  with  the  greatest  facility,  the  longitudinal  lines 
are  indistinct,  or  scarcely  perceptible.  "  In  fact,"  says  Mr.  Bowman, 
"  the  primitive  fasciculus  seems  to  consist  of  primitive  component  segments 
or  particles,  arranged  so  as  to  form,  in  one  sense,  fibrillae,  and  in  another 
sense,  discs ;  and  which  of  these  two  may  happen  to  present  itself  to  the 
observer,  will  depend  on  the  amount  of  adhesion,  endways  or  sideways, 
existing  between  the  segments.  Generally,  in  a  recent  fas;  iculus,  there 
are  transverse  striae,  showing  divisions  into  discs,  and  longitudinal  striae, 
marking  its  composition  by  fibrillae." 

Mr.  Bowman  has  observed  that  in  the  substance  of  the  ultimate  fibre 
there  exist  minute  "  oval  or  circular  discs,  frequently  concave  on  one  or 

*  On  the  Minute  Structure  and  Movements  of  Voluntary  Muscle.  By  Wm.  Bowman, 
Esq.  From  the  Philosophical  Transactions  for  1840. 

f  Transverse  section  of  ultimate  fibres  of  the  biceps,  copied  from  the  illustrations  to 
Mr.  Bowman's  paper.  In  this  figure  the  polygonal  form  of  the  fibres  is  seen,  and  their 
composition  of  ultimate  fibrils. 

$  An  ultimate  fibre,  in  which  the  transverse  splitting  into  discs,  in  the  direction  of  the 
constrictions  of  the  ultimate  fibrils  is  seen.  From  Mr.  Bowman's  paper. 


STRUCTURE    OF    MUSCLE. 


171 


Fig.  102.* 


Fig.  103.t 


—  2 

'B 


I    8 


both  surfaces,  and  containing,  somewhere  near  the  centre,  one,  two,  or 
Jiree  minute  dots  or  granules."  Occasionally  they  are  seen  to  present  ir- 
regularities of  form,  which  Mr.  Bowman  is  inclined  to  regard  as  accidental. 
They  are  situated  between,  and  are  connected  with  the  fibrils,  and  are 
distributed  in  pretty  equal  numbers  through  the  fibre.  These  corpuscles 
are  the  nuclei  of  the  nucleated  cells  from  which  the 
muscular  fibre  was  originally  developed.  From  ob- 
serving, however,  that  their  "  absolute  number  is  far 
greater  in  the  adult  than  in  the  fetus,  while  their 
number,  relatively  to  the  bulk  of  the  fasciculi,  at  these 
two  epochs,  remains  nearly  the  same,"  Mr.  Bowman 
regards  it  as  certain,  that  "  during  development,  and 
subsequently,  a  further  and  successive  deposit  of  cor- 
puscles" takes  place.  The  corpuscles  are  brought 
into  view  only  when  the  muscular  fibre  is  acted  upon 
by  a  solution  of  "  one  of  the  milder  acids,  as  the  citric." 
According  to  my  own  investigations,!  the  ultimate 
fibril  of  animal  life  is  cylindrical  when  isolated,  and 
probably  polygonal  from  pressure  when  forming  part 
of  an  ultimate  fibre  or  fasciculus.  It  measures  in 
diameter  ^tW  °f  an  inch,  and  is  composed  of  a  suc- 
cession of  cells  connected  by  their  flat  surfaces.  The 
cells  are  filled  with  a  transparent  substance,  which  I 
have  termed  myoline.  The  myoline  differs  in  density 
in  different  cells,  and  from  this  circumstance  bestows 
a  peculiarity  of  character  on  certain  of  the  cells ;  for 
example,  when  a  fibril  in  its  passive  state  is  examined, 
there  will  be  seen  a  series  of  dark  oblong  bodies  se- 
parated by  light  spaces  of  equal  length ;  now  the  dark 
bodies  are  each  composed  of  a  pair  of  cells  contain- 
ing the  densest  form  of  myoline,  and  are  hence  highly  refractive  while  the 
transparent  spaces  are  constituted  by  a  pair  of  cells  containing  a  more 
fluid  myoline.  When  the  fibrils  are  collected  together  so  as  to  form  an 
ultimate  fibre  or  fasciculus,  the  appearance  of  the  cell  is  altered ;  those 
which  look  dark  in  the  single  fibril,  that  is,  the  most  refractive,  being 

*  Mass  of  ultimate  fibres  from  the  pectoralis  major  of  the  human  fcetus,  at  nine 
months.  These  fibres  have  been  immersed  in  a  solution  of  tartaric  acid,  and  their 
'numerous  corpuscles,  turned  in  various  directions,  some  presenting  nucleoli,"  are 
shown.  From  Mr.  Bowman's  paper. 

j-  These  were  made  on  dissections  of  fresh  human  muscle,  prepared  with  great  care 
by  Mr.  Lealand,  partner  of  the  eminent  optician,  Mr.  Powell. 

t  Structure  of  the  ultimate  muscular  fibril  and  fibre  of  animal  life. 

A.  An  ultimate  muscular  fibril  in  the  state  of  partial  contraction. 

B.  A  similar  fibril  in  the  state  of  ordinary  relaxation.     This  fibril  measured  j^g^ 
of  an  inch  in  diameter. 

c.  A  similar  fibril  put  upon  the  stretch,  and  measuring  sa' aT  of  an  inch  in  diameter. 

n.  Plan  of  a  portion  of  an  ultimate  fibre,  showing  the  manner  in  which  the  transverse 
strife  are  produced  by  the  collocation  of  the  fibrils. 

Nos.  1,  1.  The  pair  of  highly-refractive  cells;  they  form  the  dark  parts  of  the  single 
fibrils,  but  the  bright  parts  of  the  fibre  D.  In  the  stretched  fibril  c,  each  cell  has  the 
appearance  of  being  double.  2,  2.  The  pair  of  less  refractive  cells,  light  in  the  single 
fibrils,  but  forming  the  shaded  stria  in  D.  The  transverse  septum  between  these  cells 
is  very  conspicuous ;  and  in  c  two  other  septa  are  seen  to  exist,  making  the  number  of 
transparent  cells  four.  In  D,  the  tier  of  cells  immediately  above  the  c^ark  tier  is  partiady 
illumined  from  the  obliquity  of  the  light. 


in 


J72 


STRUCTURE   OF   MUSCLE. 


Fig.  104.* 


ranged  side  by  side,  constitute  the  bright  band ;  while  the  transparent 
cells  of  the  single  fibril  are  the  shaded  stria  of  the  fibre. 

When  the  ultimate  fibril  is  very  much  stretched,  the  two  highly-refrac- 
tive cells  appear  each  to  be  double,  while  the  transparent  space  is  evidently 
composed  of  four  cells. 

The  ultimate  fibre  of  organic  life  (Fig.  104,  4,  5)  is  a  simple  homoge- 
neous filament,  much  smaller  than  the  fibre  of  animal  life,  flat,  and  with- 
out transverse  markings.  Besides  these  characters,  there  may  generally 
be  seen  a  dark  line  or  several  dark  points  in  its  interior,  and  not  unfre- 
quently  the  entire  fibre  appears  enlarged  at  irregular  distances.  These 
appearances  are  due  to  the  presence  of  the  unobliterated  nuclei  of  cells 
from  which  the  fibre  was  originally  developed.  The  fibres  of  organic  life 
are  collected  into  fasciculi  of  various  size,  and  are  held  together  by  dark 
nuclear  fibres,  similar  to  those  which  bind  the  fasciculi  of  fibrous  tissue 
(p.  134.) 

The  development  of  muscular  fibre  is 
effected  by  means  of  the  formation  of 
nucleated  cells  out  of  an  original  blas- 
tema, and  the  conversion  of  those  cells, 
by  a  process  already  described  (p.  46), 
into  the  tubuli  of  ultimate  fibres,  while 
their  contents,  by  a  subsequent  deve- 
lopmental action,  are  transferred  into 
ultimate  fibrils.  According  to  this  view 
the  cell  membranes  constitute  the  myo- 
lemma,  and  the  contents  of  the  cell  are 
a  blastema  out  of  which  new  cells  are 
formed. 

The  disposition  of  these  latter  cells,  in  the  production  of  fibrilke,  is 
probably  much  more  simple  than  has  hitherto  been  conceived.  In  the 
muscular  fibre  of  organic  life,  the  process  would  seem  to  stop  short  of  the 
formation  of  fibrillae,  the  cells  being  accumulated  without  apparent  order. 
The  corpuscles,  observed  by  Mr.  Bowman,  in  foetal  muscle  (fig.  102),  and 
the  nodosities  of  organic  fibre,  are  obviously  undeveloped  cells  and  nuclei. 
Muscles  are  divided  into  two  great  classes,  voluntary  and  involuntary, 
to  which  may  be  added,  as  an  intermediate  and  connecting  link,  the 
muscle  of  the  vascular  system,  the  heart. 

The  voluntary,  or  system  of  animal  life,  is  developed  from  the  external 
or  serous  layer  of  the  germinal  membrane,  and  comprehends  the  whole 
of  the  muscles  of  the  limbs  and  of  the  trunk.  The  involuntary,  or  organic 
system,  is  developed  from  the  internal  or  mucous  layer,  and  constitutes 
the  thin  muscular  structure  of  the  intestinal  canal,  bladder,  and  internal 

*  1.  A  muscular  fibre  of  animal  life  enclosed  in  its  myolemma;  the  transverse  and 
longitudinal  striae  are  seen. 

2.  An  ultimate  fibril  of  muscular  fibre  of  animal  life,  according  to  Mr.  Bowman. 

3  A  muscular  fibre  of  animal  life,  similar  to  1,  but  more  highly  magnified.  Its  myo- 
lemma is  so  thin  and  transparent,  as  to  permit  the  ultimate  fibrils  to  be  seen  through 
The  true  nature  of  the  longitudinal  striae  is  seen  in  this  fibre,  as  well  as  the  mode  of 
formation  of  the  transverse  striae. 

4.  A  muscuiar  fibre  of  organic  life,  from  the  urinary  bladder,  magnified  600  times, 
linear  measure.     Two  of  the  nuclei  are  seen. 

5.  A  muscular  fibre  of  organic  life,  from  the  stomach,  magnified  600  times.     The 
diameter  of  this  and  of  the   preceding  fibre,  midway  between  the   nuclei,  was 

of  an  inch. 


MUSCLES  OF  THE  HEAD  AND  NECK.  173 

organs  of  generation.  At  the  commencement  of  the  alimentary  canal  in 
the  oesophagus,  and  near  its  termination  in  the  rectum,  the  muscular  coat 
is  formed  by  a  blending  of  the  fibres  of  both  classes.  The  heart  is  deve- 
loped from  the  middle,  or  vascular  layer  of  the  germinal  membrane ;  and 
although  involuntary  in  its  action,  is  composed  of  ultimate  fibres,  having 
the  transverse  striae  of  the  muscle  of  animal  life. 

The  muscles  may  be  arranged  in  conformity  with  the  general  division 
of  the  body  into,  —  1.  Those  of  the  head  and  neck.  2.  Those  of  the 
trunk.  3.  Those  of  the  upper  extremity.  4.  Those  of  the  lower  ex- 
tremity. 

MUSCLES  OF  THE  HEAD  AND  NECK. 

The  muscles  of  the  head  and  neck  admit  of  a  subdivision  into  those  of 
the  head  and  face,  and  those  of  the  neck. 

Muscles  of  the  Head  and  Face.  —  These  muscles  may  be  divided  into 
groups,  corresponding  with  the  natural  regions  of  the  head  and  face ;  the 
groups  are  eight  in  number,  viz. — 

1.  Cranial  group.  5.  Superior  labial  group. 

2.  Orbital  group.  6.  Inferior  labial  group. 

3.  Ocular  group.  7.  Maxillary  group. 

4.  Nasal  group.  8.  Auricular  group. 

The  muscles  of  each  of  these  groups  may  be  thus  arranged — 

1.  Cranial  group.  Levator  labii  superioris  proprius, 
Occipito-frontalis.                                 Levator  anguli  oris, 

Zygomaticus  major, 

2.  Orbital  group.  Zygomaticus  minor, 
Orbicularis  palpebrarum,  Depressor  labii  superioris  aleeque 
Corrugator  supercilii,  nasi. 

Tensor  tarsi. 

6.  Inferior  labial  group. 

3.  Ocular  group.  .„  ,  .     ,    .       .  ,  # 

(Orbicularis  oris), 

Levator  palpebrse,  Depressor  labii  inferioris, 

Rectus  superior,  Depressor  anguli  oris, 

Rectus  inferior,  Levator  labii  inferioris. 
Rectus  internus, 

Rectus  externus,  7.  Maxillary  group. 

Obliquus  superior,  Masseter, 

Obliquus  inferior.  Temporal, 

4.  Nasal  group.  Buccinator, 
Pyramidalis  nasi,  Pterygoideus  externus, 
Compressor  nasi,  Pterygoideus  internus. 
Dilatator  naris.  a  Auricular  group. 

5.  Superior  labial  group.  Attollens  aurem, 
(Orbicularis  oris),  Attrahens  aurem, 
Levator  labii  superioris  alsque  nasi,     Retrahens  aurem. 

*  The  Orbicularis  oris,  from  encircling  the  mouth,  belongs  necessarily  to  both  the 
superior  and  inferior  labial  regions;  it  is  therefore  enclosed  within  parentheses  in 
both. 

]5* 


174 


CRANIAL    GROUP. 


1.   Cranial  group. — Occipito-frontalis. 

Dissection.  —  The  occipito-frontalis  is  to  be  dissected  by  making  a  Ion 

gitudinal  incision  along  the  vertex  of  the 
Fig.  105.»  head,  from  the  tubercle  on  the  occipital 

bone  to  the  root  of  the  nose ;  and  a 
second  incision  along  the  forehead  and 
around  the  side  of  the  head,  to  join  the 
two  extremities  of  the  preceding.  Dis- 
sect the  integument  and  superficial  fascia 
carefully  outwards,  beginning  at  the  an- 
terior angle  of  the  flap,  where  the  mus- 
cular fibres  are  thickest,  and  remove  it 
altogether.  This  dissection  requires  care ; 
for  the  muscle  is  very  thin,  and,  without 
attention,  would  be  raised  with  the  in- 
tegument. There  is  no  deep  fascia  on 
the  face  and  head,  nor  is  it  required  ;  for 
here  the  muscles  are  closely  applied 
against  the  bones  upon  which  they  de- 
pend for  support,  whilst  in  the  extremities 
the  support  is  derived  from  the  dense 
layer, of  fascia  by  which  they  are  invested,  and  which  forms  for  each  a 
distinct  sheath. 

The  OCCIPITO-FRONTALIS  is  a  broad  musculo-aponeurotic  layer,  which 
covers  the  whole  of  the  side  of  the  vertex  of  the  skull,  from  the  occiput  to 
the  eyebrow.  It  arises  by  tendinous  fibres  from  the  outer  two-thirds  of 
the  superior  curved  line  of  the  occipital,  and  from  the  mastoid  portion  of 
the  temporal  bone.  Its  insertion  takes  place  by  means  of  the  blending  of 
the  fibres  of  its  anterior  portion  with  those  of  the  orbicularis  palpebrarum, 
corrugator  supercilii,  levator  labii  superioris  alceque  nasi,  and  pyramidalis 
nasi.  The  muscle  is  fleshy  in  front  over  the  frontal  bone  and  behind  over 
the  occipital,  the  two  portions  being  connected  by  a  broad  aponeurosis. 
The  two  muscles,  together  with  their  aponeurosis,  cover  the  whole  of  the 
vertex  of  the  skull,  hence  their  designation  galea  capitis  ;  they  are  loosely 
adherent  to  the  pericranium,  but  very  closely  to  the  integument,  particu- 
larly over  the  forehead. 

Relations.  —  This  muscle  is  in  relation  by  its  external  surface  from- be- 
fore backwards,  with  the  frontal  and  supra-orbital  vessels,  the  supra-orbital 
and  facial  nerve,  the  temporal  vessels  and  nerve,  the  occipital  vessels  an'd 

*  The  muscles  of  the  head  and  face.  1.  The  frontal  portion  of  the  occipito-frontalis. 
2.  Its  occipital  portion.  3.  Its  aponeurosis.  4.  The  orbicularis  palpebramm,  which 
conceals  the  corrugator  supercilii  and  tensor  tarsi.  5.  The  pyramidalis  nasi.  6.  The 
compressor  nasi.  7.  The  orbicularis  oris.  8.  The  levator  labii  superioris  alreque  nasi , 
the  adjoining  fasciculus  between  numbers  8  and  9  is  the  labial  portion  of  the  muscle 
9.  The  levator  labii  superioris  proprius;  the  lower  part  of  the  levator  anguli  oris  is  seen 
between  the  muscles  10  and  11.  10.  The  zygomaticus  minor.  11.  The  zygomaticus 
major.  12.  The  depressor  labii  inferioris.  13.  The  depressor  anguli  oris.  14.  The 
levatur  labii  inferioris.  15.  The  superficial  portion  of  the  masseter.  16.  Its  deep  por- 
tion. 17.  The  attrahens  aurem.  18.  The  buccinator.  19.  The  attollens  aurem.  20. 
The,  temporal  fascia  which  covers  in  the  temporal  muscle.  21.  The  retrahens  aurem 
22.  The  anterior  belly  of  the  digastricus  muscle ;  the  tendon  is  seen  passing  through 
its  aponeurotic  pulley.  23.  The  stylo-hyoid  muscle,  pierced  by  the  posterior  belly  of  the 
digastricus.  24.  The  mylo-hyoideus  muscle.  25.  The  upper  part  of  the  sterno-mastoid, 
{•C.  The  upper  part  of  the  trapezius.  The  muscle  between  25  and  26  is  the  splenius 


ORBITAL    GROUP.  175 

nerves,  and  with  the  integument,  to  which  it  is  very  closely  adherent.  Its 
under  surface  is  attached  to  the  pericranium  by  a  loose  areolar  tissue 
which  admits  of  considerable  movement. 

Actions.  —  To  raise  the  eyebrows,  thereby  throwing  the  integument  of 
the  forehead  into  transverse  wrinkles.  Some  persons  have  the  power  of 
moving  the  entire  scalp  upon  the  pericranium  by  means  of  these  muscles. 

2.    Orbital  group. — Orbicularis  palpebrarum, 
Corrugator  supercilii, 
Tensor  tarsi. 

Dissection.  —  The  dissection  of  the  face  is  to  be  effected  by  continuing 
the  longitudinal  incision  of  the  vertex  of  the  previous  dissection  onwards 
to  the  tip  of  the  nose,  and  thence  downwards  to  the  margin  of  the  upper 
lip ;  then  carry  an  incision  along  the  margin  of  the  lip  to  the  angle  of  the 
mouth,  and  transversely  across  the  face  to  the  angle  of  the  lower  jaw. 
Lastly,  divide  the  integument  in  front  of  the  external  ear  upwards  to  the 
transverse  incision  which  was  made  for  exposing  the  occipito-frontalis. 
Dissect  the  integument  and  superficial  fascia  carefully  from  the  whole  of 
the  region  included  by  these  incisions,  and  the  present  with  the  two  fol- 
lowing groups  of  muscles  will  be  brought  into  viewr. 

The  ORBICULARIS  PALPEBRARUM  is  a  sphincter  muscle,  surrounding  the 
orbit  and  eyelids.  It  arises  from  the  internal  angular  process  of  the  frontal 
bone,  from  the  nasal  process  of  the  superior  maxillary,  and  from  a  short 
tendon  (tendo  oculi)  which  extends  between  the  nasal  process  of  the  supe- 
rior maxillary  bone,  and  the  inner  extremities  of  the  tarsal  cartilages  of  the 
eyelids.  The  fibres  encircle  the  orbit  and  eyelids,  forming  a  broad  and 
thin  muscular  plane,  which  is  inserted  into  the  lower  border  of  the  tendo 
oculi,  and  into  the  nasal  process  of  the  superior  maxillary  bone.  Upon 
the  eyelids  the  fibres  are  thin  and  pale,  and  possess  an  involuntary  action. 
The  tendo  oculi,  in  addition  to  its  insertion  into  the  nasal  process  of  the 
superior  maxillary  bone,  sends  a  process  inwards  which  expands  over  the 
.achrymal  sac,  and  is  attached  to  the  ridge  of  the  lachrymal  bone :  this  is 
the  reflected  aponeurosis  of  the  tendo  oculi. 

Relations. — By  its  superficial  surface  it  is  closely  adherent  to  the  integu- 
ment from  which  it  is  separated  over  the  eyelids  by  a  loose  areolar  tissue. 
By  its  deep  surface  it  lies  in  contact  above  with  the  upper  border  of  the 
orbit,  wTith  the  corrugator  supercilii  muscle,  and  with  the  frontal  and 
supra-orbital  vessels  and  supra-orbital  nerve ;  below,  with  the  lachrymal 
sac,  with  the  origins  of  the  levator  labii  superioris  alseque  nasi,  levator 
labii  superioris  proprius,  zygomaticus  major  and  minor  muscles,  and 
malar  bone  ;  and  externally  with  the  temporal  fascia.  Upon  the  eyelids 
it  is  in  relation  with  the  broad  tarsal  ligament  and  tarsal  cartilages,  and 
by  its  upper  border  gives  attachment  to  the  occipito-frontalis  muscle. 

The  CORRUGATOR  SUPERCILII  is  a  small  narrow  and  pointed  muscle, 
situated  immediately  above  the  orbit  and  beneath  the  upper  segment  of 
the  orbicularis  palpebrarum  muscle.  It  arises  from  the  inner  extremity 
of  the  superciliary  ridge,  and  is  inserted  into  the  under  surface  of  the  orbi- 
cularis palpebrarum  at  a  point  corresponding  with  the  middle  of  the  super- 
ciliary arch. 

Relations. — By  its  superficial  surface  with  the  pyramidalis  nasi,  occipito 
frontalis  and  orbicularis  palpebrarum  muscle ;   and  by  its  deep  surface* 
with  the  supra-orbital  vessels  and  nerve. 


176 


OCULAR    GROUP. 


Fig.  lOG.f 


The  TENSOR  TARSI  (Homer's*  muscle)  is  a  thin  plane  of  musculai 
fibres,  about  three  lines  in  breadth  and  six  in  length.     It  is  best  dissected 

by  separating  the  eyelids  from  the  eye, 
and  turning  them  over  the  nose  without 
disturbing  the  tendo  oculi ;  then  dissect 
away  the  small  fold  of  mucous  membrane 
called  plica  semilunaris,  and  some  loose 
cellular  tissue  under  which  the  muscle  is 
concealed.  It  arises  from  the  orbital  sur- 
face of  the  lachrymal  bone,  and  passing 
across  the  lachrymal  sac  divides  into  two 
slips,  which  are  inserted  into  the  lachry- 
mal canals  as  far  as  the  puncta. 
Jlctions. — The  palpebral  portion  of  the  orbicularis  acts  involuntarily 
in  closing  the  lids,  and  from  the  greater  curve  of  the  upper  lid,  upon  that 
principally.  The  entire  muscle  acts  as  a  sphincter,  drawing  at  the  same 
time,  by  means  of  its  osseous  attachment,  the  integument  and  lids  inwards 
towards  the  nose.  The  corrugatores  superciliorum  draw  the  eyebrows 
downwards  and  inwards,  and  produce  the  vertical  wrinkles  of  the  fore- 
head. The  tensor  tarsi,  or  lachrymal  muscle,  draws  the  extremities  of 
the  lachrymal  canals  inwards,  so  as  to  place  the  puncta  in  the  best  posi- 
tion for  receiving  the  tears.  It  serves  also  to  keep  the  lids  in  relation 
with  the  surface  of  the  eye,  and  compresses  the  lachrymal  sac.  Dr.  Hor- 
ner  is  acquainted  with  two  persons,  who  have  the  voluntary  power  of 
drawing  the  lids  inwards  by  these  muscles  so  as  to  bury  the  puncta  in  the 
angle  of  the  eye. 

3.    Ocular  group. — Levator  palpebra, 
Rectus  superior, 
Rectus  inferior, 
Rectus  intern  us, 
Rectus  externus, 
Obliquus  superior, 
Obliquus  inferior. 


Fig.  1074 


Dissection. — To  open  the  orbit  (the 
calvarium  and  brain  having  been  re- 
moved) the  frontal  bone  must  be  sawn 
through  at  the  inner  extremity  of  the 
orbital  ridge,  and,  externally,  at  its 
outer  extremity.  The  roof  of  the  or- 
bit may  then  be  comminuted  by  a  few 
light- blows  with  the  hammer;  a  pro- 
cess easily  accomplished,  on  account 
of  the  thinness  of  the  orbital  plate  of 
the  frontal  bone  and  lesser  wing  of  the 

*  W.  E.  Homer,  M.  D.,  Professor  of  Anatomy  in  the  University  of  Pennsylvania.  The 
notice  of  this  muscle  is  contained  in  a  work  published  in  Philadelphia  in  1827,  entitled 
"  Lessons  in  Practical  Anatomy." 

f  A  view  of  the  tensor  tarsi  muscle.  1,  1.  Bony  margins  of  the  orbit.  2.  Opening 
between  the  eyelids.  3.  Internal  face  of  the  orbit.  4.  Origin  of  the  tensor  tarsi.  5,  5. 
Insertion  into  the  neighbourhood  of  the  puncta  lachrymalis. 

t  The  muscles  of  the  eyeball ;  the  view  is  taken  from  the  outer  side  of  the  right  orbit. 
2.  A  small  fragment  of  the  sphenoid  bone  around  the  entrance  of  the  optic  nerve  into 
til"  orbit.  2.  The  optic  nerve.  3.  The  globe  of  the  eye.  4.  The  levator  palpcbrte 


RECTUS  EXTERNUS.  177 

sphenoid.  The  superciliary  portion  of  the  orbit  may  now  be  driven  for- 
wards by  a  smart  blow,  and  the  external  angular  process  and  external 
wall  of  the  orbit  outwards  in  the  same  manner ;  the  broken  fragments  of 
the  roof  of  the  orbit  should  then  be  removed.  By  this  means  the  perios- 
teum will  be  exposed  unbroken  and  undisturbed.  Remove  the  periosteum 
from  the  whole  of  the  upper  surface  of  the  exposed  orbitj  and  examine  the 
narts  beneath. 

The  LEVATOR  PALPEBR^:  is  a  long,  thin,  and  triangular  muscle  ;  situated 
in  the  upper  part  of  the  orbit  on  the  middle  line ;  it  arises  from  the  upper 
margin  of  the  optic  foramen,  and  from  the  fibrous  sheath  of  the  optic  nerve, 
and  is  inserted  into  the  upper  border  of  the  superior  tarsal  cartilage. 

Relations. — By  its  upper  surface  with  the  fourth  nerve,  the  supra-orbital 
nerve  and  artery,  the  periosteum  of  the  orbit,  and  in  front  with  the  inner 
surface  of  the  broad  tarsal  ligament.  By  its  under  surface  it  rests  upon 
the  superior  rectus  muscle,  and  the  globe  of  the  eye ;  it  receives  its  nerve 
and  artery  by  this  aspect,  and  in  front  is  covered  for  a  short  distance  by 
the  conjunctiva. 

The  RECTUS  SUPERIOR  (attollens)  arises  from  the  upper  margin  of  the 
optic  foramen,  and  from  the  fibrous  sheath  of  the  optic  nerve,  and  is  in- 
serted into  the  upper  surface  of  the  globe  of  the  eye  at  a  point  somewhat 
more  than  three  lines  from  the  margin  of  the  cornea. 

Relations. — By  its  upper  surface  with  the  levator  palpebrse  muscle ;  by 
the  under  surface  with  the  optic  nerve,  the  ophthalmic  artery  and  nasal 
nerve,  from  which  it  is  separated  by  a  layer  of  fascia  and  by  the  adipose 
tissue  of  the  orbit,  and  in  front  with  the  globe  of  the  eye,  the  tendon  of  the 
superior  oblique  muscle  being  interposed. 

The  RECTUS  INFERIOR  (depressor)  arises  from  the  inferior  margin  of  the 
optic  foramen  by  a  tendon  (ligament  of  Zinn)  which  is  common  to  it,  the 
internal  and  the  external  rectus,  and  from  the  fibrous  sheath  of  the  optic 
nerve ;  it  is  inserted  into  the  inferior  surface  of  the  globe  of  the  eye  at  a 
Jittle  more  than  two  lines  from  the  margin  of  the  cornea. 

Relations. — By  its  upper  surface  with  the  optic  nerve,  the  inferior  oblique 
branch  of  the  third  nerve,  the  adipose  tissue  of  the  orbit,  and  the  under 
surface  of  the  globe  of  the  eye.  By  its  under  surface  with  the  periosteum 
of  the  floor  of  the  orbit,  and  with  the  inferior  oblique  muscle. 

The  RECTUS  INTERNUS  (adductor),  the  thickest  and  shortest  of  the 
straight  muscles,  arises  from  the  common  tendon,  and  from  the  fibrous 
sheath  of  the  optic  nerve ;  and  is  inserted  into  the  inner  surface-  of  the 
globe  of  the  eye  at  two  lines  from  the  margin  of  the  cornea. 

Relations. — By  its  internal  surface  with  the  optic  nerve,  the  adipose 
tissue  of  the  orbit  and  the  eyeball.  By  its  outer  surface  with  the  perios- 
teum of  the  orbit ;  and  by  its  upper  border  with  the  anterior  and  posterior 
ethmoidal  vessels,  the  nasal  and  supra-trochlear  nerve. 

The  RECTUS  EXTERNUS  (abductor),  the  longest  of  the  straight  muscles, 
arises  by  two  distinct  heads,  one  from  the  common  tendon,  the  other  with 

muscle.  5.  The  superior  oblique  muscle.  6.  Its  cartilaginous  pulley.  7.  Its  reflected 
tendon.  8.  The  inferior  oblique  muscle;  the  small  square  knob  at  its  commencement 
is  a  piece  of  its  bony  origin  broken  off.  9.  The  superior  rectus.  10.  The  internal  rectua 
almost  concealed  by  the  optic  nerve.  11.  Part  of  the  external  rectus,  showing  its  two 
heads  of  origin.  12.  The  extremity  of  the  external  rectus  at  its  insertion;  the  inter 
mediate  portion  of  the  muscle  having  been  removed.  13.  The  inferior  rectus.  14 
The  tunica  albuginea,  formed  by  the  expansion  of  the  tendons  of  the  four  recti. 

M 


178  OBLIQUUS    INFERIOR. 

the  origin  of  the  superior  rectus  from  the  margin  of  the  optic  foramen ; 
the  nasal,  third  and  sixth  nerves  passing  between  its  heads.  It  is  inserted 
into  the  outer  surface  of  the  globe  of  the  eye  at  a  little  more  than  two  lines 
from  the  margin  of  the  cornea. 

Relations. — By  its  internal  surface  with  the  third,  the  nasal,  the  sixth, 
and  the  optic  nerve,  the  ciliary  ganglion  and  nerves,  the  ophthalmic  artery 
and  vein,  the  adipose  tissue  of  the  orbit,  the  inferior  oblique  muscle  and 
the  eyeball.  By  its  external  surface  with  the  periosteum  of  the  orbit ;  and 
by  the  upper  border  with  the  lachrymal  vessels  and  nerve  and  the  lachry- 
mal gland. 

The  recti  muscles  present  several  characters  which  are  common  to  all ; 
thus  they  are  thin,  have  each  the  form  of  an  isosceles  triangle,  bear  the 
same  relation  to  the  globe  of  the  eye,  and  are  inserted  in  a  similar  manner 
into  the  sclerotica,  at  about  two  lines  from  the  circumference  of  the  cornea. 
The  points  of  difference  relate  to  thickness  and  length ;  the  internal  rectus 
is  the  thickest  and  shortest,  the  external  rectus  the  longest  of  the  four,  and 
the  superior  rectus  the  most  thin.  The  insertion  of  the  four  recti  muscles 
into  the  globe  of  the  eye  forms  a  tendinous  expansion,  which  is  continued 
as  far  as  the  margin  of  the  cornea,  and  is  called  the  tunica  albuginea. 

The  OBLIQUUS  SUPERIOR  (trochlearis)  is  a  fusiform  muscle  arising  from 
the  margin  of  the  optic  foramen,  and  from  the  fibrous  sheath  of  the  optic 
nerve  ;  it  passes  forwards  to  the  pulley  beneath  the  internal  angular  pro- 
cess of  the  frontal  bone ;  its  tendon  is  then  reflected  beneath  the  superior 
rectus  muscle,  to  the  outer  and  posterior  part  of  the  globe  of  the  eye, 
where  it  is  inserted  into  the  sclerotic  coat,  near  the  entrance  of  the  optic 
nerve.  The  tendon  is  surrounded  by  a  synovial  membrane,  while  passing 
through  the  cartilaginous  pulley. 

Relations.  —  By  its  superior  surface  with  the  fourth  nerve,  the  supra- 
trochlear  nerve,  and  with  the  periosteum  of  the  orbit.  By  the  inferior 
surface  with  the  adipose  tissue  of  the  orbit,  the  upper  border  of  the  inter- 
nal rectus  and  the  vessels  and  nerves  in  relation  with  that  border. 

The  OBLIQUUS  INFERIOR,  a  thin  and  narrow  muscle,  arises  from  the 
inner  margin  of  the  superior  maxillary  bone,  immediately  external  to  the 
lachrymal  groove,  and  passes  beneath  the  inferior  rectus,  to  be  inserted 
into  the  outer  and  posterior  part  of  the  eyeball,  at  about  two  lines  from 
the  entrance  of  the  optic  nerve. 

Relations.  —  By  its  superior  surface  with  the  inferior  rectus  muscle  and 
with  the  eyeball ;  and  by  the  inferior  surface  with  the  periosteum  of  the 
floor  of  the  orbit,  and  the  external  rectus  muscle. 

According  to  Mr.  Farrall*  the  muscles  of  the  orbit  are  separated  from 
the  globe  of  the  eyeball  and  from  the  structures  immediately  surrounding 
the  optic  nerve,  by  a  distinct  fascia,  which  is  continuous  with  the  broad 
tarsal  ligament  and  with  the  tarsal  cartilages.  This  fascia  the  author  terms 
the  tunica  vaginalis  oculi^  it  is  pierced  anteriorly  for  the  passage  of  the 
six  orbital  muscles,  by  six  openings  through  which  the  tendons  of  the 
muscles  play  as  through  pulleys.  The  use  assigned  to  it  by  Mr.  Farrall 
is  to  protect  the  eyeball  from  the  pressure  of  its  muscles  during  their  ac- 
tion. By  means  of  this  structure  the  recti  muscles  are  enabled  to  impress 

*  In  a  paper  read  before  the  Royal  Society,  on  the  10th  of  June,  1841. 
t  Tliis  fascia  was  first  described  by  Mr.  Dalrymple  in  his  work  on  the  "Anatomy  ol 
the  Human  Eye."   1834. 


NASAL    GROUP.  179 

,1  rotatory  movement  upon  the  eyeball ;  and  in  animals  provided  with  a 
retractor  muscle,  they  also  act  as  antagonists  to  its  action. 

Actions. — The  levator  palpebrae  raises  the  upper  eyelid.  The  four  recti, 
acting  singly,  pull  the  eyeball  in  the  four  directions  ;  upwards,  downwards, 
inwards,  and  outwards.  Acting  by  pairs,  they  carry  the  eyeball  in  the 
diagonal  of  these  directions,  viz.  upwards  and  inwards,  upwards  and  out- 
wards, downwards  and  inwards,  or  downwrards  and  outwards.  Acting  all 
together,  they  directly  retract  the  globe  within  the  orbit.  The  superior 
oblique  muscle,  acting  alone,  rolls  the  globe  inwards  and  forwards,  and 
carries  the  pupil  outwards  and  downwards  to  the  lower  and  outer  angle 
of  the  orbit.  The  inferior  oblique,  acting  alone,  rolls  the  globe  outwards 
and  backwards,  and  carries  the  pupil  outwards  and  upwards  to  the  upper 
and  outer  angle  of  the  eye.  Both  muscles  acting  together,  draw  the  eye- 
ball forwards,  and  give  the  pupil  that  slight  degree  of  eversion  which  en- 
ables it  to  admit  the  largest  field  of  vision. 

4.  Nasal  Group. — Pyramidalis  nasi, 
Compressor  nasi, 
Dilatator  naris. 

The  PYRAMIDALIS  NASI  is  a  small  pyramidal  slip  of  muscular  fibres  sent 
downwards  upon  the  bridge  of  the  nose  by  the  occipito-frontalis.  It  is 
inserted  into  the  tendinous  expansion  of  the  compressores  nasi. 

Relations. — By  its  upper  surface  with  the  integument ;  by  its  under  sur- 
face with  the  periosteum  of  the  frontal  and  nasal  bone.  Its  outer  border 
corresponds  with  the  edge  of  the  orbicularis  palpebrarum,  and  its  inner 
border  with  its  fellow,  from  which  it  is  separated  by  a  slight  interval. 

The  COMPRESSOR  NASI  is  a  thin  and  triangular  muscle  ;  it  arises  by  its 
apex  from  the  canine  fossa  of  the  superior  maxillary  bone,  and  spreads  out 
upon  the  side  of  the  nose  into  a  thin  tendinous  expansion,  which  is  con- 
tinuous across  its  ridge  with  the  muscle  of  the  opposite  side. 

Relations.  —  By  its  superficial  surface  with  the  levator  labii  superioris 
proprius,  the  levator  labii  superioris  alaeque  nasi,  and  the  integument ;  by 
its  deep  surface  with  the  superior  maxillary  and  nasal  bone,  and  with  the 
alar  and  lateral  cartilages  of  the  nose. 

The  DILATATOR  NARIS  is  a  thin  and  indistinct  muscular  apparatus  ex- 
panded upon  the  ala  of  the  nostril,  and  consisting  of  an  anterior  and  a 
posterior  slip.  The  anterior  slip  (levator  proprius  ala?  nasi  anterior)  ex- 
tends between  the  lateral  and  alar  cartilage  at  about  midway  between  the 
tip  and  the  attached  margin  of  the  nose.  The  posterior  slip  (levator  pro- 
prius alse  nasi  posterior)  is  attached  above  to  the  margin  of  the  nasal  pro- 
cess of  the  superior  maxillary  bone,  and  below  to  the  small  cartilages  of 
the  ala  nasi.  These  muscles  are  difficult  of  dissection  from  the  close 
adherence  of  the  integument  to  the  nasal  cartilages. 

Actions.  —  The  pyramidalis  nasi,  as  a  point  of  attachment  of  the  occi- 
pito-frontalis, assists  that  muscle  in  its  action :  it  also  draws  down  the 
inner  angle  of  the  eyebrow,  and  by  its  insertion  fixes  the  aponeurosis  of 
the  compressores  nasi.  The  compressores  nasi  appear  to  act  in  expanding 
rather  than  in  compressing  the  nares ;  hence  probably  the  compressed 
state  of  the  nares  from  paralysis  of  these  muscles  in  the  last  moments  of^ 
life,  or  in  compression  of  the  brain.     The  use  of  the  dilatator  naris  is  ex 
pressed  in  its  name. 


130  SUPERIOR   LABIAL    GROUP. 

5.  Superior  Labial  Group. — Orbicularis  oris, 

Levator  labii  superioris  alseque  nasi, 

Levator  labii  superioris  proprius, 

Levator  anguli  oris, 

Zygomaticus  major, 

Zygomaticus  minor, 

Depressor  labii  superioris  alseque  nasi. 

The  ORBICULARIS  ORIS  is  a  sphincter  muscle,  completely  surrounding 
the  mouth,  and  possessing  consequently  neither  origin  nor  insertion.  It 
is  composed  of  two  thick  semicircular  planes  of  fibres,  which  embrace  the 
rima  of  the  mouth,  and  interlace  at  their  extremities,  where  they  are  con- 
tinuous with  the  fibres  of  the  buccinator,  and  of  the  other  muscles  con- 
nected with  the  angle  of  the  mouth.  The  upper  segment  is  attached  by 
means  of  a  small  muscular  fasciculus  (naso-labialis)  to  the  columna  of  the 
nose ;  and  other  fasciculi  connected  with  both  segments  and  attached  to 
the  maxillary  bones  are  termed  "  accessorii." 

Relations. — By  its  superficial  surface  with  the  integument  of  the  lips, 
with  which  it  is  closely  connected.  By  its  deep  surface  with  the  mucous 
membrane  of  the  mouth,  the  labial  glands  and  coronary  arteries  being 
interposed.  By  its  circumference  with  the  numerous  muscles  which  move 
the  lips,  and  by  the  inner  border  with  the  mucous  membrane  of  the  rima 
of  the  mouth. 

The  LEVATOR  LABII  SUPERIORIS  AL^QUE  NASI  is  a  thin  triangular 
muscle :  it  arises  from  the  upper  part  of  the  nasal  process  of  the  superior 
maxillary  bone ;  and  becoming  broader  as  it  descends,  is  inserted  by  two 
distinct  portions  into  the  ala  of  the  nose  and  upper  lip. 

Relations. — By  its  superficial  surface  with  part  of  the  orbicularis  palpe- 
brarum  muscle,  the  facial  artery,  and  the  integument.  By  its  deep  surface 
with  the  superior  maxillary  bone,  compressor  nasi,  alar  cartilage,  and 
with  a  muscular  fasciculus  attached  only  to  the  bone,  and  thence  called 
musculus  anomalus. 

The  LEVATOR  LABII  SUPERIORIS  PROPRIUS  }$  a  thin  quadrilateral  mus- 
cle :  it  arises  from  the  lower  border  of  the  orbit,  and  passing  obliquely 
downwards  and  inwards,  is  inserted  into  the  integument  of  the  upper  lip ; 
its  deep  fibres  being  blended  with  those  of  the  orbicularis. 

Relations. — By  its  superficial  surface  with  the  lower  segment  of  the 
orbicularis  palpebrarum,  with  the  facial  artery,  and  with  the  integument. 
By  its  deep  surface  with  the  origins  of  the  compressor  nasi  and  levator 
anguli  oris  muscle,  and  with  the  infra-orbital  artery  and  nerve. 

The  LEVATOR  ANGULI  ORIS  arises  from  the  canine  fossa  of  the  superior 
maxillary  bone,  and  passes  outwards  to  be  inserted  into  the  angle  of  the 
mouth,  intermingling  its  fibres  with  those  of  the  orbicularis,  zygomatici, 
and  depressor  anguli  oris. 

Relations. — By  its  superficial  surface  with  the  levator  labii  superioris 
proprius,  the  branches  of  the  infra-orbital  artery  and  nerve,  and  inferiorly 
with  the  integument.  By  its  deep  surface  with  the  superior  maxillary  bone 
and  buccinator  muscle. 

The  ZYGOMATIC  muscles  are  two  slender  fasciculi  of  fibres  which  arise 
from  the  malar  bone,  and  are  inserted  into  the  angle  of  the  mouth,  where 
they  are  continuous  with  the  other  muscles  attached  to  this  part.  The 
zy^omaticus  minor  is  situated  in  front  of  the  major,  and  is  continuous  at 


INFERIOR    LABIAL    GROUP.  181 

its  insertion  with  the  levator  labii  superioris  proprius ;  it  is  not  unfre- 
quently  wanting. 

Relations. — The  zygomaticus  major  muscle  is  in  relation  by  its  superficial 
surface  with  the  lower  segment  of  the  orbicularis  palpebrarum  above,  and 
the  fat  of  the  cheek  and  integument  for  the  rest  of  its  extent.  By  its  deep 
surface  with  the  malar  bone,  the  masseter,  and  buccinator  muscle,  and 
the  facial  vessels.  The  zygomaticus  minor,  being  in  front  of  the  major, 
has  no  relation  with  the  masseter  musck,  while  inferiorly  it  rests  upon  the 
evator  anguli  oris. 

The  DEPRESSOR  LABII  SUPERIORIS  AL^IQUE  NASI  (myrtiformis)  is  seen 
by  drawing  upwards  the  upper  lip,  and  raising  the  mucous  membrane. 
It  is  a  small  oval  slip  of  muscle,  situated  on  each  side  of  the  fraenum, 
arising  from  the  incisive  fossa,  and  passing  upwards  to  be  inserted  into 
the  upper  lip  and  into  the  ala  and  columna  of  the  nose.  This  muscle  is 
continuous  by  its  outer  border  with  the  edge  of  the  compressor  nasi. 

Relations. — By  its  superficial  surface  with  the  mucous  membrane  of  the 
mouth,  the  orbicularis  oris  and  levator  labii  superioris  alseque  nasi  muscle ; 
and  by  its  deep  surface  with  the  superior  maxillary  bone. 

Actions. — The  orbicularis  oris  produces  the  direct  closure  of  the  lips 
by  means  of  its  continuity  at  the  angles  of  the  mouth  with  the  fibres  of  the 
buccinator.  When  acting  singly  in  the  forcible  closure  of  the  mouth,  the 
integument  is  thrown  into  wrinkles  in  consequence  of  its  firm  connexion 
with  the  surface  of  the  muscle.  The  levator  labii  superioris  alseque  nasi 
lifts  the  upper  lip  with  the  ala  of  the  nose,  and  expands  the  opening  of  the 
nares.  The  depressor  labii  superioris  alseque  nasi  is  the  antagonist  to  this 
muscle,  drawing  the  upper  lip  and  ala  of  the  nose  downwards,  and  con- 
tracting the  opening  of  the  nares.  The  levator  labii  superioris  proprius 
is  the  proper  elevator  of  the  upper  lip ;  acting  singly  it  draws  the  lip  a 
little  to  one  side.  The  levator  anguli  oris  lifts  the  angle  of  the  mouth  and 
draws  it  inwards,  while  the  zygomatic  pull  it  upwards  and  outwards,  as 
in  laughing. 

6.  Inferior  Labial  Group. — Depressor  labii  inferioris, 

Depressor  anguli  oris, 
Levator  labii  inferioris. 

Dissection. — To  dissect  the  inferior  labial  region  continue  the  vertical 
section  from  the  margin  of  the  lower  lip  to  the  point  of  the  chin.  Then 
carry  an  incision  along  the  margin  of  the  lower  jaw  to  its  angle.  Dissect 
off  the  integument  and  superficial  fascia  from  the  whole  of  this  surface, 
and  the  muscles  of  the  inferior  labial  region  will  be  exposed. 

The  DEPRESSOR  LABII  INFERIORIS  (quadratus  menti)  arises  from  the 
oblique  line  by  the  side  of  the  symphysis  of  the  lower  jaw,  and  passing 
upwards  and  inwards  is  inserted  into  the  orbicularis  muscle  and  integu- 
ment of  the  lower  lip. 

Relations. — By  its  superficial  surface  with  the  platysma  myoides,  part 
of  the  depressor  anguli  oris,  and  with  the  integument  of  the  chin,  with 
which  it  is  closely  connected.  By  the  deep  surface  with  the  levator  labii 
inferioris,  the  labial  glands  and  mucous  membrane  of  the  lower  lip.  and 
with  the  mental  nerve  and  artery. 

The  DEPRESSOR  ANGULI  ORIS  (triangularis  oris)  is  a  triangular  p*ane  of 
muscle  arising  by  a  broad  base  from  the  external  oblique  ridge  of  the 
16 


182  MAXILLARY    GROUP. 

lower  jaw,  and  inserted  by  its  apex  into  the  angle  of  the  mouth,  where  it 
is  continuous  with  the  levator  anguli  oris  and  zygomaticus  major. 

Relations. — By  its  superficial  surface  with  the  integument ;  and  by  its 
deep  surface  with  the  depressor  labii  inferioris,  the  buccinator,  and  tne 
branches  of  the  mental  nerve  and  artery. 

The  LEVATOR  LABII  INFERIORIS  (levator  menti)  is  a  small  conical  slip 
of  muscle  arising  from  the  incisive  fossa  of  the  lower  jaw,  and  inserted 
into  the  integument  of  the  chin.  It  is  in  relation  with  the  mucous  mem- 
brane of  the  mouth,  with  its  fellow,  and  with  the  depressor  labii  inferioris. 

Actions.  —  The  depressor  labii  inferioris  draws  the  lower  lip  directly 
downwards,  and  at  the  same  time  a  little  outwards.  The  depressor  an- 
guli oris,  from  the  radiate  direction  of  its  fibres,  will  pull  the  angle  of  the 
mouth  either  downwards  and  inwards,  or  downwards  and  outwards,  and 
be  expressive  of  grief;  or  acting  with  the  levator  anguli  oris  and  zygo- 
maticus major,  it  will  draw  the  angle  of  the  mouth  directly  backwards. 
The  levator  labii  inferioris  raises  and  protrudes  the  integument  of  the 
chin. 

7.  Maxillary  group. — Masseter, 

Temporalis, 
Buccinator, 
Pterygoideus  externus, 
Pterygdideus  internus. 

Dissection. — The  masseter  has  been  already  exposed  by  the  preceding 
dissection. 

The  MASSETER  (fAarftfaofjuxi,  to  chew,)  is  a  short,  thick,  and  sometimes 
quadrilateral  muscle,  composed  of  two  planes  of  fibres,  superficial  and 
deep.  The  superficial  layer  arises  by  a  strong  aponeurosis  from  the 
tuberosity  of  the  superior  maxillary  bone,  the  lower  border  of  the  malar 
bone  and  zygoma,  and  passes  backwards  to  be  inserted  into  the  ramus 
and  angle  of  the  inferior  maxilla.  The  deep  layer  arises  from  the  poste- 
rior part  of  the  zygoma,  and  passes  forwards,  to  be  inserted  into  the 
upper  half  of  the  ramus.  This  muscle  is  tendinous  and  muscular  in  its 
structure. 

Relations.  —  By  its  external  surface  with  the  zygomaticus  major  and 
risorius  Santorini  muscle,  the  parotid  gland  and  Stenon's  duct,  the  trans- 
verse facial  artery,  the  pes  anserinus  and  the  integument.  By  its  internal 
surface  with  the  temporal  muscle,  the  buccinator,  from  which  it  is  separated 
by  a  mass  of  fat,  and  with  the  ramus  of  the  lower  jaw.  By  its  posterior 
border  with  the  parotid  gland ;  and  by  the  anterior  border  with  the  facial 
artery  and  vein. 

Dissection.  —  Make  an  incision  along  the  upper  border  of  the  zygoma, 
for  the  purpose  of  separating  the  temporal  fascia  from  its  attachment.  Then 
saw  through  the  zygomatic  process  of  the  malar  bone,  and  through  the 
root  of  the  zygoma,  near  to  the  meatus  auditorius.  Draw  down  the 
zygoma,  and  with  it  the  origin  of  the  masseter,  and  dissect  the  latter 
muscle  away  from  the  ramus  and  angle  of  the  inferior  maxilla.  Now  re- 
move the  temporal  fascia  from  the  rest  of  its  attachment,  and  the  whole  of 
the  temporal  muscle  will  be  exposed. 

The  TEMPORAL  is  a  broad  and  radiating  muscle  occupying  a  considera- 
ole  extent  of  the  side  of  the  head  and  filling  the  temporal  fossa.  It  is 
covered  in  by  a  very  dense  fascia  (temporal  fascia)  which  is  attached  along 


BUCCINATOR PTERYGOIDEI.  133 

the  temporal  ridge  on  the  side  of  the  skull,  extending  from  the  external 
angular  process  of  the  frontal  bone  to  the  mastoid  portion  of  the  temporal ; 
inferiorly,  it  is  connected  to  the  upper  border  of  the  zygoma.  The  muscle 
arises  by  tendinous  fibres  from  the  whole  length  of  the  temporal  rido-e, 
and  by  muscular  fibres  from  the  temporal  fascia  and  entire  surface  of  the 
temporal  fossa.  Its  fibres  converge  to  a  strong  and  narrow  tendon,  which 
is  inserted  into  the  apex  of  the  coronoid  process,  and  for  some  way  down 
upon  its  inner  surface. 

Relations.  —  By  its  external  surface  with  the  temporal  fascia,  which  se- 
parates it  from  the  attollens  and  attrahens  aurem  muscle,  the  temporal 
vessels  and  nerves ;  and  with  the  zygoma  and  masseter.  By  its  internal 
surface  with  the  bones  forming  the  temporal  fossa,  the  external  pterygoid 
muscle,  a  part  of  the  buccinator,  and  the  internal  maxillary  artery  with  its 
deep  temporal  branches. 

By  sawing  through  the  coronoid  process  near  to  its  base,  and  pulling  it 
upwards,  together  with  the  temporal  muscle,  which  may  be  dissected  from 
the  fossa,  we  obtain  a  view  of  the  entire  extent  of  the  buccinator  and  of 
the  external  pterygoid  muscle. 

The  BUCCINATOR  (buccina,  a  trumpet),  the  trumpeter's  muscle,  arises 
from  the  alveolar  process  of  the  superior  maxillary  and  from  the  external 
oblique  line  of  the  inferior  maxillary  bone,  as  far  forward  as  the  second 
bicuspid  tooth,  and  from  the  pterygo-maxillary  ligament.  This  ligament 
is  the  raphe  of  union  between  the  buccinator  and  superior  constrictor 
muscle,  and  is  attached  by  one  extremity  to  the  hamular  process  of  the 
internal  pterygoid  plate,  and  by  the  other  to  the  extremity  of  the  molar 
ridge.  The  fibres  of  the  muscle  converge  towards  the  angle  of  the  mouth 
where  they  cross  each  other,  the  superior  being  continuous  with  the  infe- 
rior segment  of  the  orbicularis  oris,  and  the  inferior  with  the  superior 
segment.  The  muscle  is  invested  externally  by  a  thin  fascia. 

Relations. — By  its  external  surface,  posteriorly  with  a  large  and  rounded 
mass  of  fat,  which  separates  the  muscle  from  the  ramus  of  the  lower  jaw, 
the  temporal,  and  the  masseter ;  anteriorly  with  the  risorius  Santorini,  the 
zygomatici,  the  levator  anguli  oris,  and  the  depressor  anguli  oris.  It  is 
also  in  relation  with  a  part  of  Stenon's  duct,  wrhich  pierces  it  opposite  the 
second  molar  tooth  of  the  upper  jaw,  with  the  transverse  facial  artery,  the 
branches  of  the  facial  and  buccal  nerve,  and  the  facial  artery  and  vein. 
By  its  internal  surface  with  the  buccal  glands  and  mucous  membrane  of 
the  mouth. 

The  EXTERNAL  PTERYGOID  is  a  short  and  thick  muscle,  broader  at  its 
origin  than  at  its  insertion.  It  arises  by  two  heads,  one  from  the  pterygoid 
ridge  on  the  greater  ala  of  the  sphenoid ;  the  other  from  the  external 
pterygoid  plate  and  tuberosity  of  the  palate  bone.  The  fibres  pass  back- 
wards, to  be  inserted  into  the  neck  of  the  lower  jaw  and  the  interarticular 
fibro-cartilage.  The  internal  maxillary  artery  frequently  passes  between 
the  two  heads  of  this  muscle. 

Relations.  — By  its  external  surface,  with  the  ramus  of  the  lower  jaw, 
the  temporal  muscle,  and  the  internal  maxillary  artery ;  by  its  internal 
surface,  with  the  internal  pterygoid  muscle,  internal  lateral  ligament  of  the 
lower  jaw,  arteria  meningea  media,  and  inferior  maxillary  nerve  ;  and  by 
its  upper  border,  with  the  muscular  branches  of  the  inferior  maxillary 
nerve  ;  the  internal  maxillary  artery  passes  between  the  two  heads  of  this 
muscle,  an  J  its  lower  origin  is  pierced  by  the  buccal  nerve 


184  AURICULAR    GROUP. 

The  external  pterygoid  muscle  must  now  be  removed,  the  ramus  of  the 
lower  jaw  sawn  through  its  lower  third,  and  the  head  of  the  bone  dislo 
cated  from  its  socket  and  withdrawn,  for  the  purpose  of  seeing  the  ptery 
goideus  internus. 

The  INTERNAL  PTERYGOID  is  a  thick  quadrangular  muscle.  It  arises 
from  the  pterygoid  fossa,  and  descends  obliquely  backwards,  to  be  in- 
serted into  the  ramus  and  angle  of  the  lower  jaw :  it  resembles  the  masse- 
ter  in  appearance  and  direction,  and  was  named  by  Winslow  the  internal 
masseter. 

Relations. — By  its  external  surface,  with  the  external  pterygoid,  the  in- 
ferior maxillary  nerve  and  its  branches,  the  internal  maxillary  artery  and 
branches,  the  internal  lateral  ligament,  and  the  ramus  of  the  lower  jaw 
By  its  internal  surface,  with  the  tensor  palati,  superior  constrictor  ana 
fascia  of  the  pharynx ;  and  by  its  posterior  border,  with  the  parotid  gland. 

Actions. — The  maxillary  muscles  are  the 
Fig.  108*  active  agents  in  mastication,  and  form  an  ap- 

paratus beautifully  fitted  for  that  office.  The 
buccinator  circumscribes  the  cavity  of  the 
mouth,  and  with  the  aid  of  the  tongue,  keeps 
the  fooci  un(ler  the  immediate  pressure  of  the 
teeth.  By  means  of  its  connexion  with  the 
superior  constrictor,  it  shortens  the  cavity  of 
the  pharynx  from  before  backwards,  and  be- 
comes an  important  auxiliary  in  deglutition. 
The  temporal,  the  masseter,  and  the  internal 
pterygoid,  are  the  bruising  muscles,  drawing 
the  lower  jaw  against  the  upper  with  great 
force.  The  two  latter,  by  the  obliquity  of  their  direction,  assist  the  ex- 
ternal pterygoid  in  grinding  the  food,  by  canying  the  lower  jaw  forward 
upon  the  upper ;  the  jaw  being  brought  back  again  by  the  deep  portion 
of  the  masseter  and  posterior  fibres  of  the  temporal.  The  whole  of  these 
muscles,  acting  in  succession,  produce  a  rotatory  movement  of  the  teeth 
upon  each  other,  which,  with  the  direct  action  of  the  lower  jaw  against 
the  upper,  effects  the  proper  mastication  of  the  food. 

8.  Auricular  Group. — Attollens  aurem, 
Attrahens  aurem, 
Retrahens  aurem. 

Dissection. — The  three  small  muscles  of  the  ear  may  be  exposed  by 
removing  a  square  of  integument  from  around  the  auricula.  This  opera- 
tion must  be  performed  with  care,  otherwise  the  muscles,  which  are  ex 
tremely  thin,  will  be  raised  with  the  superficial  fascia.  They  are  best 
dissected  by  commencing  with  their  tendons,  and  thence  proceeding  in 
the  course  of  their  radiating  fibres. 

The  ATTOLLENS  AUREM  (superior  auris),  the  largest  of  the  three,  is  a  thin 
triangular  plane  of  muscular  fibres  arising  from  the  edge  of  the  aponeurosis 
of  the  occipito-frontalis,  and  inserted  into  the  upper  part  of  the  concha. 

It  is  in  relation  by  its  external  surface  with  the  integument,  and  by  the 
internal  with  the  temporal  aponeurosis. 

*  The  two  pterygoid  muscles.  The  zygomatic  arch  and  the  greater  part  of  the  ramus 
<>f  the  lower  jaw  have  been  removed,  in  order  to  bring  these  muscles  into  view.  i. 
Ihe  spheroid  origin  of  the  external  pterygoid  muscle.  2.  Its  pterygoid  origin.  3.  The 
internal  pterygoiil  rnuscfe. 


MUSCLES    OF   THE   NECK.  185 

The  ATTRAHENS  AUREM  (anterior  auris),  also  triangular,  arises  from 
the  edge  of  the  aponeurosis  of  the  occipito-frontalis,  and  is  inserted  into 
the  anterior  part  of  the  helix,  covering  in  the  anterior  and  posterior  tem- 
poral arteries. 

It  is  in  relation  by  its  external  surface  with  the  integument ;  and  by  the 
internal  with  the  temporal  aponeurosis  and  with  the  temporal  artery  and 
veins. 

The  RETRAHENS  AUREM  (posterior  auris),  arises  by  three  or  four  mus- 
cular slips  from  the  mastoid  process.  They  are  inserted  into  the  posterior 
surface  of  the  concha. 

It  is  in  relation  by  its  external  surface  with  the  integument,  and  by  its 
internal  surface  with  the  mastoid  portion  of  the  temporal  bone. 

JJctions. — The  muscles  of  the  auricular  region  possess  but  little  action 
in  man ;  they  are  the  analogues  of  important  muscles  in  brutes.  Their 
use  is  sufficiently  explained  in  then:  names. 

MUSCLES     OF     THE     NECK. 

The  muscles  of  the  neck  may  be  arranged  into  eight  groups  correspond 
ing  with  the  natural  divisions  of  the  region  ;  they  are  the — 

1.  Superficial  group. 

2.  Depressors  of  the  os  hyoides  and  larynx. 

3.  Elevators  of  the  os  hyoides  and  larynx. 

4.  Lingual  group. 

5.  Pharyngeal  group. 

6.  Soft  palate  group. 

7.  Pra?vertebral  group. 

8.  Proper  muscles  of  the  larynx. 

And  each  of  these  groups  consist  of  the  following  muscles :—  viz. 

I 

1.  Superficial  Group.  Stylo-glossus, 
Platysma-myoides,                              Palato-glossus. 
Sterno-cleido-mastoideus. 

5.  Muscles  of  the  Pharynx. 

2.  Depressors  of  the  os  hyoides     Constrictor  inferior, 

and  larynx.  Constrictor  medius, 

Sterno-hyoideus,  Constrictor  superior, 

Sterno-thyroideus,  Stylo-pharyngeus, 

Thyro-hyoideus,  Palato-pharyngeus. 
Omo-hyoideus. 

6.  Muscles  of  the  soft  Palate. 

3.  Elevators  of  the  os  hyoides     Levator  palati, 

and  larynx.  Tensor  palati, 

Digastricus,  Azygos  uvulae, 

Stylo-hyoideus,  Palato-glossus, 

Mylo-hyoideus,  Palato-pharyngeus. 
Genio-hyoideus, 

Gemo-hyo-glossus.  7.  Prcevertebral  Group. 

Rectus  anticus  major, 

4.  Muscles  of  the  Tongue.  Rectus  anticus  minor, 
Genio-hyo-glossus,  Scalenus  anticus, 
Hyo-glossus,  Scalenus  posticus, 
Lingualis,  Longus  colli. 

16* 


186 


PLATYSMA    MYOIDES. 


8  Muscles  of  the  Larynx. 
Crico-thyroideus, 
Crico-arytcenoideus,  posticus, 


Crico-arytsenoideus,  lateralis, 

Thyro-arytaenoideus. 

Arytffinoideus. 


Dissection. — The  dissection  of  the  neck  should  be  commenced  by 
making  an  incision  along  the  middle  line  of  its  fore  part  from  the  chin  to 
the  sternum,  and  bounding  it  superiorly  and  inferiorly  by  two  transverse 
incisions ;  the  superior  one  being  carried  along  the  margin  of  the  lower 
jaw,  and  across  the  mastoid  process  to  the  tubercle  on  the  occipital  bone, 
the  inferior  one  along  the  clavicle  to  the  acromion  process.  The  square 
flap  of  integument  thus  included  should  be  turned  back  from  the  entire 
side  of  the  neck,  which  brings  into  view  the  superficial  fascia,  and  on  the 
removal  of  a  thin  layer  of  superficial  fascia  the  platysma  myoides  will  be 
exposed. 

The  PLATYSMA  MYOIDES  (*Xa<ru£,  pvs  £i<$o?,  broad  muscle-like  lamella), 
is  a  thin  plane  of  muscular  fibres,  situated  between  the  two  layers  of  the 
superficial  cervical  fascia ;  it  arises  from  the  integument  over  the  pectoralis 
major  and  deltoid  muscles,  and  passes  obliquely  upwards  and  inwards 
along  the  side  of  the  neck  to  be  inserted  into  the  side  of  the  chin,  oblique 
line  of  the  lower  jaw,  the  angle  of  the  mouth,  and  into  the  cellular  tissue 
of  the  face.  The  most  anterior  fibres  are  continuous  beneath  the  chin, 
with  the  muscle  of  the  opposite  side  ;  the  next  interlace  with  the  depressor 
anguli  oris,  and  depressor  labii  inferioris,  and  the  most  posterior  fibres  are 
disposed  in  a  transverse  direction  across  the  side  of  the  face,  arising  in  the 
cellular  tissue  covering  the  parotid  gland,  and  inserted  into  the  angle  of 
the  mouth,  constituting  the  risorius  Santorini.  The  entire  muscle  is  ana- 
logous to  the  cutaneous  muscle  of  brutes,  the  panniculus  carnosus. 

Relations. — By  its  external 
surface  with  the  integument, 
with  which  it  is  closely  adhe- 
rent below,  but  loosely  above. 
By  its  internal  surface,  below 
the  clavicle,  with  the  pectoralis 
major  and  deltoid ;  in  the  neck, 
with  the  external  jugular  vein 
and  deep  cervical  fascia;  on 
the  face,  with  the  parotid 
gland,  the  masseter,  the  facial 
artery  and  vein,  the  buccinator, 
the  depressor  anguli  oris,  and 
the  depressor  labii  inferioris. 

On  raising  the  platysma 
throughout  its  whole  extent, 
the  s^erno-mastoid  is  brought 
into  view. 

The  STERNO-CLEIDO-MASTOID 
is  the  large  oblique  muscle  of 

*The  muscles  of  the  anterior  aspect  of  the  neck  ;  on  the  left  side  the  superficial  mus- 
cles are  seen,  and  on  the  right  the  deep.  1.  The  posterior  belly  of  the  digastricus  mus- 
cle. 2.  Its  anterior  belly.  The  aponeurotic  pulley,  through  which  its  tendon  is  seen 
passing,  is  attached  to  the  body  of  the  os  hyoides.  3,  4.  The  stylo-hyoideus  muscle, 
transfixed  by  the  posterior  belly  of  the  digastricus.  5.  The  mylo-hyoideus.  6.  Tlia 


Fig.  109* 


DEPRESSORS  OP  THE  OS  HYOIDES  AND  LARYNX.     187 

the  nock,  and  is  situated  between  two  layers  of  the  deep  cervical  fascia 
It  arises,  as  implied  in  its  name,  from  the  sternum  and  clavicle  (xXst&ov), 
and  passes  obliquely  upwards  and  backwards  to  be  inserted  into  the  mas- 
toid  process  and  into  the  superior  curved  line  of  the  occipital  bone.  The 
sternal  portion  arises  by  a  rounded,  tendon,  increases  in  breadth  as  it 
ascends,  and  spreads  out  to  a  considerable  extent  at  its  insertion.  The 
clavicular  portion  is  broad  and  fleshy,  and  separate  from  the  sternal  portion 
below,  but  becomes  gradually  blended  with  its  posterior  surface  as  it 
ascends. 

Relations. — By  its  superficial  surface  with  the  integument,  the  platysma 
myoides,  the  external  jugular  vein,  superficial  branches  of  the  anterior 
cervical  plexus  of  nerves,  and  the  anterior  layer  of  the  deep  cervical  fascia. 
By  its  deep  surface  with  the  deep  layer  of  the  cervical  fascia;,  with  the 
sterno-clavicular  articulation,  the  sterno-hyoid,  sterno-thyroid,  omo-hyoid, 
sculeni,  levator  anguli  scapulae,  splenii,  and  the  posterior  belly  of  the  di- 
gastric muscle ;  with  the  phrenic  nerve,  and  the  posterior,  and  supra-sca- 
pular artery ;  with  the  deep  lymphatic  glands,  the  sheath  of  the  common 
carotid  and  internal  jugular  vein,  the  descendens  noni  nerve,  the  external 
carotid  artery  and  its  posterior  branches,  the  commencement  of  the  internal 
carotid  artery ;  with  the  cervical  plexus  of  nerves,  the  pneumogastric,  'the 
spinal  accessory,  the  hypoglossal,  the  sympathetic  and  the  facial  nerve, 
and  with  the  parotid  gland.  It  is  pierced  on  this  aspect  by  the  spinal  ac- 
cessory nerve  and  by  the  branches  of  the  mastoid  artery.  The  anterior 
border  of  the  muscle  is  the  posterior  boundary  of  the  great  anterior  triangle, 
the  other  two  boundaries  being  the  middle  line  of  the  neck  in  front,  and 
the  lower  border  of  the  jaw  above.  It  is  the  guide  to  the  operations  for 
the  ligature  of  the  common  carotid  artery  and  arteria  innominata,  and  for 
tesophagotomy.  The  posterior  border  is  the  anterior  boundary  of  the  great 
posterior  triangle  ;  the  other  two  boundaries  being  the  anterior  border  of 
the  trapezius  behind,  and  the  clavicle  below. 

Actions. — The  platysma  produces  a  muscular  traction  on  the  integu- 
ment of  the  neck,  which  prevents  it  from  falling  so  flaccid  in  old  persons 
as  would  be  the  case  if  the  extension  of  the  skin  were  the  mere  result  of 
elasticity.  It  draws  also  upon  the  angle  of  the  mouth,  and  is  one  of  the 
depressors  of  the  lower  jaw.  The  transverse  fibres  draw  the  angle  of  the 
mouth  outwards  and  slightly  upwards.  The  sterno-mastoid  muscles  are 
the  grea^anterior  muscles  of  connexion  between  the  thorax  and  the  head. 
Both  muscles  acting  together  bow  the  head  directly  forwards.  The  cla- 
vicular portions,  acting  more  forcibly  than  the  sternal,  give  stability  and 
steadiness  to  the  head  in  supporting  great  weights.  Either  muscle  acting 
singly  would  draw  the  head  towards  the  shoulder  of  the  same  side,  anu 
carry  the  face  towards  the  opposite  side. 

Second  Group. — Depressors  of  the  Os  Hyoides  and  Larynx. 
Sterno-hyoid,  Thyro-hyoid, 

Sterno-thyroid,  Omo-hyoid. 

genio-hyoideus.  7.  The  tongue.  8.  The  hyo-glossus.  9.  The  stylo-glossus.  10.  The 
stylo-pharyngeus.  11.  The  sterno-mastoid  muscle.  12.  Its  sternal  origin.  13.  Its  cla 
vicular  origin.  14.  The  sterno-hyoid.  15.  The  sterno-thyroid  of  the  right  side.  16. 
The  thyro-hyoid.  17.  The  hyoid  portion  of  the  omo-hyoid.  18,  18.  Its  scapular  portion, 
on  the  left  side,  the  tendon  of  the  muscle  is  seen  to  be  bound  down  by  a  portion  of  the 
deep  cervical  fascia.  19.  The  clavicular  portion  of  the  trapezius.  20.  The  scaU"iu* 
anticus  of  the  right  side.  21.  The  scalenus  posticus. 


188  DEPRESSORS    OF    THE    OS    HYOIDES    AND    LARYNX. 

Dissection. — These  muscles  are  brought  into  view  by  removing  the 
deep  fascia  from  off  the  front  of  the  neck  between  the  two  sterno-mastoid 
muscles.  The  omo-hyoid  to  be  seen  in  its  whole  extent  requires  that  the 
sterno-mastoid  muscle  should  be  divided  from  its  origin  and  turned  aside. 

The  STERNO-HYOIDEUS  is  a  narrow  riband-like  muscle,  arising  from  the 
posterior  surface  of  the  first  bone  of  the  sternum  and  inner  extremity  of 
the  clavicle.  It  is  inserted  into  the  lower  border  and  posterior  surface  of 
the  body  of  the  os  hyoides.  The  sterno-hyoidei  are  separated  by  a  con- 
siderable interval  at  the  root  of  the  neck,  but  approach  each  other  as  they 
ascend :  they  are  frequently  traversed  by  a  tendinous  intersection. 

Relations. — By  its  external  surface  with  the  deep  cervical  fascia,  the 
platysma  myoides  and  sterno-mastoid  muscle  ;  by  its  internal  surface  with 
the  sterno-thyroid,  and  thyro-hyoid  muscle,  and  the  superior  thyroid 
artery. 

The  STERNO-THYROIDEUS,  broader  than  the  preceding  beneath  which  it 
lies,  arises  from  the  posterior  surface  of  the  upper  bone  of  the  sternum, 
and  from  the  cartilage  of  the  first  rib  ;  it  is  inserted  into  the  oblique  line 
on  the  great  ala  of  the  thyroid  cartilage.  The  inner  borders  of  these 
muscles  lie  in  contact  along  the  middle  line,  and  they  are  generally  marked 
by  a  tendinous  intersection  at  their  lo\ver  part. 

Relations. — By  its  external  surface  with  the  sterno-hyoid,  omo-hyoid, 
and  sterno-mastoid  muscle  ;  by  its  internal  surface,  with  the  trachea  and 
inferior  thyroid  veins,  with  the  thyroid  gland,  the  lower  part  of  the  larynx, 
the  sheath  of  the  common  carotid  artery  and  internal  jugular  vein,  with 
the  subclavian  vein  and  vena  innominata,  and  on  the  right  side  with  the 
arteria  innominata.  The  middle  thyroid  vein  lies  along  its  inner  border. 

The  THYRO-HYOIDEUS  is  the  continuation  upwards  of  the  sterno-thyroid 
muscle.  It  arises  from  the  oblique  line  o.n  the  thyroid  cartilage,  and  is 
inserted  into  the  lower  border  of  the  body  and  great  cornu  of  the  os 
hyoides. 

Relations. — By  its  external  surface  with  the  sterno-hyoid  and  omo-hyoid 
muscle ;  by  its  internal  surface  with  the  great  ala  of  the  thyroid  cartilage, 
the  thyro-hyoidean  membrane,  and  the  superior  laryngeal  artery  and 
nerve. 

The  OMO-HYOIDEUS  (wfxor,  shoulder)  is  a  double-bellied  muscle  passing 
obliquely  across  the  neck  from  the  scapula  to  the  os  hyoides :  it  forms  an 
obtuse  angle  behind  the  sterno-mastoid  muscle,  and  is  retained  in  that 
position  by  means  of  a  process  of  the  deep  cervical  fascia  which  is  con- 
nected to  the  inner  border  of  its  tendon.  It  arises  from  the  upper  border 
of  the  scapula,  and  from  the  transverse  ligament  of  the  supra-scapular 
notch,  and  is  inserted  into  the  lower  border  of  the  body  of  the  os  hyoides. 

Relations. — By  its  superficial  surface  with  the  trapezius,  the  subclavius 
and  clavicle,  the  deep  cervical  fascia  and  platysma  myoides,  the  sterno- 
mastoid,  and  the  integument.  By  its  deep  surface  \vith  the  brachial  plexus, 
the  scaleni  muscles,  the  phrenic  nerve,  the  sheath  of  the  common  carotid 
artery  and  jugular  vein,  the  descendens  noni  nerve,  the  sterno-thyroid, 
and  thyro-hyoid  muscle,  and  the  sterno-hyoid  at  its  insertion.  The  sca- 
pular portion  of  the  muscle  divides  the  great  posterior  triangle  into  a  su- 
perior or  occipital  triangle  ;  and  an  inferior  or  subclavian  triangle,  which 
contains  the  subclavian  artery  and  brachial  plexus  of  nerves ;  the  other 
two  boundaries  of  the  latter  being  the  sterno-rnastoid  in  tront  and  the  cla- 
vicle below.  The  hyoid  portion  of  the  muscle  divides  the  great  anterior 


ELEVATORS    OF    THE    OS    HYOIDES.  189 

triangle  into  an  inferior  carotid  triangle  situated  below  the  muscle,  and 
into  a  superior  triangle  which  lies  above  the  muscle  and  is  again  subdi- 
vided by  the  digastricus  into  the  submaxillary  triangle  and  the  superior 
carotid  triangle.  The  other  two  boundaries  of  the  inferior  carotid  triangle, 
are  the  middle  line  of  the  neck  in  front  and  the  anterior  border  of  the 
sterno-mastoid  behind.  The  other  boundaries  of  the  superior  carotid  tri- 
angle are  the  posterior  belly  of  the  digastricus  muscle  above  and  the  an- 
terior border  of  the  sterno-mastoid  behind. 

Actions. — The  four  muscles  of  this  group  are  the  depressors  of  the  os 
hyoides  and  larynx.  The  three  former  drawing  these  parts  downwards 
in  the  middle  line,  and  the  two  omo-hyoidei  regulating  their  traction  to 
the  one  or  other  side  of  the  neck,  according  to  the  position  of  the  head. 
The  omo-hyoid  muscles  by  means  of  their  connexion  with  the  cervical 
fascia  are  rendered  tensors  of  that  portion  of  the  deep  cervical  fascia  which 
covers  in  the  lower  part  of  the  neck,  between  the  two  sterno-mastoid 
muscles. 

Third  Group. — Elevators  of  the  Os  Hyoides. 

Digastricus,  Genio-hyoid, 

Stylo-hyoid,  Genio-hyo-glossus. 

Mylo-hyoid, 

Dissection.  —  These  are  best  dissected  by  placing  a  high  block  beneath 
the  neck,  and  throwing  the  head  backwards.  The  integument  has  been 
already  dissected  away,  and  the  removal  of  the  cellular  tissue  and  fat 
brings  them  clearly  into  view. 

The  DIGASTRICUS  (<5/g,  twice,  yaov^,  belly)  is  a  small  muscle  situated 
immediately  beneath  the  side  of  the  body  of  the  lower  jaw ;  it  is  fleshy  at 
each  extremity,  and  tendinous  in  the  middle.  It  arises  from  the  digastric 
fossa,  upon  the  inner  side  of  the  mastoid  process  of  the  temporal  bone, 
and  is  inserted  into  a  depression  on  the  inner  side  of  the  lower  jaw,  close 
to  the  symphysis.  The  middle  tendon  is  held  in  connexion  with  the  body 
of  the  os  hyoides  by  an  aponeurotic  loop,  through  which  it  plays  as  through 
a  pulley;  the  loop  being  lubricated  by  a  synovial  membrane.  A  thin 
layer  of  aponeurosis  is  given  off  from  the  tendon  of  the  digastricus  at  each 
side,  which  is  connected  with  the  body  of  the  os  hyoides,  and  forms  a 
strong  plane  of  fascia  between  the  anterior  portions  of  the  two  muscles. 
This  fascia  is  called  the  supra-hyoidean. 

Relations.  —  By  its  superficial  surface  with  the  platysma  myoides,  the 
sterno-mastoid,  the  anterior  fasciculus  of  the  stylo-hyoid  muscle,  the 
parotid  gland,  and  submaxillary  gland.  By  its  deep  surface  with  the 
styloid  muscles,  the  hyo-glossus,  the  mylo-hyoid  muscle,  the  external 
carotid  artery,  the  lingual  and  the  facial  arteries,  the  internal  carotid  artery, 
the  jugular  vein,  and  the  hypoglossal  nerve.  The  digastric  muscle  forms 
the  two  inferior  boundaries  of  the  submaxillary  triangle,  the  superior  boun- 
dary being  the  side  of  the  body  of  the  lower  jaw.  In  the  posterior  half 
of  the  submaxillary  triangle  are  situated  the  submaxillary  gland  and  the 
facial  artery. 

The  STYLO-HYOIDEUS  is  a  small  and  slender  muscle  situated  in  imme- 
diate relation  with  the  posterior  belly  of  the  digastricus  muscle,  being 
pierced  by  its  tendon.  It  arises  from  the  middle  of  the  styloid  process, 
and  is  inserted  into  the  body  of  the  os  hyoides  near  the  middle  line. 


190  MYLO-HYOIDEUS — GENIO-HYOIDEUS. 

Relations.  —  By  its  superficial  surface  with  the  posterior  belly  of  the 
digastricus,  the  parotid  gland  and  submaxillary  gland ;  its  deep  relations 
are  similar  to  those  of  the  posterior  belly  of  the  digastricus. 

The  digastricus  and  stylo-hyoideus  must  be  removed  from  their  con- 
nexion with  the  lower  jaw  and  os  hyoides,  and  turned  aside  in  order  to 
see  the  next  muscle. 

The  MYLO-HYOIDEUS  (fxuXrj,  mola,  i.  e.  attached  to  the  molar  ridge  of 
the  lower  jaw)  is  a  broad  triangular  plane  of  muscular  fibres,  forming, 
with  its  fellow  of  the  opposite  side,  the  inferior  wall  or  floor  of  the  mouth, 
It  arises  from  the  molar  ridge  on  the  lower  jaw,  and  proceeds  obliquely 
inwards  to  be  inserted  into  the  raphe  of  the  two  muscles  and  into  the 
body  of  the  os  hyoides ;  the  raphe  is  sometimes  deficient  at  its  anterior 
part. 

Relations.  —  By  its  superficial,  or  inferior  surface,  with  the  platysma 
myoides,  the  digastricus,  the  supra-hyoidean  fascia,  the  submaxillary  gland 
and  the  submental  artery.  By  its  deep  or  superior  surface,  wdth  the  genio- 
hyoideus,  the  genio-hyo-glossus,  the  stylo-glossus,  the  gustatory  nerve,  the 
hypoglossal  nerve,  Wharton's  duct,  the  sublingual  gland,  and  the  mucous 
membrane  of  the  floor  of  the  mouth. 

After  the  mylo-hyoideus  has  been  examined,  it  should  be  cut  a\vay  from 
its  origin  and  insertion,  and  completely  removed.  The  view  of  the  next 
muscles  would  also  be  greatly  improved  by  dividing  the  lower  jaw  on  the 
near  side  of  the  symphysis,  and  drawing  it  outwards,  or  by  removing  it 
altogether,  if  the  ramus  have  been  already  cut  across  in  dissecting  the  in- 
ternal pterygoid  muscle.  The  tongue  may  then  be  drawn  out  of  the  mouth 
by  means  of  a  hook. 

The  GENIO-HYOIDEUS  (ysvsov,  the  chin)  arises  from  a  small  tubercle  upon 
the  inner  side  of  the  symphysis  of  the  lower  jaw,  and  is  inserted  into  the 
upper  part  of  the  body  of  the  os  hyoides.  It  is  a  short  and  slender  muscle, 
very  closely  connected  with  the  border  of  the  following. 

Relations. — By  its  superficial  or  inferior  surface,  with  the  mylo-hyoideus , 
by  the  deep  or  superior  surface,  with  the  lower  border  of  the  genio-hyo- 
glossus. 

The  GENIO-HYO-GLOSSUS  (yXcjcro'a,  the  tongue)  is  a  triangular  muscle, 
narrow  and  pointed  at  its  origin  from  the  lower  jaw,  broad  and  fan-shaped 
at  its  attachment  to  the  tongue.  It  arises  from  a  tubercle  immediately 
above  that  of  the  genio-hyoideus,  and  spreads  out  to  be  inserted  into  the 
whole  length  of  the  tongue,  from  its  base  to  the  apex,  and  into  the  body 
of  the  os  hyoides. 

Relations.  —  By  its  inner  surface  with  its  fellow  of  the  opposite  side. 
By  its  outer  surface  with  the  mylo-hyoideus,  the  hyo-glossus,  the  stylo* 
glossus,  lingualis,  the  sublingual  gland,  the  lingual  artery,  and  the  hypo- 
glossal  nerve.  By  its  upper  border  with  the  mucous  membrane  of  the  floor 
of  the  mouth,  in  the  situation  of  the  franum  lingua? ;  and  by  the  lower 
border  with  the  genio-hyoideus. 

Actions. — The  whole  of  this  group  of  muscles  acts  upon  the  os  hyoides 
when  the  lower  jaw  is  closed,  and  upon  the  lower  jaw  wrhen  the  os  hyoides 
is  drawn  downwards,  and  fixed  by  the  depressors  of  the  os  hyoides  and 
larynx.  The  genio-hyo-glossus  is,  moreover,  a  muscle  of  the  tongue  ;  its 
action  upon  that  organ  shall  be  considered  with  the  next  group. 


MUSCLES  OF  THE  TONGUE.  191 

Fourth  Group. — Muscles  of  the  Tongue. 

Genio-hyo-glossus,  Stylo-glossus, 

Hyo-glossus,  Palato-glossus. 

Lingualis, 

These  are  already  exposed  by  the  preparation  we  have  just  made  ;  there 
remains,  therefore,  only  to  dissect  and  examine  them. 

The  Genio-hyo-glossus,  the  first  of  these  muscles,  has  been  described 
with  the  last  group. 

The  HYO-GLOSSUS  is  a  square-shaped  plane  of  muscle,  arising  from  the 
whole  length  of  the  great  cornu  and  from  the  body  of  the  os  hyoides,  and 
inserted  between  the  stylo-glossus  and  lingualis  into  the  side  of  the  tongue. 
The  direction  of  the  fibres  of  that  portion  of  the  muscle  which  arises  from 
the  body  is  obliquely  backwards  ;  and  that  from  the  great  cornu  obliquely 
forwards ;  hence  they  are  described  by  Albinus  as  two  distinct  muscles, 
under  the  names  of  the  basio-glossus,  and  cerato-glossus,  to  which  he 
added  a  third  fasciculus,  arising  from  the  lesser  cornu,  and  spreading 
along  the  side  of  the  tongue,  the  chondro-glossus.  The  basio-glossus 
slightly  overlaps  the  cerato-glossus  at  its  upper  part,  and  is  separated  from 
it  by  the  transverse  portion  of  the  stylo-glossus. 

Relations. — By  its  external  surface  Fig>  no.* 

with  the  digastric  muscle,  the  stylo- 
hyoideus,  stylo-glossus,  and  mylo- 
hyoideus,  with  the  gustatory  nerve,  the 
hypoglossal  nerve,  Wharton's  duct  and 
the  sublingual  gland.  By  its  internal 
surface  with  the  middle  constrictor  of 
the  pharynx,  the  lingualis,  the  genio- 
hyo-glossus,  the  lingual  artery,  and 
the  glosso-pharyngeal  nerve. 

The  LINGUALIS. — The  fibres  of  this 
muscle  may  be  seen  towards  the  apex 
of  the  tongue,  issuing  from  the  interval 
between  the  hyo-glossus  and  genio- 
hyo-glossus ;  it  is  best  examined  by 
removing  the  preceding  muscle.  It 
consists  of  a  small  fasciculus  of  fibres, 
running  longitudinally  from  the  base, 
where  it  is  attached  to  the  os  hyoides, 
to  the  apex  of  the  tongue.  It  is  in  re- 
lation by  its  under  surface  with  the  ranine  artery. 

*  The  styloid  muscles  and  the  muscles  of  the  tongue.  1.  A  portion  of  the  temporal 
bone  of  the  left  side  of  the  skull,  including  the  styloid  and  mastoid  processes,  and  the 
meatus  auditorius  externus.  2,  2.  The  right  side  of  the  fower  jaw,  divided  at  its  sym- 
physis ;  the  left  side  having  been  removed.  3.  The  tongue.  4.  The  genio-hyoideus 
muscle.  5.  The  genio-hyo-glossus.  6.  The  hyo-glossus  muscle,  its  basio-glossus  portion. 
7.  Its  cerato-glossus  portion.  8.  The  anterior  fibres  of  the  lingualis  issuing  from  between 
the  hyo-glossus  and  genio-hyo-glossus.  9.  The  stylo-glossus  muscle,  with  a  small  portion 
of  the  stylo-maxillary  ligament.  10.  The  stylo-hyoid.  11.  The  stylo-pharyngeus  muscle 
12.  The  os  hyoides.  13.  The  thyro-hyoidean  membrane.  14.  The  thyroid  cartilage. 

15.  The  thyro-hyoideus   muscle  arising  from  the  oblique  line  on  the  thyroid  cartilage. 

16.  The  cricoid  cartilage.     17.  The  crico-thyroidean  membrane,  through  which  the  ope- 
ration of  laryngotomy  is  performed.     18.  The  trachea.     19.  The  commencement  ot  th« 


192  MUSCLES  OF  THE  PHARYNX. 

The  STYLO-GLOSSUS  arises  from  the  apex  of  the  styloid  process,  and 
from  the  stylo-maxillary  ligament ;  it  divides  upon  the  side  of  the  tongue 
into  two  portions,  one  transverse,  which  passes  transversely  inwards  be- 
tween the  two  portions  of  the  hyo-glossus,  and  is  lost  among  the  transverse 
fibres  of  the  substance  of  the  tongue,  and  another  longitudinal,  which 
spreads  out  upon  the  side  of  the  tongue  as  far  as  its  tip. 

Relations. — By  its  external  surface  with  the  internal  pterygoid  muscle, 
the  gustatory  nerve,  the  parotid  gland,  sublingual  gland,  and  the  mucous 
membrane  of  the  floor  of  the  tongue.  By  its  internal  surface  with  the 
tonsil,  the  superior  constrictor  muscle  of  the  pharynx,  and  the  hyo-glossus 
muscle. 

The  PALATO-GLOSSUS  passes  between  the  soft  palate,  and  the  side  of  the 
base  of  the  tongue,  forming  a  projection  of  the  mucous  membrane,  which 
is  called  the  anterior  pillar  of  the  soft  palate.  Its  fibres  are  lost  superiorly 
among  the  muscular  fibres  of  the  palato-pharyngeus,  and  inferiorly  among 
the  fibres  of  the  stylo-glossus  upon  the  side  of  the  tongue.  This  muscle 
with  its  fellow  constitutes  the  constrictor  isthmi  faucium. 

•fictions. — The  genio-hyo-glossus  muscle  effects  several  movements  of 
the  tongue,  as  might  be  expected  from  its  extent.  When  the  tongue  is 
steadied  and  pointed  by  the  other  muscles,  the  posterior  fibres  of  the  genio- 
hyo-glossus  would  dart  it  from  the  mouth,  while  its  anterior  fibres  would 
restore  it  to  its  original  position.  The  whole  length  of  the  muscle  acting 
upon  the  tongue,  would  render  it  concave  along  the  middle  line,  and  form 
a  channel  for  the  current  of  fluid  towards  the  pharynx,  as  in  sucking.  The 
apex  of  the  tongue  is  directed  to  the  roof  of  the  mouth,  and  rendered  con- 
vex from  before  backwards  by  the  linguales.  The  hyo-glossi,  by  drawing 
down  the  sides  of  the  tongue,  render  it  convex  along  the  middle  line.  It 
is  drawn  upwards  at  its  base  by  the  palato-glossi,  and  backwards  or  to 
either  side  by  the  stylo-glossi.  Thus  the  whole  of  the  complicated  move- 
ments of  the  tongue  may  be  explained,  by  reasoning  upon  the  direction 
of  the  fibres  of  the  muscles,  and  their  probable  actions.  The  palato-glossi 
muscles,  assisted  by  the  uvula,  have  the  power  of  closing  the  fauces  com 
pletely,  an  action  which  takes  place  in  deglutition. 

Fifth  Group. — Muscles  of  the  Pharynx. 

Constrictor  inferior, 
Constrictor  medius, 
Constrictor  superior, 
Stylo-pharyngeus, 
Palato-pharyngeus. 

Dissection. — To  dissect  the  pharynx,  the  trachea  and  (Esophagus  are  to 
5e  cut  through  at  the  lower  part  of  the  neck,  and  drawn  upwards  by  di- 
viding the  loose  cellular  tissue  which  connects  the  pharynx  to  the  vertebral 
column.  The  saw  is  then  to  be  applied  behind  the  styloid  processes,  and 
the  base  of  the  skull  sawn  through.  The  vessels  and  loose  structure  should 
be  removed  from  the  preparation,  and  the  pharynx  stuffed  with  tow  or 
wool  for  the  purpose  of  distending  it,  and  rendering  the  muscle  more  easy 
of  dissection.  The  pharynx  is  invested  by  a  proper  pharyngeal  fascia. 

The  CONSTRICTOR  INFERIOR,  the  thickest  of  the  three  muscles  of  this 
class,  arises  from  the  upper  rings  of  the  trachea,  the  cricoid  cartilage,  and 
ihe  oblique  line  of  the  thyroid.  Its  fibres  spread  out  and  are  inserted  into 


CONSTRICTOR    SUPERIOR — STYLO-PHARYNGEUS.  193 

the  fibrous  raphe  of  the  middle  of  the  pharynx,  the  inferior  fibres  being 
almost  horizontal,  and  the  superior  oblique,  and  overlapping  the  middle 
constrictor. 

Relations. — By  its  external  surface  with  the  anterior  surface  of  the  ver- 
tebral column,  the  longus  colli,  the  sheath  of  the  common  carotid  artery, 
the  sterno-thyroid  muscle,  the  thyroid  gland,  and  some  lymphatic  glands. 
By  its  internal  surface  with  the  middle  constrictor,  the  stylo-pharyngeus, 
the  palato-pharyngeus,  and  the  mucous  membrane  of  the  pharynx.  By  its 
lower  border,  near  the  cricoid  cartilage,  it  is  in  relation  with  the  recurrent 
nerve  ;  and  by  the  upper  border  with  the  superior  laryngeal  nerve.  The 
fibres  of  origin  of  this  muscle  are  blended  with  those  of  the  sterno-hyoid, 
sterno-thyroid,  and  crico-thyroid,  and  it  frequently  forms  a  tendinous  arch 
across  the  latter. 

This  muscle  must  be  removed  before  the  next  can  be  examined. 

The  CONSTRICTOR  MEDIUS  arises  from  the  great  cornu  of  the  os  hyoides, 
from  the  lesser  cornu,  and  from  the  stylo-hyoidean  ligament.  It  radiates 
from  its  origin  upon  the  side  of  the  pharynx,  the  lower  fibres  descending 
and  being  overlapped  by  the  constrictor  inferior,  and  the  upper  fibres 
ascending  so  as  to  cover  in  the  constrictor  superior.  It  is  inserted  into  the 
raphe  and  by  a  fibrous  aponeurosis  into  the  basilar  process  of  the  occipital 
bone. 

Relations. — By  its  external  surface  with  the  vertebral  column,  the  longus 
colli,  rectus  anticus  major,  the  carotid  vessels,  inferior  constrictor,  hyo- 
glossus  muscle,  lingual  artery,  pharyngeal  plexus  of  nerves,  and  some 
lymphatic  glands.  By  its  internal  surface,  with  the  superior  constrictor, 
stylo-pharyngeus,  palato-pharyngeus,  and  mucous  membrane  of  the  pha- 
rynx. 

The  upper  portion  of  this  muscle  must  be  turned  down,  to  bring  the 
whole  of  the  superior  constrictor  into  view  ;  in  so  doing,  the  stylo-pharyn- 
geus muscle  will  be  seen  passing  beneath  its  upper  border. 

The  CONSTRICTOR  SUPERIOR  is  a  thin  and  quadrilateral  plane  of  muscu- 
lar fibres  arising  from  the  extremity  of  the  molar  ridge  of  the  lower  jaw, 
from  the  pterygo-maxillary  ligament,  and  from  the  lower  half  of  the  inter- 
nal pterygoid  plate,  and  inserted  into  the  raphe  and  basilar  process  of  the 
occipital  bone.  Its  superior  fibres  are  arched  and  leave  an  interval  be- 
tween its  upper  border  and  the  basilar  process,  which  is  deficient  in  mus- 
.  cular  fibres,  and  it  is  overlapped  inferiorly  by  the  middle  constrictor. 
Between  the  side  of  the  pharynx  and  the  ramus  of  the  lower  jaw  is  a 
triangular  interval,  the  maxillo-pharyngeal  space,  wrhich  is  bounded  on  the 
inner  side  by  the  superior  constrictor  muscle ;  on  the  outer  side  by  the 
internal  pterygoid  muscle ;  and  behind  by  the  rectus  anticus  major  and 
vertebral  column.  In  this  space  are  situated  the  internal  carotid  artery, 
the  internal  jugular  vein,  and  the  glosso-pharyngeal,  pneumogastric,  spinal 
accessory,  and  hypo-glossal  nerve. 

Relations.  —  By  its  external  surface  with  the  vertebral  column  and  its 
muscles,  behind ;  with  the  vessels  and  nerves  contained  in  the  maxillo- 
pharyngeal  space  laterally,  the  middle  constrictor,  stylo-pharyngeus.  and 
tensor  palati  muscle.  By  its  internal  surface  with  the  levator  palati, 
palato-pharyngeus,  tonsil,  and  mucous  membrane  of  the  pharynx,  the 
pharyngeal  fascia  being  interposed. 

The  STYLO-PHARYNGEUS  is  a  long  and  slender  muscle  arising  from  the 
inner  side  of  the  base  of  the  styloid  process ;  it  descends  between  the 
17  N 


194 


MUSCLES  OF  THE  SOFT  PALATE. 


Fig.  Ill* 


superior  and  middle  constrictor  muscles,  and 
spreads  out  beneath  the  mucous  membrane 
of  the  pharynx,  its  inferior  fibres  being  in- 
serted into  the  posterior  border  of  the  thyroid 
cartilage. 

Relations.  —  By  its  external  surface  with 
the  stylo-glossus  muscle,  external  carotid 
artery,  parotid  gland,  and  the  middle  con- 
strictor. By  its  internal  surface  with  the 
internal  carotid  artery,  internal  jugular  vein, 
superior  constrictor,  palato-pharyngeus,  and 
mucous  membrane.  Along  its  lower  border 
is  seen  the  glosso-pharyngeal  nerve  which 
crosses  it,  opposite  the  root  of  the  tongue,  to 
pass  between  the  superior  and  middle  con- 
strictor and  behind  the  hyo-glossus. 

The  palato-pharyngeus  is  described  with 
the  muscles  of  the  soft  palate.  It  arises  from 
the  soft  palate,  and  is  inserted  into  the  inner  surface  of  the  pharynx,  and 
posterior  border  of  the  thyroid  cartilage. 

Actions. — The  three  constrictor  muscles  are  important  agents  in  deglu- 
tition ;  they  contract  upon  the  morsel  of  food  as  soon  as  it  is  received  by 
the  pharynx,  and  convey  it  downwards  into  the  resophagus.  The  stylo- 
pharyngei  draw  the  pharynx  upwards  and  widen  it  laterally.  The  palato- 
pharyngei  also  draw  it  upwards,  and  with  the  aid  of  the  uvula  close  the 
opening  of  the  fauces. 

Sixth  Group. — Muscles  of  the  Soft  Palate. 

Levator  palati, 
Tensor  palati, 
Azygos  uvulae, 
Palato-glossus, 
Palato-pharyngeus. 

Dissection.  —  To  examine  these  muscles,  the  pharynx  must  be  opened 
from  behind,  and  the  mucous  membrane  carefully  removed  from  off  the 
posterior  surface  of  the  soft  palate. 

The  LEVATOR  PALATI,  a  moderately  thick  muscle,  arises  from  the  ex- 
tremity of  the  petrous  bone  and  from  the  posterior  and  inferior  aspect  of 
the  Eustaehian  tube,  and  passing  down  by  the  side  of  the  posterior  nares 
spreads  out  in  the  structure  of  the  soft  palate  as  far  as  the  middle  line. 

Relations. — Externally  with  the  tensor  palati  and  superior  constrictor 
muscle ;  internally  and  posteriorly  with  the  mucous  membrane  of  the 
pharynx  and  soft  palate ;  and  by  its  lower  border  with  the  palato-pha- 
ryngeus. 

*  A  side  view  of  the  muscles  of  the  pharjwix.  1.  The  trachea.  2.  The  cncoid  car- 
tilage. 3.  The  crico-thyroid  membrane.  4.  The  thyroid  cartilage.  5.  The  thyro-hyoi- 
dcan  membrane.  6.  The  os  hyoides.  7.  The  stylo-hyoidean  ligament.  8.  The  oeso- 
phagus. 9.  The  inferior  constrictor.  10.  The  middle  constrictor.  11.  The  superior 
constrictor.  12.  The  stylo-pharyngeus  muscle  passing  down  between  the  superior  and 
middle  constrictor.  13.  The  upper  concave  border  of  the  superior  constrictor;  at  this 
point  the  muscular  fibres  of  the  pharynx  are  deficient.  14.  The  pterygo-maxil'ary  lij;a- 
aient.  15.  The  buccinator  muscle.  16.  The  orbicularis  oris.  17.  The  mylo-liyoideus. 


PALATO-GLOSSUS — PALATO-PHARYNGEUS.         195 

This  muscle  must  be  turned  down  from  pig  112» 

its  origin  on  one  side,  and  removed,  and  the 
superior  constrictor  dissected  away  from  its 
pterygoid  origin,  to  bring  the  next  muscle 
into  view. 

The  TENSOR  PALATI  (circumflexus)  is  a 
slender  and  flattened  muscle ;  it  arises  from 
the  scaphoid  fossa  at  the  base  of  the  inter- 
nal pterygoid  plate  and  from  the  anterior 
aspect  of  the  Eustachian  tube.  It  descends 
to  the  hamular  process,  around  which  it 
turns  and  expands  into  a  tendinous  aponeu- 
rosis,  which  is  inserted  into  the  transverse 
ridge  on  the  horizontal  portion  of  the  palate  bone,  and  into  the  raphe. 

Relations. — By  its  external  surface  writh  the  internal  pterygoid  muscle  ; 
by  its  internal  surface  with  the  levator  palati,  internal  pterygoid  plate, 
and  superior  constrictor.  In  the  soft  palate,  its  tendinous  expansion  is 
placed  in  front  of  the  other  muscles  and  in  contact  with  the  mucous  mem- 
brane. 

The  AZYGOS  UVULJE  is^ot  a  single  muscle,  as  might  be  inferred  from 
its  name,  but  a  pair  of  small  muscles  placed  side  by  side  in  the  middle 
line  of  the  soft  palate.  They  arise  from  the  spine  of  the  palate  bone,  and 
are  inserted  into  the  uvula.  By  their  anterior  surface  they  are  connected 
with  the  tendinous  expansion  of  the  levatores  palati,  and  by  the  posterior 
with  the  mucous  membrane. 

The  two  next  muscles  are  brought  into  view  throughout  the  whole  of 
their  extent,  by  raising  the  mucous  membrane  from  off  the  pillars  of  the 
soft  palate  at  each  side. 

The  PALATO-GLOSSUS  (constrictor  isthmi  faucium)  is  a  small  fasciculus 
of  fibres  that  arises  in  the  soft  palate,  and  descends  to  be  inserted  into  the 
side  of  the  tongue.  It  is  the  projection  of  this  small  muscle,  covered  by 
mucous  membrane,  that  forms  the  anterior  pillar  of  the  soft  palate.  It  haf 
been  named  constrictor  isthmi  faucium  from  a  function  it  performs  in 
common  with  the  palato-pharyngeus,  viz.  of  constricting  the  opening  of 
the  fauces. 

The  PALATO-PHARYNGEUS  forms  the  posterior  pillar  of  the  fauces ;  it 
arises  by  an  expanded  fasciculus  from  the  lower  part  of  the  soft  palate, 
where  its  fibres  are  continuous  with  those  of  the  muscle  of  the  opposite 

*  The  muscles  of  the  soft  palate.  1.  A  transverse  section  through  the  middle  of  the 
base  of  the  skull,  dividing  the  basilar  process  of  the  occipital  bone  in  the  middle  line, 
and  the  petrous  portion  of  the  temporal  bone  at  each  side.  2.  The  vomer  covered  by 
mucous  membrane  and  separating  the  two  posterior  nares.  3,  3.  The  Eustachian  tubes. 
4.  The  levator  palati  muscle  of  the  left  side ;  the  right  has  been  removed.  5.  The  ha- 
mular process  of  the  internal  pterygoid  plate  of  the  left  side,  around  which  the  aponeu- 
rosis  of  the  tensor  palati  is  seen  turning.  6.  The  pterygo-m axillary  ligament.  7.  The 
superior  constrictor  muscle  of  the  left  side,  turned  aside.  8.  The  azygos  uvulae  muscle. 
9.  The  internal  pterygoid  plate.  10.  The  external  pterygoid  plate.  11.  The  tensor  pa- 
lati muscle.  12.  Its  aponeurosis  expanding  in  the  structure  of  the  soft  palate.  13.  The 
external  pterygoid  muscle.  14.  The  attachments  of  two  pairs  of  muscles  cut  short;  the 
superior  pair  belong  to  the  genio-hyo-glossi  muscles ;  the  inferior  pair  to  the  genio- 
hyoidei.  15.  The  attachment  of  the  rnylo-hyoideus  of  one  side  and  part  of  the  opposite. 
16.  The  anterior  attachments  of  the  digastric  muscles.  17.  The  depression  on  the  lower 
jaw  corresponding  with  the  submaxillary  gland.  The  depression  above  the  mylo-hyH 
deus,  on  which  the  number  15  rests,  corresponds  with  the  situation  of  the  sublinguaJ 
gland. 


196  PR^EVERTEBRAL    MUSCLES. 

side  ;  and  is  inserted  into  the  posterior  border  of  the  thyroid  cartilage. 
This  muscle  is  broad  above  where  it  forms  the  whole  thickness  of  the 
lower  half  of  the  soft  palate,  narrow  in  the  posterior  pillar,  and  again  broad 
and  thin  in  the  pharynx  where  it  spreads  out  previously  to  its  insertion. 

Relations. — In  the  soft  palate  it  is  in  relation  with  the  mucous  membrane 
both  by  its  anterior  and  posterior  surface  ;  above,  with  the  muscular  layer 
formed  by  the  levator  palati,  and  below  with  the  mucous  glands  situated 
along  the  margin  of  the  arch  of  the  palate.  In  the  posterior  pillar  of  the 
palate,  it  is  surrounded  for  two-thirds  of  its  extent  by  mucous  membrane 
In  the  pharynx,  it  is  in  relation  by  its  outer  surface  with  the  superior  and 
middle  constrictor  muscles,  and  by  its  inner  surface  with  the  mucous 
membrane  of  the  pharynx,  the  pharyngeal  fascia  being  interposed. 

Actions. — The  azygos  uvulae  shortens  the  uvula.  The  levator  palati 
raises  the  soft  palate,  while  the  tensor  spreads  it  out  laterally  so  as  to  form 
a  septum  between  the  pharynx  and  posterior  nares.  Taking  its  fixed  point 
from  below,  the  tensor  palati  will  dilate  the  Eustachian  tube.  The  palato- 
glossus  and  pharyngeus  constrict  the  opening  of  the  fauces,  and  by  draw- 
ing down  the  soft  palate  they  serve  to  press  the  mass  of  food  from  the 
dorsum  of  the  tongue  into  the  pharynx. 

Seventh  Group. — Prcevertebral  Muscles. 

Rectus  anticus  major, 
Rectus  anticus  minor, 
Scalenus  anticus, 
Scalenus  posticus, 
Longus  colli. 

Dissection. — These  muscles  have  already  been  exposed  by  the  removal 
of  the  face  from  the  anterior  aspect  of  the  vertebral  column;  all  that  is 
further  needed  is  the  removal  of  the  fascia  by  which  they  are  invested. 

The  RECTUS  ANTICUS  MAJOR,  broad  and  thick  above,  and  narrow  and 
pointed  below,  arises  from  the  anterior  tubercles  of  the  transverse  processes 
of  the  third,  fourth,  fifth,  and  sixth  cervical  vertebras,  and  is  inserted  into 
the  basilar  process  of  the  occipital  bone. 

Relations. — By  its  anterior  surface  with  the  pharynx,  the  internal  carotid 
artery,  internal  jugular  vein,  superior  cervical  ganglion,  sympathetic  nerve, 
pneumogastric,  and  spinal  accessory  nerve.  By  its  posterior  surface  with 
the  longus  colli,  rectus  anticus  minor,  and  superior  cervical  vertebrae. 

The  RECTUS  ANTICUS  MINOR  arises  from  the  anterior  border  of  the  la- 
teral mass  of  the  atlas,  and  is  inserted  into  the  basilar  process ;  its  fibres 
being  directed  obliquely  upwards  and  inwards. 

Relations. — By  its  anterior  surface  with  the  rectus  anticus  major,  and 
externally  with  the  superior  cervical  ganglion  of  the  sympathetic.  By  its 
posterior  surface  with  the  articulation  of  the  condyle  of  the  occipital  bone 
with  the  atlas,  and  with  the  anterior  occipito-atloid  ligament. 

The  SCALENUS  ANTICUS  is  a  triangular  muscle,  as  its  name  implies, 
situated  at  the  root  of  the  neck  and  appearing  like  a  continuation  of  the 
rectus  anticus  major ;  it  arises  from  the  anterior  tubercles  of  the  transverse 
processes  of  the  third,  fourth,  fifth,  and  sixth  cervical  vertebras,  and  is  in- 
serted into  the  tubercle  upon  the  inner  border  of  the  first  rib. 

Relations.  —  By  its  anterior  surface  with  the  stern o-mastoid  and  omo- 
hyoid  muscle,  with  the  cervicalis  superficialis  and  posterior  scapular  artery, 


SCALENUS    POSTICUS LOXGUS    COLLI. 


197 


Fig.  113.f 


with  the  phrenic  nerve,  and  with  the  subclavian  vein,  by  which  it  is  se- 
parated from  the  subclavius  muscle  and  clavicle.  By  its  posterior  surface 
with  the  nerves  which  go  to  form  the  brachial  plexus,  and  below  with  the 
subclavian  artery.  By  its  inner  side  it  is  separated  from  the  longus  colli 
by  the  vertebral  artery.  Its  relations  with  the  subclavian  artery  and  vein 
are  very  important,  the  vein  being  before  and  the  artery  behind  the 
muscle.* 

The  SCALENUS  POSTICUS  arises  from  the 
posterior  tubercles  of  all  the  cervical  ver- 
tebrae excepting  the  first.  It  is  inserted  by 
two  fleshy  fasciculi  into  the  first  and  second 
ribs.  The  anterior  (scalenus  medius)  of  the 
two  fasciculi  is  large,  and  occupies  all  the 
surface  of  the  first  rib  between  the  groove 
for  the  subclavian  artery  and  the  tuberosity. 
The  posterior  (scalenus  posticus)  is  small, 
and  is  attached  to  the  second  rib.  Albinus 
and  Soemmering  make  five  scaleni. 

Relations.  —  By  its  anterior  surface  with 
the  brachial  plexus  and  subclavian  artery ; 
posteriorly  with  the  levator  anguli  scapula?, 
cervicalis  ascendens,  transversalis  colli,  and 
sacro-lumbalis ;  internally  with  the  first  in- 
tercostal muscle,  the  first  rib,  the  inter- 
transverse  muscles,  and  cervical  vertebra ; 
and  externally  with  the  sterno-mastoid,  omo- 
hyoid,  supra-scapular  and  posterior  scapu- 
lar arteries. 

The  LONGUS  COLLI  is  a  long  and  flat  muscle,  consisting  of  two  portions. 
The  upper  arises  from  the  anterior  tubercle  of  the  atlas,  and  is  inserted 
into  the  transverse  processes  of  the  third,  fourth,  and  fifth  cervical  verte- 
bra. The  lower  portion  arises  from  the  bodies  of  the  second  and  third, 
and  transverse  processes  of  the  fourth  and  fifth,  and  passes  down  the  neck, 
to  be  inserted  into  the  bodies  of  the  three  lower  cervical  and  three  upper 
dorsal  vertebra.  We  should  thus  arrange  these  attachments  in  a  tabular 
form : — 


Upper 
portion. 

Lower 
portion. 


Origin.  Insertion. 

Atlas    -     -     -      <  3d,  4th,  and  5th  transverse  processes. 

2d  and  3d  bodies  C  3  lower  cervical  vertebra,  bodies. 
4th  and  5th  trans-  < 
verse  processes.  (  3  upper  dorsal,  bodies. 


In  general  terms,  the  muscle  is  attached  to  the  bodies  and  transverse 

*  la  a  subject  dissected  in  the  school  of  the  Middlesex  hospital  during  the  winter  of 
1841  by  Mr.  Joseph  Rogers,  the  subclavian  artery  of  the  left  side  was  placed  with  the 
vein  in  front  of  the  scalenus  anticus  muscle. 

•j-  The  proevertebral  group  of  muscles  of  the  neck.  1.  The  rectus  anticus  major  mus- 
cle. 2.  The  scalenus  anticus.  3.  The  lower  part  of  the  longus  colli  of  the  right  sHe.- 
it  is  concealed  superiorly  by  the  rectus  anticus  major.  4.  The  rectus  anticus  minor  5. 
The  upper  portion  of  the  longus  colli  muscle.  0.  Its  lower  portion;  the  figure  'c«ts 
upon  the  seventh  cervical  vertebra.  7.  The  scalenus  posticus.  8.  The  rectus  lateralis  of 
the  left  side.  9.  One  of  the  intertransversales  muscles. 

17* 


J98  MUSCLES    OF    THE    BACK. 

processes  of  the  five  superior  cervical  vertebrae  above,  and  to  the  boaies 
of  the  last  three  cervical  and  first  three  dorsal  below. 

Relations.  —  By  its  anterior  surface,  with  the  pharynx,  oesophagus,  the 
sheath  of  the  common  carotid,  internal  jugular  vein  and  pneumogastric 
nerve,  the  sympathetic  nerve,  inferior  laryngeal  nerve,  and  inferior  thyroid 
artery.  By  its  posterior  surface  it  rests  upon  the  cervical  and  upper  dor- 
sal vertebrse. 

Actions. — The  rectus  anticus  major  and  minor  preserve  the  equilibrium 
of  the  head  upon  the  atlas ;  and,  acting  conjointly  with  the  longus  colli, 
flex  and  rotate  the  head  and  the  cervical  portion  of  the  vertebral  column. 
The  scaleni  muscles,  taking  their  fixed  point  from  below,  are  flexors  of 
the  vertebral  column ;  and,  from  above,  elevators  of  the  ribs,  and  there- 
fore inspiratory  muscles. 

Eighth  Group. — Muscles  of  the  Larynx. 

These  muscles  are  described  with  the  anatomy  of  the  larynx,  in  Chap- 
ter XI. 

MUSCLES    OF    THE    TRUNK. 

The  muscles  of  the  trunk  may  be  subdivided  into  four  natural  groups ; 
viz. 

1.  Muscles  of  the  back.  3.  Muscles  of  the  abdomen. 

2.  Muscles  of  the  thorax.  4.  Muscles  of  the  perineum. 

1.  Muscles  of  the  Back. — The  region  of  the  back,  in  consequence  of  its 
extent,  is  common  to  the  neck,  the  upper  extremities,  and  the  abdomen. 
The  muscles  of  which  it  is  composed  are  numerous,  and  maybe  arranged 
into  six  layers. 

First  Layer.  (Cervical  Group.) 

T  Cervicalis  ascendens, 

us'  ,      .  Transversalis  colli, 

Latissimus  dorsi.  Trachelo-mastoideus, 

Second  Layer.  Complexus. 

T  Fifth  Layer. 

Levator  anguh  scapulae,  _•      ,  „ 

Rhomboideus  minor,  .     (D°rsa  G™UPO 

Rhomboideus  major.  Semi-spma  is  dorsi, 

bemi-spmalis  colli. 
Third  Layer.  (Cervical  Group.) 

Kectus  posticus  major, 

Serratus  posticus  superior,  Rectus  posticus  minor, 

Serratus  posticus  inferior,  Rectus  lateralis, 

Splenius  capitis,  Obliquus  inferior, 

Splenius  colli.  Obliquus  superior. 

Sixth  Layer. 
Fourth  Layer.  ,,  ,,.,.1 

Multmdus  spinse, 

(Dorsal  Group.)  Levatores  costarum, 

Sacro-lumbalis,  Supra-spinales, 

Longissimus  dorsi,  Inter-spinales, 

Spmalis  dorsi.  Inter-transversales. 


MUSCLES    OF   THE    BACK.  li)9 

First  Layer. 

Dissection. — The  muscles  of  this  layer  are  to  be  dissected  by  making 
an  incision  along  the  middle  line  of  the  back,  from  the  tubercle  on  the 
occipital  bone  to  the  coccyx.  From  the  upper  point  of  this  incision  carry 
a  second  along  the  side  of  the  neck,  to  the  middle  of  the  clavicle.  Infe- 
riorly,  an  incision  must  be  made  from  the  extremity  of  the  sacrum,  along 
the  crest  of  the  ileum,  to  about  its  middle.  For  the  convenience  of  dis- 
section, a  fourth  may  be  carried  from  the  middle  of  the  spine  to  the  aero 
mion  process.  The  integument  and  superficial  fascia,  together,  are  to  be 
dissected  off  the  muscles,  in  the  course  of  their  fibres,  over  the  whole  of 
this  region. 

The  TRAPEZIUS  muscle  (trapezium,  a  quadrangle  with  unequal  sides) 
arises  from  the  superior  curved  line  of  the  occipital  bone,  from  the  liga- 
mentum  nuchae,  supra-spinous  ligament,  and  spinous  processes  of  the  last 
cervical  and  all  the  dorsal  vertebrae.  The  fibres  converge  from  these 
various  points,  and  are  inserted  into  the  scapular  third  of  the  clavicle,  the 
acromion  process,  and  the  whole  length  of  the  upper  border  of  the  spine 
of  the  scapula.  The  inferior  fibres  become  tendinous  near  the  scapula, 
and  glide  over  the  triangular  surface  at  the  posterior  extremity  of  its  spine, 
upon  a  bursa  mucosa.  When  the  trapezius  is  dissected  on  both  sides, 
the  two  muscles  resemble  a  trapezium,  or  diamond-shaped  quadrangle,  on 
the  posterior  part  of  the  shoulders :  hence  the  muscle  was  formerly  named 
cucullaris  (cucullus,  a  monk's  cowl).  The  cervical  and  upper  part  of  the 
dorsal  portion  of  the  muscle  is  tendinous  at  its  origin,  and  forms,  with  the 
muscle  of  the  opposite  side,  a  kind  of  tendinous  ellipse. 

Relations.  —  By  its  superficial  surface,  with  the  integument  and  super- 
ficial fascia,  to  which  it  is  closely  adherent  by  its  cervical  portion,  loosely 
by  its  dorsal  portion.  By  its  deep  surface,  from  above  downwards,  with 
the  complexus,  splenius,  levator  anguli  scapulae,  supra-spinatus,  a  smalt 
portion  of  the  serratus  posticus  superior,  rhomboideus  minor,  rhomboideus 
major,  intervertebral  aponeurosis  which  separates  it  from  the  erector 
spince,  and  with  the  latissimus  dorsi.  The  anterior  border  of  the  cervical 
portion  of  this  muscle  forms  the  posterior  boundary  of  the  posterior  tri- 
angle of  the  neck.  The  clavicular  insertion  of  the  muscle  sometimes  ad- 
vances to  the  middle  of  the  clavicle,  or  as  far  as  the  outer  border  of  the 
sterno-mastoid,  and  occasionally  it  has  been  seen  to  overlap  the  latter. 
This  is  a  point  of  much  importance  to  be  borne  in  mind  in  the  operation 
for  ligature  of  the  subclavian  artery.  The  spinal  accessory  nerve  passes 
beneath  the  anterior  border,  near  to  the  clavicle,  previously  to  its  distribu 
tion  to  the  muscle. 

The  ligamentum  nuchce.  is  a  thin  cellulo-fibrous  layer  extended  from  tht 
tubercle  and  spine  of  the  occipital  bone,  to  the  spinous  process  of  the 
seventh  cervical  vertebra,  where  it  is  continuous  \vith  the  supra-spinous 
ligament.  It  is  connected  with  the  spinous  processes  of  the  rest  of  the 
cerviral  verteorae,  with  the  exception  of  the  atlas,  by  means  of  a  small 
fibrous  slip  which  is  sent  off  by  each.  It  is  the  analogue  of  an  important 
elastic  ligament  in  animals. 

The  LATISSIMUS  DORSI  muscle  covers  the  whole  of  the  lower  part  of  fhe 
back  and  loins.  It  arises  from  the  spinous  processes  of  the  seven  inferior 
dorsal  vertebrae,  from  all  the  lumbar  and  sacral  spinous  processes,  from  the 
posterior  third  of  the  crest  of  the  ilium,  and  from  the  three  lower  ribs;  the 


i>00  MUSCLES   OF   THE   BACK. 

latter  origin  takes  place  by  muscular  slips,  which  indigitate  with  the  ex- 
ternal oblique  muscle  of  the  abdomen.     The  fibres  from  this  extensive 

Fig.  J14.» 


origin  converge  as  they  ascend,  and  cross  the  inferior  angle  of  the  scapula ; 
they  then  curve  around  the  lower  border  of  the  teres  major  muscle,  and 
terminate  in  a  short  quadrilateral  tendon, f  which  lies  in  front  of  the  tendon 
of  the  teres,  and  is  inserted  into  the  bicipital  groove.  A  synovial  bursa  is 
interposed  between  the  muscle  and  the  lower  angle  of  the  scapula,  and 

*  The  first  and  second  and  part  of  the  third  layer  of  muscles  of  the  back  ;  the  first 
layer  being  shown  upon  the  right,  and  the  second  on  the  left  side.  1.  The  trapezius 
muscle.  2.  The  tendinous  portion  which,  with  a  corresponding  portion  in  the  opposite 
muscle,  forms  the  tendinous  ellipse  on  the  back  of  the  neck.  3.  The  acromicn  process 
and  spine  of  the  scapula.  4.  The  latissimus  dorsi  muscle.  5.  The  deltoid.  6.  Tho 
muscles  of  the  dorsum  of  the  scapula,  infra-spinatus,  teres  minor,  and  teres  major.  7. 
The  external  oblique  muscle.  8.  The  glutens  medius.  9.  The  glutei  maximi.  10.  The 
levator  anguli  scapulae.  11.  The  rhomboideus  minor.  12.  The  rhomboideua  major. 
13.  The  splenius  capitis;  the  muscle  immediately  above,  and  overlaid  by  the  splemus, 
is  the  complexus.  14.  The  splenius  colli,  only  partially  seen;  the  common  origin  of  the 
splenius  is  seen  attached  to  the  spinous  processes  below  the  lower  border  of  the  rhom- 
boideus major.  15.  The  vertebral  aponeurosis.  16.  The  serratus  posticus  inferior.  17. 
The  supra-spinatus  muscle.  18.  The  infra-spinatus.  19.  The  teres  minor  muscle.  20. 
The  teres  major.  21.  The  long  head  of  the  triceps,  passing  between  the  teres  minor 
ind  major  to  the  upper  arm.  22.  The  serratus  magnus,  proceeding  forwards  from  its 
origin  at  the  base  of  the  scapula.  23.  The  internal  oblique  muscle. 

{•A  small  muscular  fasciculus  from  the  pectoralis  major  is  sometimes  found  connected 
with  »Uis  tendon. 


MUSCLES    OF   THE    BACK.  201 

another  between  its  tendon  and  that  of  the  teres  major.  The  muscle  fre- 
quently receives  a  small  fasciculus  from  the  scapula  as  it  crosses  its  inferior 
angle. 

Relations. — By  its  superficial  surface -\\i\h  the  integument  and  superficial 
fascia;  the  latter  is  very  dense  and  fibrous  in  the  lumbar  region;  and  with 
the  trapezius.  By  its  deep  surface  from  below  upwards,  with  the  erector 
spinoe,  serratus  posticus  inferior,  intercostal  muscles  and  ribs,  rhomboideus 
major,  inferior  angle  of  the  scapula  and  teres  major.  The  latissimus  dorsi, 
with  the  teres  major,  forms  the  posterior  border  of  the  axilla. 

Second  Layer. 

Dissection. — This  layer  is  brought  into  view  by  dividing  the  two  pre- 
ceding muscles  near  their  insertion,  and  turning  them  to  the  opposite 
side. 

The  LEVATOR  ANGULI  SCAPULAE  arises  by  distinct  slips,  from  the 
posterior  tubercles  of  the  transverse  processes  of  the  four  upper  cervical 
vertebrae,  and  is  inserted  into  the  upper  angle  and  posterior  border  of 
the  scapula,  as  far  as  the  triangular  smooth  surface  at  the  root  of  its 
spine. 

Relations. — By  its  superficial  surface  with  the  trapezius,  sterno-mastoid 
and  integument.  By  its  deep  surface  with  the  splenius  colli,  transversalis 
colli,  cervicalis  ascendens,  scalenus  posticus,  and  serratus  posticus  supe- 
rior. The  tendons  of  origin  are  interposed  between  the  attachments  of  the 
scalenus  posticus  in  front,  and  the  splenius  colli  behind. 

The  RHOMBOIDEUS  MINOR  (rhombus,  a  parallelogram  with  four  equal 
sides)  is  a  narrow  slip  of  muscle,  detached  from  the  rhomboideus  major 
by  a  slight  cellular  interspace.  It  arises  from  the  spinous  process  of  the 
two  last  cervical  vertebra?  and  ligamentum  nuchse,  and  is  inserted  into  the 
edge  of  the  triangular  surface,  on  the  posterior  border  of  the  scapula. 

The  RHOMBOIDEUS  MAJOR  arises  from  the  spinous  processes  of  the  last 
cervical  and  four  upper  dorsal  vertebrae  and  from  the  inter-spinous  liga- 
ments ;  it  is  inserted  into  the  posterior  border  of  the  scapula  as  far  as  its 
inferior  angle.  The  upper  and  middle  portion  of  the  insertion  is  effected 
by  means  of  a  tendinous  band  which  is  attached  in  a  longitudinal  direction 
to  the  posterior  border  of  the  scapula. 

Relations. — By  their  superficial  surface  the  two  rhomboid  muscles  are 
in  relation  with  the  trapezius,  and  the  rhomboideus  major  with  the  latis- 
simus dorsi  and  integument.  By  their  deep  surface  they  cover  in  the  ser- 
ratus posticus  superior,  part  of  the  erector  spinse,  the  intercostal  muscles 
and  ribs. 

Third  Layer. 

Dissection. — The  third  layer  consists  of  muscles  which  arise  from  the 
spinous  processes  of  the  vertebral  column,  and  pass  outwards.  It  is  brought 
into  view  by  dividing  the  levator  anguli  scapulae  near  its  insertion,  and 
reflecting  the  two  rhomboid  muscles  upwards  from  their  insertion  into  the 
scapula.  The  latter  muscles  should  now  be  removed. 

The  SERRATUS  POSTICUS  SUPERIOR  is  situated  at  the  upper  part  of  the 
thorax  ;  it  arises  by  the  ligamentum  nuchae,  from  the  spinous  processes  of 
the  three  last  cervical  and  those  of  the  two  upper  dorsal  vertebrae.  The 
rpuscle  passes  obliquely  downwards,  and  outwards,  and  is  inserted  by  four 


202  MUSCLES    OF   THE    BACK. 

serrations  into  the  upper  border  of  the  second,  third,  fourth,  and  fifth 
ribs. 

Relations. — By  its  superficial  surface  with  the  trapezius,  rhomboideus 
major  and  minor,  and  serratus  magnus.  By  its  deep  surface  with  the 
splenius,  the  upper  part  of  the  erector  spinae,  the  intercostal  muscles  and 
ribs. 

The  SERRATUS  POSTICUS  INFERIOR  arises  from  the  processes  and  inter- 
spinous  ligaments  of  the  two  last  dorsal  and  three  upper  lumbar  vertebrae, 
and  passing  obliquely  upwards  is  inserted  by  four  serrations  into  the  lower 
border  of  the  four  lower  ribs.  Both  muscles  are  constituted  by  a  thin 
aponeurosis  for  about  half  their  extent. 

Relations. — By  its  superficial  surface  with  the  latissimus  dorsi,  its  tendi- 
nous origin  being  inseparably  connected  with  the  aponeurosis  of  that  muscle. 
By  its  deep  surface  with  the  aponeurosis  of  the  obliquus  internus,  with 
which  it  is  also  closely  adherent ;  with  the  erector  spins,  the  intercostal 
muscles  and  lower  ribs.  The  upper  border  is  continuous  with  a  thin  ten- 
dinous layer,  the  vertebral  aponeurosis.  The  Vertebral  aponeurosis  is  a 
thin  membranous  expansion  composed  of  longitudinal  and  transverse 
fibres,  and  extending  the  whole  length  of  the  thoracic  region.  It  is  at- 
tached mesially  to  the  spinous  processes  of  the  dorsal  vertebra?,  and  exter- 
nally to  the  angles  of  the  ribs;  superiorly  it  is  continued  upwards  beneath 
the  serratus  posticus  superior,  with  the  lower  border  of  which  it  is  some- 
times connected.  It  serves  to  bind  down  the  erector  spinae,  and  separate 
it  from  the  superficial  muscles. 

The  serratus  posticus  superior  must  be  removed  from  its  origin  and 
turned  outwards,  to  bring  into  view  the  whole  extent  of  the  splenius 
muscle. 

The  SPLENIDS  MUSCLE  is  single  at  its  origin,  but  divides  soon  after  into 
two  portions,  which  are  destined  to  distinct  insertions.  It  arises  by  the 
lower  half  of  the  ligamentum  nuchae,  from  the  spinous  processes  of  the 
five  last  cervical,  and  from  the  spinous  processes  and  interspinous  liga- 
ments of  the  six  upper  dorsal  vertebrae  ;  it  divides  as  it  ascends  the  neck 
into  the  splenius  capitis  and  colli.  The  splenius  capitis  is  inserted  into 
the  rough  surface  of  the  occipital  bone  between  the  two  curved  lines,  and 
into  the  mastoid  portion  of  the  temporal  bone. 

The  splenius  colli  is  inserted  into  the  posterior  tubercles  of  the  trans- 
verse processes  of  the  three  or  four  upper  cervical  vertebrae. 

Relations. — By  its  superficial  surface  with  the  trapezius,  sterno-mastoid, 
Jevator  anguli  scapulae,  rhomboideus  minor  and  major,  and  serratus  pos- 
ticus superior.  By  its  deep  surface  with  the  spinalis  dorsi,  longissimus  dorsi, 
semi-spinalis  colli,  complexus,  trachelo-mastoid,  and  transversalis  colli. 
The  tendons  of  insertion  of  the  splenius  colli  are  interposed  between  the 
insertions  of  the  levator  anguli  scapulae  in  front,  and  the  transversalis  colli 
behind. 

The  splenii  of  opposite  sides  of  the  neck  leave  between  them  a  trian- 
gular interval,  in  which  the  complexus  is  seen. 

Fourth  Layer. 

Dissection. — The  two  serrati  and  two  splenii  muscles  must  be  removed 
by  cutting  them  away  from  their  origins  and  insertions,  to  bring  the  fourth 
layer  into  view. 

Three  of  these  muscles,  viz.  sacro-lumbalis,  longissimus  dorsi,  and 


MUSCLES    OF    THE    BACK. 


203 


Fig.  115* 


spinalis  dorsi,  are  associated  under  the  name  of  erector  spinse.  They 
occupy  the  lumbar  and  dorsal  portion  of  the  back.  The  remaining  four 
are  situated  in  the  cervical  region. 

The  SACRO-LUMBALIS  and  LONGISSIMUS  DORSI  arise  by  a  common  origin 
from  the  posterior  third  of  the  crest  of  the  ilium,  from  the  posterior  surface 
of  the  sacrum,  and  from  the  lumbar  vertebra? ;  opposite  the  last  rib  a  line 
of  separation  begins  to  be  perceptible  between  the  two  muscles.  The 
sacro-lumbalis  is  inserted  by  separate  tendons  into  the  angles  of  the  six 
lower  ribs.  On  turning  the  muscle  a  little  out- 
wards, a  number  of  tendinous  slips  will  be  seen 
taking  their  origin  from  the  ribs,  and  terminating 
in  a  muscular  fasciculus,  by  which  the  sacro- 
lumbalis  is  prolonged  to  the  upper  part  of  the 
thorax.  This  is  the  musculus  accessorius  ad 
sacro-lumbalem :  it  arises  from  the  angles  of  the 
six  lower  ribs,  and  is  inserted  by  separate  ten- 
dons into  the  angles  of  the  six  upper  ribs. 

The  longissimus  dorsi  is  inserted  into  all  the 
ribs,  between  their  tubercles  and  angles. 

The  SPINALIS  DORSI  arises  from  the  spinous 
processes  of  the  two  upper  lumbar  and  three 
lower  dorsal  vertebree,  and  is  inserted  into  the 
spinous  processes  of  all  the  upper  dorsal  verte- 
brae ;  the  two  muscles  form  an  ellipse,  which 
appears  to  enclose  the  spinous  processes  of  all 
the  dorsal  vertebra. 

Relations.  —  The  erector  spinse  muscle  is  in 
relation  by  its  superficial  surface  (in  the  lumbar 
region)  with  the  conjoined  aponeurosis  of  the 
transversalis  and  internal  oblique  muscle,  which 
separates  it  from  the  aponeurosis  of  the  serratus 
posticus  inferior,  and  longissimus  dorsi;  (in  the 
dorsal  region)  with  the  vertebral  aponeurosis, 
which  separates  it  from  the  latissimus  dorsi, 
trapezius,  and  serratus  posticus  superior,  and 
with  the  splenius.  By  its  deep  surface  (in* the 
lumbar  region)  with  the  multifidus  spinaa,  trans- 
verse processes  of  the  lumbar  vertebrae,  and  with  the  middle  layer  of  the 
aponeurosis  of  the  transversalis  abdominis,  which  separates  it  from  the 
quadratus  lumborum ;  (in  the  dorsal  region)  with  the  multifidus  spinae, 
semi-spinalis  dorsi,  levatores  costarum,  intercostal  muscles,  and  ribs  as 
far  as  their  angles.  Internally  or  mesially  with  the  multifidus  spinse,  and 
semi-spinalis  dorsi,  which  separate  it  from  the  spinous  processes  and 
arches  of  the  vertebrae. 

The  two  layers  of  aponeurosis  of  the  transversalis  abdominis,  together 

*  The  fourth  and  fifth,  and  part  of  the  sixth  layer  of  the  muscles  of  the  back.  1.  The 
common  origin  of  the  erector  spinae  muscle.  2.  The  sacro-lumbalis.  3.  The  longissi- 
mus dorsi.  4.  The  spinalis  dorsi.  5.  The  cervicalis  ascendens.  6.  The  transversalis 
colli.  7.  The  trachelo-mastoideus.  8.  The  complexus.  9.  The  transversalis  colli, 
showing  its  origin.  10.  The  semi-spinalis  dorsi.  11.  The  semi-spinalis  colli.  12.  The 
rectus  posticus  minor.  13.  The  rectus  posticus  major.  14.  The  obliquus  suoerioi. 
15.  The  obliquus  inferior.  16.  The  multifidus  spinae.  17.  The  levatores  costarum 
IS.  Litertransversales.  19.  The  quadratus  lumborum. 


204  MUSCLES    OF   THE    BACK. 

with  the  spinal  column  in  the  lumbar  region,  and  the  vertebral  aponeu- 
rosis  with  the  ribs  and  spinal  column  in  the  dorsal  region,  form  a  com- 
plete osseo-aponeurotic  sheath  for  the  erector  spinae. 

The  CERVICALIS  ASCENDENS  is  the  continuation  of  the  sacro-lumbalis 
upwards  into  the  neck.  It  arises  from  the  angles  of  the  four  upper  ribs, 
and  is  inserted  by  slender  tendons  into  the  posterior  tubercles  of  the  trans- 
verse processes  of  the  four  lower  cervical  vertebrae. 

Relations. — By  its  superficial  surface  with  the  levator  anguli  scapulae ; 
by  its  deep  surface  with  the  upper  intercostal  muscles  and  ribs,  and  with 
the  intertransverse  mu  cles ;  externally  with  the  scalenus  posticus ;  and 
internally  with  the  transversalis  colli.  The  tendons  of  insertion  are  inter- 
posed between  the  attachments  of  the  scalenus  posticus  and  transversalis 
colli. 

The  TRANSVERSALIS  COLLI  would  appear  to  be  the  continuation  up- 
wards into  the  neck  of  the  longissimus  dorsi ;  it  arises  from  the  transverse 
processes  of  the  five  upper  dorsal  vertebrae,  and  is  inserted  into  the  pos- 
terior tubercles  of  the  transverse  processes  of  the  five  middle  cervical 
vertebrae. 

Relations.  —  By  its  superficial  surface  with  the  levator  anguli  scapulas, 
splenius  and  longissimus  dorsi.  By  its  deep  surface  with  the  complexus, 
trachelo-mastoideus  and  vertebra; ;  externally  with  the  musculus  accesso- 
rius  ad  sacro-lumbalem,  and  cervicalis  ascendens ;  internally  with  the 
trachelo-mastoideus  and  complexus.  The  tendons  of  insertion  of  this 
muscle  are  interposed  between  the  tendons  of  insertion  of  the  cervicalis 
ascendens  on  the  outer  side,  and  of  origin  of  the  trachelo-mastoid  on  the 
inner  side. 

The  TRACHELO-MASTOID  is  likewise  a  continuation  upwards  from  the 
longissimus  dorsi.  It  is  a  very  slender  and  delicate  muscle,  arising  from 
the  transverse  processes  of  the  four  upper  dorsal  and  four  lower  cervical 
vertebrae,  and  inserted  into  the  mastoid  process  to  the  inner  side  of  the 
digastric  fossa. 

Relations. — The  same  as  those  of  the  preceding  muscle,  excepting  that 
it  is  interposed  between  the  transversalis  colli  and  the  complexus.  Its 
tendons  of  attachment  are  the  most  posterior  of  those  which  are  connected 
with  the  posterior  tubercles  of  the  transverse  processes  of  the  cervical  ver- 
tebras. 

The  COMPLEXUS  is  a  large  muscle,  and  with  the  splenius  forms  the 
great  bulk  of  the  back  of  the  neck.  It  crosses  the  direction  of  the  splenius, 
arising  from  the  transverse  processes  of  the  four  upper  dorsal,  and  from 
the  transverse  and  articular  processes  of  the  four  lower  cervical  vertebrae, 
and  is  inserted  into  the  rough  surface  on  the  occipital  bone  between  the 
two  curved  lines,  near  the  occipital  spine.  A  large  fasciculus  of  the  com- 
plexus is  so  distinct  from  the  principal  mass  of  the  muscle  as  to  have  led 
to  its  description  as  a  separate  muscle  under  the  name  of  biventer  cervicis. 
This  appellation  is  not  inappropriate,  for  the  muscle  consists  of  a  central 
tendon,  with  two  fleshy  bellies.  The  complexus  is  crossed  in  the  upper 
part  of  the  neck  by  a  tendinous  intersection. 

Relations.  —  By  its  superficial  surface  with  the  trapezius,  splenius,1  tra- 
chelo-mastoid, transversalis  colli,  and  longissimus  dorsi.  By  its  deep  sur- 
face with  the  semi-spinalis  dorsi  and  colli,  the  recti  and  obliqui.  It  is 
separated  from  its  fellow  of  the  opposite  side  by  the  ligamentum  nuchae, 
and  from  the  semi-spinalis  colli  by  the  profunda  cervicis  artery  and  prin- 


MUSCLES    OF   THE    BACK.  205 

ceps  cervicis  branch  of  the  occipital,  and  by  the  posterior  cervical  plexus 
of  nerves. 

Fifth  Layer. 

Dissection. — The  muscles  of  the  preceding  layer  are  to  be  removed  by 
dividing  them  transversely  through  the  middle,  and  turning  one  extremity 
upwards,  the  other  downwards.  In  this  way  the  whole  of  the  muscles  of 
the  fourth  layer  may  be  got  rid  of,  and  the  remaining  muscles  of  the  spine 
brought  into  a  state  to  be  examined. 

The  SEMI-SPINALES  MUSCLES  are  connected  with  the  transverse  and 
spinous  processes  of  the  vertebrae,  spanning  one  half  of  the  vertebral 
column  ;  hence  their  name  semi-spinales. 

The  SEMI-SPINALIS  DORSI  arises  from  the  transverse  processes  of  the 
six  lower  dorsal  vertebra,  and  is  inserted  into  the  spinous  processes  of  the 
four  upper  dorsal,  and  two  lower  cervical  vertebrae. 

The  SEMI-SPINALIS  COLLI  arises  from  the  transverse  processes  of  the 
four  upper  dorsal  vertebrae,  and  is  inserted  into  the  spinous  processes  of 
the  four  upper  cervical  vertebras,  commencing  with  the  axis. 

Relations. — By  their  superficial  surface  the  semi-spinales  are  in  relation 
from  below  upwards  with  the  spinalis  dorsi,  longissimus  dorsi,  complexus, 
splenius,  with  the  profunda  cervicis  and  princeps  cervicis  artery,  and  pos- 
terior cervical  plexus  of  nerves.  By  their  deep  surface  with  the  multifidus 
spinoe  muscle. 

Occipital  Group. — This  group  of  small  muscles  is  intended  for  the  varied 
movements  of  the  cranium  on  the  atlas,  and  the  atlas  on  the  axis.  They 
are  extremely  pretty  in  appearance. 

The  RECTUS  POSTICUS  MAJOR  arises  from  the  spinous  process  of  the 
axis,  and  is  inserted  into  the  inferior  curved  line  of  the  occipital  bone. 

The  RECTUS  POSTICUS  MINOR  arises  from  the  spinous  tubercle  of  the 
atlas,  and  is  inserted  into  the  rough  surface  on  the  occipital  bone,  beneath 
the  inferior  curved  line. 

The  RECTUS  LATERALIS  is  extended  between  the  transverse  process  of 
the  atlas  and  the  occipital  bone  ;  it  arises  from  the  transverse  process  of 
the  atlas,  and  is  inserted  into  the  rough  surface  of  the  occipital  bone,  ex- 
ternal to  the  condyle. 

The  OBLIQUUS  INFERIOR  arises  from  the  spinous  process  of  the  axis,  and 
passes  obliquely  outwards  to  be  inserted  into  the  extremity  of  the  trans- 
verse process  of  the  atlas. 

The  OBLIQUUS  SUPERIOR  arises  from  the  extremity  of  the  transverse  pro- 
cess of  the  atlas,  and  passes  obliquely  inwards  to  be  inserted  into  the  rough 
surface  of  the  occipital  bone,  between  the  curved  lines. 

Relations. — By  their  superficial  surface  the  recti  and  obliqui  are  in  rela- 
tion with  a  strong  aponeurosis  which  separates  them  from  the  complexus. 
By  their  deep  surface  with  the  atlas  and  axis,  and  their  articulations.  The 
rectus  posticus  major  partly  covers  in  the  rectus  minor. 

The  rectus  lateralis  is  in  relation  by  its  anterior  surface  with  the  internal 
jugular  vein,  and  by  its  posterior  surface  with  the  vertebral  artery. 

Sixth  Layer. 

Dissection. — The  semi-spinales  muscles  must  both  be  removed  to  obtain 
a  good  view  of  the  multifidus  spinse  which  lies  beneath  them,  and  fills  up 
the  concavity  between  the  spinous  and  transverse  processes,  the  whole 
length  of  the  vertebral  column. 
18 


206  MUSCLES   OF   THE   BACK. 

The  MULTIFIDUS  SPIN^:*  consists  of  a  great  number  of  fleshy  fascicul. 
extending  between  the  transverse  and  spinous  processes  of  the  vertebrae, 
from  the  sacrum  to  the  axis.  Each  fasciculus  arises  from  a  transverse  pro- 
cess, and  is  inserted  into  the  spinous  process  of  the  first  or  second  vertebra 
above.  Some  deep  fasciculi  of  the  multifidus  spinae  have  recently  been 
described  by  Professor  Theile  under  the  name  of  rotatores  spines. 

Relations. — By  its  superficial  surface  with  the  longissimus  dorsi,  semi- 
spinalis  dorsi,  and  semi-spinalis  colli.  By  its  deep  surface  with  the  arches 
and  spinous  processes  of  the  vertebral  column,  and  in  the  cervical  region 
with  the  ligamentum  nuchae. 

The  LEVATORES  COSTARUM,  twelve  in  number  on  each  side,  arise  from 
the  transverse  processes  of  the  dorsal  vertebrae,  and  pass  obliquely  out- 
wards and  downwards  to  be  inserted  into  the  rough  surface  between  the 
tubercle  and  angle  of  the  rib  belowr  them.  The  first  of  these  muscles 
arises  from  the  transverse  process  of  the  last  cervical  vertebra,  and  the  last 
from  that  of  the  eleventh  dorsal.  The  levatores  of  the  inferior  ribs,  besides 
the  distribution  here  described,  send  a  fasciculus  downwards  to  the  second 
rib  below  their  origin,  and  consequently  are  inserted  into  two  ribs. 

Relations. — By  their  superficial  surface  with  the  longissimus  dorsi  and 
sacro-lumbalis.  By  their  deep  surface  with  the  intercostal  muscles  and 
ribs. 

The  SUPRA-SPINALIS  is  a  small  and  irregular  muscle  lying  upon  the 
spinous  processes  in  the  cervical  region  and  composed  of  several  fasciculi. 
The  fasciculi  arise  from  the  inferior  cervical  and  superior  dorsal  vertebrae, 
and  are  inserted  into  the  spinous  process  of  the  axis.  From  its  analogy 
to  the  spinalis  dorsi  this  muscle  has  been  named  spinalis  colli.  It  is 
sometimes  wanting. 

The  INTERSPINALES  are  small  muscular  slips  arranged  in  pairs  and  situ- 
ated between  the  spinous  processes  of  the  vertebrae.  In  the  cervical  re- 
gion there  are  six  pairs  of  these  muscles,  the  first  being  placed  between 
the  axis  and  third  vertebra,  and  the  sixth  between  the  last  cervical  and 
first  dorsal.  In  the  dorsal  region,  rudiments  of  these  muscles  are  occa- 
sionally met  with  between  the  upper  and  lowTer  vertebrae,  but  are  absent 
in  the  rest.  In  the  lumbar  region  there  are  six  pairs  of  interspinales,  the 
first  pair  occupying  the  interspinous  space  between  the  last  dorsal  and 
first  lumbar  vertebra,  and  the  last  the  space  between  the  fifth  lumbar  and 
sacrum.  They  are  thin  and  imperfectly  developed.  Rudimentary  inter- 
spinales are  occasionally  met  with  between  the  lower  part  of  the  sacrum 
and  the  coccyx ;  these  are  the  analogues  of  the  caudal  muscles  of  brutes ; 
in  man  they  have  been  named  collectively  the  extensor  coccygis. 

The  INTERTRANSVERSALES  are  small  quadrilateral  muscles  situated  be- 
tween the  transverse  processes  of  the  vertebras.  In  the  cervical  region 
they  are  arranged  in  pairs  corresponding  with  the  double  conformation  of 
the  transverse  processes,  the  vertebral  artery  and  anterior  division  of  the 
cervical  nerves  lying  between  them.  The  rectus  anticus  minor  and  rectus 
lateralis  represent  the  intertransversales  between  the  atlas  and  cranium. 
In  the  dorsal  region  the  anterior  intertransversales  are  represented  by  the 
intercostal  muscles,  while  the  posterior  are  mere  tendinous  bands,  mus- 
cular only  oetween  the  first  and  last  vertebrae.  In  the  lumbar  region,  the 

»  Professor  Theile  of  Berlin  has  examined  this  muscle  very  closely,  and  describes  a 
portion  of  it  under  the  name  of  ROTATOHES  SPIXJB,  which  seems  to  be  an  unnecessary 
complication. — G. 


MUSCLES    OF   THE    BACK.  207 

anterior  intertransversales  are  thin,  and  occupy  only  part  of  the  space  be- 
tween the  transverse  processes.     Analogues  of  posterior  intertransversales 
exist  in  the  form  of  small  muscular  fasciculi  (interobliqui)  extended  be 
tween  the  rudimentary  posterior  transverse  processes  of  the  lumbar  ver- 
icbrae. 

With  regard  to  the  origin  and  insertion  of  the  muscles  of  the  back,  the 
student  should  be  informed,  that  no  regularity  attends  their  attachments. 
At  the  best,  a  knowledge  of  their  exact  connexions,  even  were  it  possible 
to  retain  it,  would  be  but  a  barren  information,  if  not  absolutely  injurious, 
as  tending  to  exclude  more  valuable  learning.  I  have  therefore  endea- 
voured to  arrange  a  plan,  by  which  they  may  be  more  easily  recollected, 
by  placing  them  in  a  tabular  form  (p.  208),  that  the  student  may  see,  at 
a  single  glance,  the  origin  and  insertion  of  each,  and  compare  the  natural 
grouping  and  similarity  of  attachments  of  the  various  layers.  In  this 
manner  also  their  actions  will  be  better  comprehended,  and  learnt  with 
greater  facility. 

Actions. — The  upper  fibres  of  the  trapezius  draw  the  shoulder  upwards 
and  backwards ;  the  middle  fibres,  directly  backwards ;  and  the  lower 
downwards  and  backwards.  The  lower  fibres  also  act  by  producing  ro- 
tation of  the  scapula  upon  the  chest.  If  the  shoulder  be  fixed  the  upper 
fibres  will  flex  the  spine  towards  the  corresponding  side.  The  latissimus 
dorsi  is  a  muscle  of  the  arm,  drawing  it  backwards  and  downwards,  and 
at  the  same  time  rotating  it  inwards ;  if  the  arm  be  fixed,  the  latissimus 
dorsi  will  draw  the  spine  to  that  side,  and,  raising  the  lower  ribs,  be  an 
inspiratory  muscle  ;  and  if  both  arms  be  fixed,  the  two  muscles  will  draw 
the  whole  trunk  forwards,  as  in  climbing  or  walking  on  crutches.  The 
levator  anguli  scapula?  lifts  the  upper  angle  of  the  scapula,  and  with  it  the 
entire  shoulder,  and  the  rhomboidei  carry  the  scapula  and  shoulder  up- 
wards and  backwards. 

In  examining  the  following  table,  the  student  will  observe  the  constant 
recurrence  of  the  numbers/bur  in  the  origin  and  insertion  of  the  muscles. 
Sometimes  the  four  occurs  at  the  top  or  bottom  of  a  region  of  the  spine, 
and  frequently  includes  a  part  of  two  regions,  and  takes  two  from  each, 
as  in  the  case  of  the  serrati.  Again,  he  will  perceive  that  the  muscles  of 
the  upper  half  of  the  table  take  their  origin  from  spinous  processes,  and 
pass  outwards  to  transverse,  whereas  the  lower  half  arise  mostly  from 
transverse  processes.  To  the  student,  t  ,en,  we  commit  these  reflections, 
and  leave  it  to  the  peculiar  tenor  of  his  own  mind  to  make  such  arrange- 
ments as  will  be  best  retained  by  his  memory. 

The  serrati  are  respiratory  muscles  acting  in  opposition  to  each  other, 
the  serratus  posticus  superior  drawing  the  ribs  upwards,  and  thereby  ex- 
panding the  chest ;  and  the  inferior  drawing  the  lower  ribs  downwards 
and  diminishing  the  cavity  of  the  chest.  The  former  is  an  inspiratory, 
the  latter  an  expiratory  muscle.  The  splenii  muscles  of  one  side  draw 
the  vertebral  column  backwards  and  to  one  side,  and  rotate  the  head  to- 
wards the  corresponding  shoulder.  The  muscles  of  opposite  sides,  acting 
together,  will  draw  the  head  directly  backwards.  They  are  the  natural 
antagonists  of  the  sterno-mastoid  muscles. 

The  sacro-lumbalis  with  its  accessory  muscle,  the  longissimus  dorsi,  and 
spinalis  dorsi,  are  known  by  the  general  term  of  erectores  spina,  which 
sufficiently  expresses  their  action.  They  keep  the  spine  supported  in  the 
vertical  position  by  their  broad  origin  from  below,  and  by  means  of  thei; 


ORIGIN. 

Layers. 

Spinous  Processes. 

Transverse  Pro- 
cesses. 

Ribs. 

Additional. 

1st  Layer. 

» 

last  cervical, 

I    . 

5 

occipital  bone  and? 

Latissimus  dorsi    .  < 

2d  Layer. 
Levator  anguli  sea-) 

12  dorsal 
6  lower  dorsal, 
5  lumbar 

3 

d 

3  lower 

ligamentum  nuchae  5 
sacrum  and  ilium  . 

pulse    ....    J 

Rhomboideus   mi-    ( 

lig.  rmchae  and 

1  . 

nor     .    .    .    .      ( 

last  cervical 

5 

3d  Layer. 
Serratus  posticus      S 

lig.  nuchae, 

I. 

superior      .     '     •( 
Serratus  posticus      < 

2  upper  dorsal 
2  lower  dorsal, 

5 

inferior       .     .    .  ( 
Splenius  capitis      .  S 

2  upper  lumbar 
lig.  nuchaa, 
last  cervical, 

5  *     *     * 

Splenius  colli     .    .  j 
4tA  Layer. 

6  upper  dorsal 

r  •  ' 

sacrum  and  ilium  . 

Accessorius  ad  sa-) 

.  5 

angles  of 

}.        .        .        . 

cro-lumbalem    .  3 

I 

6  lower 
•        5 

sacrum  and  lumbar  ? 

2  lower  dorsal, 

}  '     '      ' 

I 

vertebrae       .       5 

Cervicalis  ascendens 

2  upper  lumbar 

3d,  4th,  5th, 

angles  of 
4  upper 

i  '..'.: 

'   | 

and  6th  dorsal 
4  upper  dorsal, 

3  '      ' 

.  s 

4  lower  cervical 
4  upper  dorsal, 

I 

5th  Layer. 

•  I 

4  lower  cervical 

Rectus  posticus  ma-  7 

jor     .     .     .    .    .5 

Rectus  posticus  mi-  ? 

nor    5 

6th  Layer. 

from  sacrum  to 

'  1 

3d  cervical 
last  cervical  and 

5 
* 

eleven  dorsal 

Cervical  .iiHi    ? 

lumbar      .  3 

cervical  and 

I. 

.  ^ 

lumbar 

3 

OF    THE    MUSCLES    OF   THE   BACK. 


209 


INSERTION. 

Spinous  Processes. 

Transverse 

Processes. 

Ribs. 

Additional. 

. 

•         •         • 

•         •         • 

•         •         •         •      s 

•        •         •        •      s 

clavicle  and  spine  of 
the  scapula, 
posterior  bicipital  ridge 
of  the  humerus. 

*                  •                  »                  • 

•         •         • 

•           •           •           •        \ 

angle  and  base  of  the 
scapula. 

»                  *                  •                  • 

•         •         • 

•           •           •           • 

base  of  the  scapula. 

•                  •                  •                  • 

•         •         • 

.     .     .     . 

base  of  the  scapula.      ( 

*                  •                   •                  * 

•         •         • 

2d,  3d,  4th,  and  5th. 

. 

•         •         • 

4  lower  ribs. 

•                  •                   •                  « 

4  upper  cervical 

'    '    '    -1 

occipital  and  mastoid 
portion  of  temporal 
bone. 

•                  •                   •                  • 

•       •       • 

angles  of  6  lower. 

«                   »                   •                  • 

•       •       • 

angles  of  6  upper. 

•                  •                   *                  • 

•  •  •  \ 

all  the  ribs  between  the 
tubercles  and  angles. 

6  upper  dorsal. 

•       •       •       * 

4  lower  cervical. 

•       •       »       • 

4  lower  cervical. 

•       •       •       • 

•       •       • 

•       •       •       « 

mastoid  process. 

.    .    .    . 

••       «       • 

•        •        •        •     s 

occipital  bone  between 
the  curved  lines. 

(4  upper  dorsal, 
>     2  lower  cervical. 
1  4  upper  cervical, 
\    except  atlas. 

•       •       • 

•        •        •        • 

occipital  bone. 

•        •        •        • 

•       •       • 

•            •            •            v 

occipital  bone. 

•        •        •        • 

•        •        •        • 

•       •       t 

atlas. 
•       •       • 

•            •            •            • 
«            •            •            • 

occipital  bone, 
occipital  bone. 

(from  last  lumbar  to 
\    axis. 

cervical. 

•    •    •  { 

all  the  ribs  between  the 
tubercles  and  angles. 

cervical  and  lumbar. 

.       .       .       . 

(  cervical  and 
(      lumbar. 

18 


210  MUSCLES    OF   THE    THORAX. 

iisertion,  by  distinct  tendons,  into  the  ribs  and  spinous  processes.  Being 
made  up  of  a  number  of  distinct  fasciculi,  which  alternate  in  their  actions, 
the  spine  is  kept  erect  without  fatigue,  even  when  they  have  to  counter- 
balance a  corpulent  abdominal  development.  The  continuations  upwards 
of  these  muscles  into  the  neck  preserve  the  steadiness  and  uprightness  of 
that  region.  When  the  muscles  of  one  side  act  alone,  the  neck  is  rotated 
upon  its  axis.  The  complexus,  by  being  attached  to  the  occipital  bone, 
draws  the  head  backwards,  and  counteracts  the  muscles  on  the  anterior 
part  of  the  neck.  It  assists  also  in  the  rotation  of  the  head. 

The  semi-spinales  and  multiftdus  spince  muscles  act  directly  on  the  ver- 
tebrae, and  contribute  to  the  general  action  of  supporting  the  vertebral 
column  erect. 

The  four  little  muscles  situated  between  the  occiput  and  the  two  first 
vertebrae,  effect  the  various  movements  between  these  bones ;  the  recti 
producing  the  antero-posterior  actions,  and  the  obliqui  the  rotatory  mo- 
tions of  the  atlas  on  the  axis. 

The  actions  of  the  remaining  muscles  of  the  spine,  the  supra  and  inter- 
spinales  and  inter-transversales,  are  expressed  in  their  names.  They  ap- 
proximate their  attachments  and  assist  the  more  powerful  muscles  in  pre- 
serving the  erect  position  of  the  body. 

The  levatores  costarum  raise  the  posterior  parts  of  the  ribs,  and  are 
probably  more  serviceable  in  preserving  the  articulation  of  the  ribs  from 
dislocation,  than  in  raising  them  in  inspiration. 

\ 

MUSCLES    OF    THE    THORAX. 

The  principal  muscles  situated  upon  the  thorax  belong  in  their  actions 
to  the  upper  extremity,  with  which  they  will  be  described.  They  are  the 
pectoralis  major  and  minor,  subclavius  and  serratus  magnus.  The  true 
thoracic  muscles  are  few  in  number,  and  appertain  exclusively  to  the  ac- 
tions of  the  ribs ;  they  are,  the — 

Intercostales  externi, 
Intercostales  interni, 
Triangularis  sterni. 

The  intercostal  muscles  are  two  planes  of  muscular  and  tendinous 
fibres  directed  obliquely  between  the  adjacent  ribs  and  closing  the  inter- 
costal spaces.  They  are  seen  partially  upon  the  removal  of  the  pectoral 
muscles,  or  upon  the  inner  surface  of  the  chest.  The  triangularis  sterni 
is  within  the  chest,  and  requires  the  removal  of  the  anterior  part  of  the 
thorax  to  bring  it  into  view. 

The  INTERCOSTALES  EXTERNI,  eleven  on  each  side,  commence  poste- 
rioily  at  the  tubercles  of  the  ribs,  and  advance  forwards  to  the  costal  car- 
tilages, where  they  terminate  in  a  thin  aponeurosis,  which  is  continued 
onwards  to  the  sternum.  Their  fibres  are  directed  obliquely  downwards 
and  inwards,  pursuing  the  same  line  with  those  of  the  external  oblique 
muscle  of  the  abdomen.  They  are  thicker  than  the  internal  intercostals. 

The  INTERCOSTALES  INTERNI,  also  eleven  on  each  side,  commence  ante- 
riorly at  the  sternum,  and  extend  backwards  as  far  as  the  angles  of  the 
ribs,  whence  they  are  prolonged  to  the  vertebral  column  by  a  thin  apo- 
neurosis. Their  fibres  are  directed  obliquely  downwards  and  backwards, 
and  correspond  in  direction  with  those  of  the  internal  oblique  muscle  of 


MUSCLES    OF   THE    ABDOMEN.  211 

the  abdomen.  The  two  muscles  cross  each  other  in  the  direction  of  their 
fibres. 

In  structure  the  intercostal  muscles  consist  of  an  admixture  of  muscular 
and  tendinous  fibres.  They  arise  from  the  two  lips  of  the  lower  border 
of  the  ribs,  the  external  from  the  outer  lip,  the  internal  from  the  inner, 
and  are  inserted  into  the  upper  border. 

Relations. — The  external  intercostals,  by  their  external  surface,  with  the 
muscles  which  immediately  invest  the  chest,  viz.  the  pectoralis  major  and 
minor,  the  serratus  magnus,  serratus  posticus  superior  and  inferior,  scalenus 
posticus ;  sacro-lumbalis,  and  longissimus  dorsi,  with  their  continuations, 
the  cervicalis  ascendens  and  transversalis  colli ;  the  levatores  costarum, 
and  the  obliquus  externus  abdominis.  By  their  internal  surface  with  the 
internal  intercostals,  the  intercostal  vessels  and  nerves,  and  a  thin  aponeu- 
rosis,  and  posteriorly  with  the  pleura.  The  internal  intercostals,  by  their 
external  surface  with  the  external  intercostals,  and  intercostal  vessels  and 
nerves ;  by  their  internal  surface  with  the  pleura  costalis,  the  triangularis 
sterni  and  diaphragm. 

Connected  with  the  internal  intercostals  are  a  variable  number  of  mus- 
cular fasciculi,  which  pass  from  the  inner  surface  of  one  rib  near  its  middle 
to  the  next  or  next  but  one  below ;  these  are  the  subcostal,  or  more  cor- 
rectly the  infracostal  muscles. 

The  TRIANGULARIS  STERNI,  situated  upon  the  inner  wall  of  the  front  of 
the  chest,  arises  by  a  thin  aponeurosis  from  the  side  of  the  sternum,  ensi- 
form  cartilage,  and  sternal  extremities  of  the  costal  cartilages ;  and  is  in- 
serted by  fleshy  digitations  into  the  cartilages  of  the  third,  fourth,  fifth  and 
sixth  ribs,  and  often  into  that  of  the  second. 

Relations. — By  its  external  surface  with  the  sternum,  the  ensiform  carti- 
lage, the  costal  cartilages,  internal  intercostal  muscles,  and  internal  mam- 
mary vessels.  By  its  internal  surface  with  the  pleura  costalis,  the  areolar 
tissue  of  the  anterior  mediastinum  and  the  diaphragm.  The  lower  fibres 
of  the  triangularis  sterni  are  continuous  with  those  of  the  diaphragm. 

Actions. — The  intercostal  muscles  raise  the  ribs  when  they  act  from 
above,  and  depress  them  when  they  take  their  fixed  point  from  below. 
They  are,  therefore,  both  inspiratory  and  expiratory  muscles.  The  trian- 
gularis sterni  draws  down  the  costal  cartilages,  and  is,  therefore,  an  expi- 
ratory muscle. 

MUSCLES    OF    THE  ABDOMEN. 

The  muscles  of  this  region  are,  the — 

Obliquus  externus  (descendens), 

Obliquus  internus  (ascendens), 

Cremaster, 

Transversalis, 

Rectus, 

Pyramidalis, 

Quadratus  lumborum, 

Psoas  parvus, 

Diaphragm. 

Dissection. — The  dissection  of  the  abdominal  muscles  is  to  be  commenced 
by  making  three  incisions : — The  first,  vertical,  in  the  middle  line,  from 
over  the  lower  part  of  the  sternum  to  the  pubes ;  the  second  oblique,  frorr. 


212  MUSCLES   OF   THE   ABDOMEN. 

the  umbilicus,  upwards  and  outwards,  to  the  outer  side  of  the  chest,  as 
high  as  the  fifth  or  sixth  rib  ;  and  the  third,  oblique,  from  the  umbilicus, 
downwards  and  outwards,  to  the  middle  of  the  crest  of  the  ilium.  The 
three  flaps  included  by  these  incisions  should  then  be  dissected  back  in 
the  direction  of  the  fibres  of  the  external  oblique  muscle,  beginning  at  the 
angle  of  each.  The  integument  and  superficial  fascia  should  be  dissected 
off'  together  so  as  to  expose  the  fibres  of  the  muscle  at  once. 

If  the  external  oblique  muscle  be  dissected  on  both  sides,  a  white  ten- 
dinous line  will  be  seen  along  the  middle  of  the  abdomen,  extending  from 
the  ensiform  cartilage  to  the  os  pubis ;  this  is  the  linea  alba.  A  little  ex- 
ternal to  it,  on  each  side,  two  curved  lines  will  be  observed  extending 
from  the  sides  of  the  chest  to  the  os  pubis,  and  bounding  the  recti  muscles : 
these  are  the  linea  semilunares.  Some  transverse  lines,  linete  transversce, 
three  or  four  in  number,  connect  the  linese  semilunares  with  the  linea 
alba. 

The  EXTERNAL  OBLIQUE  MUSCLE  (obliquus  externus  abdominis  descendens) 
is  the  external  flat  muscle  of  the  abdomen.  Its  name  is  derived  from  the 
obliquity  of  its  direction,  and  the  descending  course  of  its  fibres.  It 
arises  by  fleshy  digitations  from  the  external  surface  of  the  eight  inferior 
ribs ;  the  five  upper  digitations  being  received  between  corresponding  pro- 
cesses of  the  serratus  magnus,  and  the  three  lower  of  the  latissimus  dorsi. 
Soon  after  its  origin  it  spreads  out  into  a  broad  aponeurosis,  wThich  is  in- 
serted into  the  outer  lip  of  the  crest  of  the  ilium  for  one  half  its  length,  the 
anterior  superior  spinous  process  of  the  ilium,  spine  of  the  os  pubis,  pecti- 
neal  line,  front  of  the  os  pubis,  and  linea  alba. 

The  lower  border  of  the  aponeurosis,  which  is  stretched  between  the 
anterior  superior  spinous  process  of  the  ilium  and  the  spine  of  the  os  pubis, 
is  rounded  from  being  folded  inwards,  and  forms  Pouparfs  ligament;  the 
insertion  into  the  pectineal  line  is  Gimbernat: 's  ligament. 

Just  above  the  crest  of  the  os  pubis  is  the  external  abdominal  ring,  a 
triangular  opening  formed  by  the  separation  of  the  fibres  of  the  aponeuro- 
sis of  the  external  oblique.  It  is  oblique  in  its  direction,  and  corresponds 
with  the  course  of  the  fibres  of  the  aponeurosis.  It  is  bounded  below  by 
the  crest  of  the  os  pubis ;  on  either  side  by  the  borders  of  the  aponeurosis, 
which  are  called  pillars;  and  above  by  some  curved  fibres  (inter-colum- 
nar), which  originate  from  Poupart's  ligament,  and  cross  the  upper  angle 
of  the  ring  so  as  to  give  it  strength.  The  external  pillar,  which  is  at  the 
same  time  inferior  from  the  obliquity  of  the  opening,  is  inserted  into  the 
spine  of  the  os  pubis ;  the  internal  or  superior  pillar  forms  an  interlacement 
with  its  fellow  of  the  opposite  side  over  the  front  of  the  symphysis  pubis. 
The  external  abdominal  ring  gives  passage  to  the  spermatic  cord  in  the 
male  and  round  ligament  in  the  female:  they  are  both  invested  in  their 
passage  through  it  by  a  thin  fascia  derived  from  the  edges  of  the  ring,  and 
called  inter-columnar  fascia,  or  fascia  spermatica. 

The  pouch  of  inguinal  hernia,  in  passing  through  this  opening,  receives 
the  inter-columnar  fascia,  as  one  of  its  coverings. 

Relations. — By  its  external  surface  with  the  superficial  fascia  and  inte- 
gument, and  with  the  cutaneous  vessels  and  nerves,  particularly  the  super- 
ficial epigastric  and  superficial  circumflexa  ilii  vessels.  It  is  generally 
overlapped  posteriorly  by  the  latissimus  dorsi.  By  its  internal  surface 
with  the  internal  oblique,  the  lower  part  of  the  eight  inferior  ribs  and  in- 
tercostal muscles,  the  cremaster,  the  spermatic  cord  in  the  male,  and  the 


MUSCLES    OF    THE   ABDOMEN. 


213 


round  ligament  in  the  female.     The  upper  border  of  the  external  oblique 
is  continuous  with  the  pectoralis  major. 

The  external  oblique  is  now  to  be  removed  by  making  an  incision 
across  the  ribs,  just  below  its  origin,  to  its  posterior  border ;  and  another 
along  Poupart's  ligament  and  the  crest  of  the  ilium.  Poupart's  ligamen* 

Fig.  116.* 


*  The  muscles  of  the  anterior  aspect  of  the  trunk ;  on  the  left  side  the  superficial 
'.ayer  is  seen,  and  on  the  right  the  deeper  layer.  1.  The  pectoralis  major  muscle.  2. 
The  deltoid ;  the  interval  between  these  muscles  lodges  the  cephalic  vein.  3.  The  an 
terior  border  of  the  latissimus  dorsi.  4.  The  serrations  of  the  serratus  magnus.  5.  The 
subclavius  muscle  of  the  right  side.  6.  The  pectoralis  minor.  7.  The  coracho-brachia- 
lis  muscle.  8.  The  upper  part  of  the  biceps  muscle,  showing  its  two  heads.  9.  Tho 
coracoid  process  of  the  scapula.  10.  The  serratus  magnus  of  the  right  side.  11.  The 
external  intercostal  muscle  of  the  fifth  intercostal  space.  12.  The  external  oblique 
muscle.  13.  Its  aponeurosis;  the  median  line  to  the  right  of  this  number  is  the  linea 
alba;  the  flexuous  line  to  its  left  is  the  linea  semilunaris;  and  the  transverse  lines 
above  and  below  the  number,  the  linese  transversse.  14.  Poupart's  ligament.  15.  The 
external  abdominal  ring;  the  margin  above  the  ring  is  the  superior  or  internal  pillar; 
the  margin  below  the  ring,  the  inferior  or  external  pillar;  the  curved  intercolumnar 
fibres  are  seen  proceeding  upwards  from  Poupart's  ligament  to  strengthen  the  ring. 
The  numbers  14  and  15  are  situated  upon  the  fascia  lata  of  the  thigh  ;  the  opening  im- 
mediately to  the  right  of  15  is  the  saphenous  opening.  16.  The  rectus  muscle  of  the 
right  side  brought  into  view  by  the  removal  of  the  anterior  segment  of  its  sheath  :  *  the 
posterior  segment  of  its  sheath  with  the  divided  edge  of  the  anterior  segment.  17 
The  pyramidalis  muscle.  18.  The  internal  oblique  muscle.  19.  The  conjoined  ten 
don  of  the  internal  oblique  and  transversalis  descending  behind  Poupart's  ligament 
to  the  pectineal  line.  20.  The  arch  formed  between  the  lower  curved  border  of  the 
interna1  oblique  muscle  and  Poupart's  ligament,  it  is  beneath  this  arch  that  the  sperm 
aiic  cord  and  hernia  pass. 


214  MUSCLES    OF   THE    ABDOMEN. 

should  be  left  entire,  as  it  gives  attachment  to  the  next  muscles.  The 
muscle  may  then  be  turned  forwards  towards  the  linea  alba,  or  removed 
altogether. 

The  INTERNAL  OBLIQUE  MUSCLE  (obliquus  internus  abdominis  ascendens] 
is  the  middle  flat  muscle  of  the  abdomen.  It  arises  from  the  outer  half 
of  Poupart's  ligament,  from  the  middle  of  the  crest  of  the  ilium  for  two- 
thirds  of  its  length,  and  by  a  thin  aponeurosis  from  the  spinous  processes 
of  the  lumbar  vertebrae.  Its  fibres  diverge  from  their  origin,  so  that  those 
from  Poupart's  ligament  curve  downwards,  those  from  the  anterior  part 
of  the  crest  of  the  ilium  pass  transversely,  and  the  rest  ascend  obliquely. 
The  muscle  is  inserted  into  the  pectineal  line  and  crest  of  the  os  pubis, 
linea  alba,  and  lower  borders  of  the  five  inferior  ribs. 

Along  the  upper  three-fourths  of  the  linea  semilunaris,  the  aponeurosis 
of  the  internal  oblique  separates  into  two  lamellae,  which  pass  one  in  front 
and  the  other  behind  the  rectus  muscle  to  the  linea  alba,  where  they  are 
inserted  ;  along  the  lower  fourth,  the  aponeurosis  passes  altogether  in  front 
of  the  rectus  without  separation.  The  two  layers,  which  thus  enclose  the 
rectus,  form  for  it  a  partial  sheath. 

The  lowest  fibres  of  the  internal  oblique  are  inserted  into  the  pectineal 
line  of  the  os  pubis  in  common  with  those  of  the  transversalis  muscle. 
Hence  the  tendon  of  this  insertion  is  called  the  conjoined  tendon  of  the  in- 
ternal oblique  and  transversalis.  This  structure  corresponds  with  the 
external  abdominal  ring,  and  forms  a  protection  to  what  would  otherwise 
be  a  weak  point  in  the  abdomen.  Sometimes  the  tendon  is  insufficient  to 
resist  the  pressure  from  within,  and  becomes  forced  through  the  external 
ring  ;  it  then  forms  the  distinctive  covering  of  direct  inguinal  hernia. 

The  spermatic  cord  passes  beneath  the  arched  border  of  the  internal 
oblique  muscle,  between  it  and  Poupart's  ligament.  During  its  passage 
some  fibres  are  given  off  from  the  lower  border  of  the  muscle,  which  ac- 
company the  cord  downwards  to  the  testicle,  and  form  loops  around  it : 
this  is  the  cremaster  muscle.  In  the  descent  of  oblique  inguinal  hernia, 
which  travels  the  same  course  with  the  spermatic  cord,  the  cremaster 
muscle  forms  one  of  its  coverings. 

The  CREMASTER,  considered  as  a  distinct  muscle,  arises  from  the  mid- 
dle of  Poupart's  ligament,  and  forms  a  series  of  loops  upon  the  spermatic 
cord.  A  few  of  its  fibres  are  inserted  into  the  tunica  vaginalis,  the  rest 
ascend  along  the  inner  side  of  the  cord,  to  be  inserted,  with  the  conjoined 
tendon,  into  the  pectineal  line  of  the  os  pubis. 

Relations. — The  internal  oblique  is  in  relation,  by  its  external  surface, 
with  the  external  oblique,  latissimus  dorsi,  spermatic  cord,  and  external 
abdominal  ring.  By  its  internal  surface,  with  the  transversalis  muscle, 
the  fascia  transversalis,  the  internal  abdominal  ring,  and  spermatic  cord. 
By  its  lower  and  arched  border,  with  the  spermatic  cord,  forming  the 
upper  boundary  of  the  spermatic  canal. 

The  cremaster  is  in  relation,  by  its  external  surface,  with  the  aponeuro- 
sis of  the  external  oblique  and  intercolumnar  fascia ;  and  by  its  internal 
surface,  with  the  fascia  propria  of  the  spermatic  cord. 

The  internal  oblique  muscle  is  to  be  removed  by  separating  it  from  its 
attachments  to  the  ribs  above,  and  to  the  crest  of  the  ilium  and  Poupart's 
ligament  below.  It  should  be  divided  behind  by  a  vertical  incision,  ex- 
tending from  the  last  rib  to  the  crest  of  the  ilium,  as  its  lumbar  attachment 
rannot  at  present  be  examined.  The  muscle  is  then  to  be  turned  for- 


TRANSVERSALIS. 


215 


Fig.  117." 


wards.  Some  degree  of  care  A'ill  be  required  in  performing  this  dissec- 
tion, from  the  difficulty  of  distinguishing  between  this  muscle  and  the  one 
beneath.  A  thin  layer  of  cellular  tissue  is  all  that  separates  them  for  the 
greater  part  of  their  extent.  Near  the  crest  of  the  ilium,  the  circumflexa 
ilii  artery  ascends  between  the  two  muscles,  and  forms  a  valuable  guide 
to  their  separation.  Just  above  Poupart's  ligament  they  are  so  closely 
connected,  that  it  is  impossible  to  divide  them. 

The  TRANSVERSALIS  is  the  internal  flat  muscle  of  the  abdomen ;  it  is 
transverse  in  the  direction  of  its  fibres,  as  is  implied  in  its  name.  It  arises 
from  the  outer  third  of  Poupart's  ligament,  from  the  internal  lip  of  the  crest 
of  the  ilium,  its  anterior  two-thirds  ;  from  the  spinous  and  transverse  pro- 
cesses of  the  lumbar  vertebrae,  and  from  the  inner  surfaces  of  the  six  in- 
ferior ribs,  indigitating  with  the  diaphragm.  Its  lower  fibres  curve  down- 
wards, to  be  inserted,  with  the  lower  fibres  of  the  internal  oblique,  into  the 
pectineal  line,  and  form  the  conjoined  tendon.  Throughout  the  rest  of 
its  extent  it  is  inserted  into  the  crest  of  the  os  pubis  and  linea  alba.  The 
lower  fourth  of  its  aponeurosis  passes  in  front  of  the  rectus  to  the  linea 
alba ;  the  upper  three-fourths  with  the  posterior  lamella  of  the  mtern:il 
oblique,  behind  it. 

The  posterior  aponeurosis  of  the  transver- 
salis  divides  into  three  lamellae  ; — anterior, 
which  is  attached  to  the  bases  of  the  trans- 
verse processes  of  the  lumbar  vertebrae ; 
middle,  to  the  apices  of  the  transverse  pro- 
cesses ;  and  posterior,  to  the  apices  of  the 
spinous  processes.  The  anterior  and  mid- 
dle lamellae  enclose  the  quadratus  lumborum 
muscle ;  and  the  middle  and  posterior,  the 
erector  spinae.  The  union  of  the  posterior 
lamella  of  the  transversalis  with  the  poste- 
rior aponeurosis  of  the  internal  oblique, 
serratus  posticus  inferior,  and  latissimus 
dorsi,  constitutes  the  lumbar  fascia. 

Relations. — By  its  external  surface  with 
the  internal  oblique,  the  internal  surfaces 
of  the  lower  ribs,  and  internal  intercostal 
muscles.  By  its  internal  surface  with  the 
transversalis  fascia,  which  separates  it  from 
the  peritoneum,  with  the  psoas  magnus,  and 
with  the  lower  part  of  the  rectus  and  pyra- 
midalis.  The  spermatic  cord  and  oblique 
inguinal  hernia  pass  beneath  the  lower  bor- 
der, but  have  no  direct  relation  with  it. 

*  A  lateral  view  of  the  trunk  of  the  body,  showing  its  muscles,  and  particularly  the 
transversalis  abdominis.  1.  The  costal  origin  of  the  latissimus  dorsi  muscle.  2.  The 
serratus  magnus.  3.  The  upper  part  of  the  external  oblique  muscle,  divided  in  the  di- 
rection best  calculated  to  show  the  muscles  beneath,  without  interfering  with  its  indigi- 
tations  with  the  serratus  magnus.  4.  Two  of  the  external  intercostal  muscles.  5.  Two 
of  the  internal  intercostals.  6.  The  transversalis  muscle.  7.  Its  posterior  aponeurosis. 

8.  Its  anterior  aponeurosis,  forming  the  most  posterior  layer  of  the  sheath  of  the  rectus. 

9.  The  lower  part  of  the  left  rectus,  with  the  aponeurosis  of  the  transversalis  passing  in 
front.      10.  The  right  rectus  muscle.     11.     The  arched  opening  left  between  the  lower 
border  of  the  transversalis  muscle  and  Poupart's  ligament,  through  which  the  spermatic 
cord  and  hernia  pass.      12.  The  gluteus  maximus,  and  inedius,  and  tensor  vaginas  femo 
ris  muscles  invested  bv  fascia  lata. 


216  MUSCLES    OF   THE   ABDOMEN. 

To  dissect  the  rectus  muscle,  its  sheath  should  be  opened  by  a  vertical 
incision  extending  from  over  the  cartilages  of  the  lower  ribs  to  the  front 
of  the  os  pubis.  The  sheath  may  then  be  dissected  off  and  turned  to  either 
side ;  this  is  easily  done  excepting  at  the  lineae  transversae,  where  a  close 
adhesion  subsists  between  the  muscle  and  the  external  boundary  of  the 
sheath.  The  sheath  contains  the  rectus  and  pyramidalis  muscle. 

The  RECTUS  MUSCLE  arises  by  a  flattened  tendon  from  the  crest  of  the 
os  pubis,  and  is  inserted  into  the  cartilages  of  the  fifth,  sixth,  and  seventh 
ribs.  It  is  traversed  by  several  tendinous  zigzag  intersections,  called 
lines  transversae.  One  of  these  is  usually  situated  at  the  umbilicus,  two 
above  that  point,  and  sometimes  one  below.  They  are  vestiges  of  the 
abdominal  ribs  of  reptiles,  and  very  rarely  extend  completely  through  the 
muscle. 

Relations. — By  its  external  surface  with  the  anterior  lamella  of  the  apo- 
neurosis  of  the  internal  oblique,  below  with  the  aponeurosis  of  the  trans- 
versalis,  and  pyramidalis.  By  its  internal  surface  with  the  ensiform  carti- 
lages of  the  fifth,  sixth,  seventh,  eighth  and  ninth  ribs,  with  the  posterior 
lamella  of  the  internal  oblique,  the  peritoneum,  and  the  epigastric  artery 
and  veins. 

The  PYRAMIDALIS  MUSCLE  arises  from  the  crest  of  the  os  pubis  in  front 
of  the  rectus,  and  is  inserted  into  the  linea  alba  at  about  midway  between 
the  umbilicus  and  the  os  pubis.  It  is  enclosed  in  the  same  sheath  with 
the  rectus,  and  rests  against  the  lower  part  of  that  muscle.  This  muscle 
is  sometimes  wanting. 

The  rectus  may  now  be  divided  across  the  middle,  and  the  two  ends 
drawn  aside  for  the  purpose  of  examining  the  mode  of  formation  of  its 
sheath. 

The  sheath  of  the  rectus  is  formed  in  front  for  the  upper  three-fourths  of 
its  extent,  by  the  aponeurosis  of  the  external  oblique  and  the  anterior  la- 
mella of  the  internal  oblique,  and  behind  by  the  posterior  lamella  of  the 
internal  oblique  and  the  aponeurosis  of  the  transversalis.  At  the  com- 
mencement of  the  lower  fourth,  the  posterior  wall  of  the  sheath  terminates 
in  a  thin  curved  margin,  the  aponeurosis  of  the  three  muscles  passing  alto- 
gether in  front  of  the  rectus. 

The  next  two  muscles  can  be  examined  only  when  the  viscera  of  the 
abdomen  are  removed.  To  see  the  quadratus  lumborum,  it  is  also  neces- 
sary to  divide  and  draw  aside  the  psoas  muscle  and  the  anterior  lamella 
of  the  aponeurosis  of  the  transversalis. 

The  QUADRATUS  LUMBORUM  muscle  is  concealed  from  view  by  the  an- 
terior lamella  of  the  aponeurosis  of  the  transversalis  muscle,  which  is  in- 
serted into  the  bases  of  the  transverse  processes  of  the  lumbar  vertebrae. 
When  this  lamella  is  divided,  the  muscle  will  be  seen  arising  from  the  last 
rib,  and  from  the  transverse  processes  of  the  four  upper  lumbar  vertebrae. 
It  is  inserted  into  the  crest  of  the  ilium  and  ilio-lumbar  ligament.  If  the 
muscle  be  cut  across  or  removed,  the  middle  lamella  of  the  transversalis 
will  be  seen  attached  to  the  apices  of  the  transverse  processes ;  the  qua- 
dratus being  enclosed  between  the  two  lamellse  as  in  a  sheath. 

Relations. — Enclosed  in  the  sheath  formed  by  the  transversalis  muscle, 
it  is  in  relation  in  front,  with  the  kidney,  the  colon,  the  psoas  magnus  and 
the  diaphragm.  Behind,  but  also  separated  by  a  sheath,  with  the  erector 
spinse. 

The  PSOAS  PARVUS  arises  from  the  tendinous  arches  and  intervertebral 


DIAPHRAGM.  217 

substance  of  the  last  dorsal  and  first  lumbar  vertebra,  and  terminates  in  a 
long  slender  tendon  which  expands  inferiorly  and  is  inserted  into  the  ilio- 
pectineal  line  and  eminence.  The  tendon  is  continuous  by  its  outer  bor- 
der with  the  iliac  fascia. 

Relations. — It  rests  upon  the  psoas  magnus,  and  is  covered  in  by  the 
peritoneum ;  superiorly  it  passes  beneath  the  ligamentum  arcuatum  of  the 
diaphragm.  It  is  occasionally  wanting. 

DIAPHRAGM. — To  obtain  a  good  view  of  this  important  inspiratory 
muscle,  the  peritoneum  should  be  dissected  from  its  under  surface.  It  is 
the  muscular  septum  between  the  thorax  and  abdomen,  and  is  composed 
of  two  portions,  a  greater  and  a  lesser  muscle.  The  greater  muscle  arises 
from  the  ensiform  cartilage ;  from  the  inner  surfaces  of  the  six  inferior 
ribs,  indigitating  with  the  transversalis  ;  and  from  the  ligamentum  arcua- 
tum externum  and  internum.  From  these  points,  which  form  the  internal 
circumference  of  the  trunk,  the  fibres  converge  and  are  inserted  into  the 
central  tendon. 

The  ligamentum  arcuatum  externum  is  the  upper  border  of  the  anterior 
lamella  of  the  aponeurosis  of  the  transversalis :  it  arches  across  the  origin 
of  the  quadratus  lumborum  muscle,  and  is  attached  by  one  extremity  to 
the  base  of  the  transverse  process  of  the  first  lumbar  vertebra,  and  by  the 
other  to  the  apex  and  lower  margin  of  the  last  rib. 

The  ligamentum  arcuatum  internum,  or  proprium,  is  a  tendinous  arch 
thrown  across  the  psoas  magnus  muscle  as  it  emerges  from  the  chest.  It 
is  attached  by  one  extremity  to  the  base  of  the  transverse  process  of  the 
first  lumbar  vertebra,  and  by  the  other  is  continuous  with  the  tendon  of 
the  lesser  muscle  opposite  the  body  of  the  second. 

The  tendinous  centre  of  the  diaphragm  is  shaped  like  a  trefoil  leaf,  of 
which  the  central  leaflet  points  to  the  ensiform  cartilage,  and  is  the  largest ; 
the  lateral  leaflets,  right  and  left,  occupy  the  corresponding  portions  of  the 
muscle ;  the  right  being  the  larger  and  more  rounded,  and  the  left  smaller 
and  lengthened  in  its  form. 

Between  the  sides  of  the  ensiform  cartilage  and  the  cartilages  of  the 
adjoining  ribs,  is  a  small  triangular  space  where  the  muscular  fibres  of  the 
diaphragm  are  deficient.  This  space  is  closed  only  by  peritoneum  on  the 
side  of  the  abdomen,  and  by  pleura  within  the  chest.  It  is  therefore  a 
weak  point,  and  a  portion  of  the  contents  of  the  abdomen  might,  by  vio- 
lent exertion,  be  forced  through  it,  producing  phrenic,  or  diaphragmatic 
hernia. 

The  lesser  muscle  of  the  diaphragm  takes  its  origin  from  the  bodies  of 
the  lumbar  vertebrae  by  two  tendons.  The  right,  larger  and  longer  than 
the  left,  arises  from  the  anterior  surface  of  the  bodies  of  the  second,  third, 
and  fourth  vertebras  ;  and  the  left  from  the  side  of  the  second  and  third. 
The  tendons  form  two  large  fleshy  bellies  (crura),  which  ascend  to  be  in- 
serted into  the  central  tendon.  The  inner  fasciculi  of  the  two  crura  cross 
each  other  in  front  of  the  aorta,  and  again  diverge  to  surround  the  oeso- 
phagus, so  as  to  present  the  appearance  of  a  figure  of  eight.  The  ante 
rior  fasciculus  of  the  decussation  is  formed  by  the  right  crus. 

The  openings  in  the  diaphragm  are  three :  one,  quadrilateral,  in  the 
tendinous  centre,  at  the  union  of  the  right  and  middle  leaflets,  for  the 
passage  of  the  inferior  vena  cava ;  a  muscular  opening  of  an  elliptic  shape 
formed  by  the  two  crura,  for  the  transmission  of  the  oesophagus  and  pneu- 
mogastric  nerves  ;  and  a  third,  the  aortic,  which  is  formed  by  a  tendinous 
19 


218 


MUSCLES    QrF   THE    ABDOMEN. 


Fig- 118-*  arch  thrown  from  the  tendon 

of  one  crus  to  that  of  the  other, 
beneath  which  pass  the  aorta, 
the  right  vena  azygos,  and 
thoracic  duct.  The  great 
splanchnic  nerves  pass  through 
openings  in  the  lesser  muscle 
on  each  side,  and  the  lesser 
splanchnic  nerves  through  the 
fibres  which  arise  from  the 
ligamentum  arcuatum  inter- 
num. 

Relations. — By  its  superior 
surface  with  the  pleurae,  the 
pericardium,  the  heart,  and 
the  lungs.  By  its  inferior 
surface  with  the  peritoneum; 
on  the  left  with  the  stomach 
and  spleen  ;  on  the  right  with 

the  convexity  of  the  liver ;  and  behind  with  the  kidneys,  the  supra-renal 
capsules,  the  duodenum,  and  the  solar  plexus.  By  its  circumference  with 
the  ribs  and  intercostal  muscles,  and  with  the  vertebral  column. 

Actions. — The  external  oblique  muscle,  acting  singly,  would  draw  the 
thorax  towards  the  pelvis,  and  twist  the  body  to  the  opposite  side.  Both 
muscles,  acting  together,  would  flex  the  thorax  directly  on  the  pelvis. 
The  internal  oblique  of  one  side  draws  the  chest  downwards  and  outwards: 
both  together  bend  it  directly  forwards.  Either  transversalis  muscle,  act- 
ing singly,  will  diminish  the  size  of  the  abdomen  on  its  own  side,  and  both 
together  will  constrict  the  entire  cylinder  of  the  cavity.  The  recti  muscles, 
assisted  by  the  pyramid  ales,  flex  the  thorax  upon  the  chest,  and,  through 
the  medium  of  the  linese  transversse,  are  enabled  to  act  when  their  sheath 
is  curved  inwards  by  the  action  of  the  transversales.  The  pyramidales 
are  tensors  of  the  linea  alba.  The  abdominal  are  expiratory  muscles,  and 
the  chief  agents  of  expulsion  ;  by  their  action  the  foetus  is  expelled  from 
the  uterus,  the  urine  from  the  bladder,  the  faeces  from  the  rectum,  the  bile 
from  the  gall-bladder,  the  ingesta  from  the  stomach  and  bowels  in  vomit- 
ing, and  the  mucous  and  irritating  substances  from  the  bronchial  tubes, 

*  The  under  or  abdominal  side  of  the  diaphragm.  1,  2,  3.  The  greater  muscle ;  the 
figure  1  rests  upon  the  central  leaflet  of  the  tendinous  centre  ;  the  number  2  on  the  left 
or  smallest  leaflet;  and  number  3  on  the  right  leaflet.  4.  The  thin  fasciculus  which 
arises  from  the  ensiform  cartilage  ;  a  small  triangular  space  is  left  on  either  side  of  this 
fasciculus,  wmch  is  closed  only  by  the  serous  membranes  of  the  abdomen  and  chest. 
5.  The  ligamentum  arcuatum  externum  of  the  left  side.  6.  The  ligamentum  arcuatum 
internum.  7.  A  small  arched  opening  occasionally  found,  through  which  the  lesser 
splanchnic  nerve  passes.  8.  The  right  or  larger  tendon  of  the  lesser  muscle  ;  a  mus- 
cular fasciculus  from  this  tendon  curves  to  the  left  side  of  the  greater  muscle  between 
the  resophageal  and  aortic  openings.  9.  The  fourth  lumbar  vertebra.  10.  The  left  or 
shorter  tendon  of  the  lesser  muscle.  11.  The  aortic  opening  occupied  by  the  aorta, 
which  is  cut  short  off.  12.  A  portion  of  the  oesophagus  issuing  through  the  ossophageal 
opening ;  in  this  figure  the  cesophageal  opening  is  tendinous  at  its  anterior  part,  a  struc- 
ture which  is  not  uncommon.  13.  The  opening  for  the  inferior  vena  cava,  in  the  ten- 
dinous centre  of  tl»e  diaphragm.  14.  The  psoas  magnus  muscle  passing  beneath  the 
ligamentum  arcuatum  internum ;  it  has  been  removed  on  the  opposite  side  to  show  the 
arch  more  distinctly.  15.  The  quadratus  lumborum  passing  beneath  the  ligamentum 
arcuatum  c-xternum  ,  this  muscle  has  also  been  removed  on  the  left  side. 


MUSCLES  OF  THE  PERINEUM.  219 

trachea,  and  nasal  passages,  during  coughing  and  sneezing.  To  produce 
these  efforts  they  all  act  together.  Their  violent  and  continued  action 
produces  hernia ;  and,  acting  spasmodically,  they  may  occasion  rupture 
of  the  viscera.  The  quadratus  lumborum  draws  the  last  rib  downwards, 
and  is  an  expiratory  muscle  ;  it  also  serves  to  bend  the  vertebral  column 
to  one  or  the  other  side.  The  psoas  parvus  is  a  tensor  of  the  iliac  fascia, 
and,  taking  its  fixed  origin  from  below,  it  may  assist  in  flexing  the  verte- 
bral column  forwards.  The  diaphragm  is  an  inspiratory  muscle,  and  the 
sole  agent  in  tranquil  inspiration.  When  in  action,  the  muscle  is  drawn 
downwards,  its  plane  being  rendered  oblique  from  the  level  of  the  ensi- 
form  cartilage,  to  that  of  the  upper  lumbar  vertebra.  During  relaxation 
it  is  convex,  and  encroaches  considerably  on  the  cavity  of  the  chest,  par- 
ticularly at  the  sides,  where  it  corresponds  with  the  lungs.  It  assists  the 
abdominal  muscles  powerfully  in  expulsion,  every  act  of  that  kind  being 
preceded  or  accompanied  by  a  deep  inspiration.  Spasmodic  action  of  the 
diaphragm  produces  hiccough  and  sobbing,  and  its  rapid  alternation  of 
contraction  and  relaxation,  combined  with  laryngeal  and  facial  movements, 
laughing  and  crying. 

MUSCLES    OF    THE    PERINEUM. 

The  muscles  of  the  perineum  are  situated  in  the  outlet  of  the  pelvis,  and 
consist  of  two* groups,  one  of  which  belongs  especially  to  the  organs  of 
generation  and  urethra,  the  other  to  the  termination  of  the  alimentary  canal. 
To  these  may  be  added  the  only  pair  of  muscles  which  is  proper  to  the 
pelvis,  the  coccygeus.  The  muscles  of  the  perineal  region  in  the  male, 
are  the 

Accelerator  urinse,  Sphincter  ani, 

Erector  penis,  Levator  ani, 

Compressor  urethra,  Coccygeus. 
Transversus  perinei, 

Dissection. — To  dissect  the  perineum,  the  subject  should  be  fixed  in 
the  position  for  lithotomy,  that  is,  the  hands  should  be  bound  to  the  soles 
of  the  feet,  and  the  knees  kept  apart.  An  easier  plan  is  the  drawing  of 
the  feet  upwards  by  means  of  a  cord  passed  through  a  hook  in  the  ceiling. 
Both  of  these  plans  of  preparation  have  for  their  object  the  full  exposure 
of  the  perineum.  And  as  this  is  a  dissection  which  demands  some  degjee 
of  delicacy  and  nice  manipulation,  a  strong  light  should  be  thrown  upou 
the  part.  Having  fixed  the  subject,  and  drawn  the  scrotum  upwards  by 
means  of  a  string  or  hook,  carry  an  incision  from  the  base  of  the  scrotum 
along  the  ramus  of  the  pubes  arid  ischium  and  tuberosity  of  the  ischium, 
to  a  point  parallel  with  the  apex  of  the  coccyx ;  then  describe  a  curve 
over  the  coccyx  to  the  same  point  on  the  opposite  side,  and  continue  the 
incision  onwards  along  the  opposite  tuberosity,  and  along  the  ramus  of  the 
ischium  and  of  the  pubes,  to  the  opposite  side  of  the  scrotum,  where  the 
two  extremities  maybe  connected  by  a  transverse  incision.  This  incision 
will  completely  surround  the  perineum,  following  very  nearly  the  outline 
of  its  boundaries.  Now  let  the  student  dissect  off  the  integument  care- 
fully from  the  whole  of  the  included  space,  and  he  will  expose  the  fatty 
cellular  structure  of  the  common  superficial  fascia,  which  exactly  resembles 
the  superficial  fascia  in  every  other  situation.  The  common  superficial 


220  MUSCLES  OF  THE  PERINEUM. 

fascia  is  then  to  be  removed  to  the  same  extent,  exposing  the  superficial 
perineal  fascia.  This  layer  is  also  to  be  turned  aside,  when  the  muscles 
of  the  genital  region  of  the  perineum  will  be  brought  into  view. 

The  ACCELERATORES  UfiiN^  (bulbo-cavernosus)  arise  from  a  tendinous 
point  in  the  centre  of  the  perineum  and  from  the  fibrous  raphe  of  the  two 
muscles.^    From  these  origins  the  fibres  diverge,  like  the  plumes  of  a  pen 
the  posterior  fibres  to  be  inserted  into  the  ramus  of  the  pubes  and  ischium 
the  middle  to  encircle  the  corpus  spongiosum,  and  meet  upon  its  upper 
side ;  and  the  anterior  to  spread  out  upon  the  corpus  cavernosum  on.  each 
side,  and  be  inserted,  partly  into  its  fibrous  structure,  and  partly  into  the 
fascia  of  the  penis.     The  posterior  and  middle  insertions  of  these  muscles 
are  best  seen,  by  carefully  raising  one  muscle  from  the  corpus  spongiosum 
and  tracing  its  fibres. 

Relations. — By  their  superficial  surface  with  the  superficial  perinea] 
fascia,  the  dartos,  the  superficial  vessels  and  nerves  of  the  perineum,  and 
on  each  side  with  the  erector  penis.  By  their  deep  surface  writh  the  corpus 
spongiosum  and  bulb  of  the  urethra. 

The  ERECTOR  PENIS  (ischio-cavernosus)  arises  from  the  ramus  and  tu- 
berosity  of  the  ischium,  and  curves  around  the  root  of  the  penis,  to  be  in- 
serted into  the  upper  surface  of  the  corpus  cavernosum,  where  it  is  con- 
tinuous with  a  strong  fascia  which  covers  the  dorsum  of  the  organ,  the 
fascia  penis. 

Relations. — By  its  superficial  surface  with  the  superficial  perineal  fascia, 
the  dartos,  and  the  superficial  perineal  vessels  and  nerve.  By  its  deep 
surface  with  the  corpus  cavernosum  penis. 

The  COMPRESSOR  URETH^E  (Wilson's  and  Guthrie's  muscles),  consists 
of  two  portions ;  one  of  which  is  transverse  in  its  direction,  and  passes  in- 
wards, to  embrace  the  membranous  urethra ;  the  other  is  perpendicular, 
and  descends  from  the  pubes.  The  transverse  portion,  particularly  de- 
scribed by  Mr.  Guthrie,  arises  by  a  narrow  tendinous  point,  from  the  upper 
part  of  the  ramus  of  the  ischium,  on  each  side,  and  divides  into  two  fasci- 
culi, which  pass  inwards  and  slightly  upwards,  and  embrace  the  membra- 
nous portion  of  the  urethra  and  Cowper's  glands.  As  they  pass  towards 
the  urethra,  they  spread  out  and  become  fan-shaped,  and  are  inserted  into 
a  tendinous  raphe  upon  the  upper  and  lower  surfaces  of  the  urethra,  ex  • 
tending  from  the  apex  of  the  prostate  gland,  to  which  they  are  attached 
posteriorly,  to  the  bulbous  portion  of  the  urethra,  with  which  they  are  con- 
nected in  front.  When  seen  from  above,  these  portions  resemble  two  fans, 
connected  by  their  expanded  border  along  the  middle  line  of  the  mem- 
branous urethra,  from  the  prostate  to  the  bulbous  portion  of  the  urethra. 
The  same  appearance  is  obtained  by  viewing  them  from  below. 

The  perpendicular  portion*  described  by  Mr.  Wilson,  arises  by  two  ten- 
dinous points  from  the  inner  surface  of  the  arch  of  the  pubes,  on  each  side 
of,  and  close  to,  the  symphysis.  The  tendinous  origins  soon  become 
muscular,  and  descend  perpendicularly,  to  be  inserted  into  the  upper  fas- 
ciculus of  the  transverse  portion  of  the  muscle  ;  so  that  it  is  not  a  distinct 
muscle  surrounding  the  membranous  portion  of  the  urethra,  and  support- 

•  Mr.  Tyrrell,  who  made  many  careful  dissections  of  the  muscles  of  the  perineum, 
did  not  observe  this  portion  of  the  muscle ;  he  considers  Wilson's  muscle  (with  some 
other  anatomists)  to  be  the  anterior  fibres  of  the  levator  ani,  not  uniting  beneath  the 
urethra,  as  described  by  Mr.  Wilson;  but  inserted  into  a  portion  of  the  pelvic  fascia 
timnted  be'ween  the  prostate  gland  and  rectum,  the  recto-vesical  fascia. 


TRANSVERSUS    PERINEI.  221 

ing  it  as  in  a  sling,  as  described  by  Mr.  Wilson,  but  merely  an  upper 
origin  of  the  transverse  muscle. 

Fig.  119.* 


The  compressor  urethras  may  be  considered  either  as  two  symmetrical 
muscles  meeting  at  the  raphe,  or  as  a  single  muscle :  I  have  adopted  the 
latter  course  in  the  above  description,  as  appearing  to  me  the  more  con- 
sistent with  the  general  connexions  of  the  muscle,  and  with  its  actions. 

The  TRANSVERSUS  PERINEI  arises  from  the  tuberosity  of  the  ischium 
on  each  side,  and  is  inserted  into  the  central  tendinous  point  of  the 
perineum,  f 

Relations. — By  its  superficial  surface  with  the  superficial  perineal  fascia, 
and  superficial  perineal  artery.  By  its  deep  surface  with  the  deep  perineal 
fascia,  and  internal  pudic  artery  and  veins.  By  its  posterior  border  it  is 
in  relation  with  that  portion  of  the  superficial  perineal  fascia  which  passes 
back  to  become  continuous  with  the  deep  fascia. 

To  dissect  the  compressor  urethra,  the  whole  of  the  preceding  muscles 
should  be  removed,  so  as  to  render  the  glistening  surface  of  the  deep  peri- 
neal fascia  quite  apparent.  The  anterior  layer  of  the  fascia  should  then 
be  carefully  dissected  away,  and  the  corpus  spongiosum  penis  divided 
through  its  middle,  separated  from  the  corpus  cavernosum,  and  drawn 
forwards,  to  put  the  membranous  portion  of  the  urethra,  upon  which  the 
muscle  is  spread  out,  on  the  stretch.  The  muscle  is,  however,  better 
seen  in  a  dissection  made  from  within  the  pelvis,  after  having  turned 

*  The  muscles  of  the  perineum.  1.  The  accelerators  urime  muscles;  the  figure  rests 
upon  the  corpus  spongiosum  penis.  2.  The  corpus  cavernosum  of  one  side.  3.  Tho 
erector  penis  of  one  side.  4.  The  transversus  perinei  of  one  side.  5.  The  triangular 
space  through  which  the  deep  perineal  fascia  is  seen.  6.  The  sphincter  ani ;  its  ante- 
rior extremity  is  cut  off.  7.  The  levator  ani  of  the  left  side  ;  the  deep  space  between 
the  tuberosity  of  the  ischium  (8)  and  the  anus,  is  the  ischio-rectal  fossa;  the  same  fossa 
is  seen  upon  the  opposite  side.  9.  The  spine  of  the  ischium.  10.  The  left  coccygeus 
muscle.  The  boundaries  of  the  perineum  are  well  seen  in  this  engraving.' 

f  I  have  twice  dissected  a  perineum  in  which  the  transversus  perinei  was  of  large 
size,  and  spread  out  as  it  approached  the  middle  line,  so  as  to  become  fan-shaped.  Thrt 
posterior  fibres  were  continuous  with  those  of  the  muscle  of  the  opposite  side ;  but  tho 
anterior  were  prolonged  forwards  upon  the  bulb  and  corpus  spongiosum  of  the  urethra, 
as  far  as  the  middle  of  the  penis,  forming  a  broad  layer  which  usurped  the  place  ar.i? 
office  of  the  accelerator  urinae. 

19* 


222  MUSCLES   OF  THE   PERINEUM. 

down  the  bladder  from  its  attachment  to  the  os  pubis,  and  removed  a 
plexus  of  veins  and  the  posterior  layer  of  the  deep  perineal  fascia. 

The  SPHINCTER  ANI  is  a  thin  and  elliptical  plane  of  muscle  closely  ad- 
herent to  the  integument,  and  surrounding  the  opening  of  the  anus.  It 
arises  posteriorly  in  the  superficial  fascia  around  the  coccyx,  and  by  a 
fibrous  raphe  from  the  apex  of  that  bone  ;  and  is  inserted  anteriorly  into 
the  tendinous  centre  of  the  perineum,  and  into  the  raphe  of  the  integument, 
nearly  as  far  forwards  as  the  commencement  of  the  scrotum. 

Relations. — By  its  superficial  surface  with  the  integument.  By  its  deep 
surface  with  the  internal  sphincter,  the  levator  ani,  the  cellular  tissue  and 
fat  in  the  ischio-rectal  fossa,  and  in  front  with  the  superficial  perineal 
fascia. 

The  SPHINCTER  ANI  INTERNUS  is  a  muscular  ring  embracing  the  ex- 
tremity of  the  intestine,  and  formed  by  an  aggregation  of  the  circular 
fibres  of  the  rectum. 

Part  of  the  levator  ani  may  be  seen  during  the  dissection  of  the  anal 
portion  of  the  perineum,  by  removing  the  fat  which  surrounds  the  termi- 
nation of  the  rectum  in  the  ischio-rectal  fossa.  But  to  study  the  entire 
muscle,  a  lateral  section  of  the  pelvis  must  be  made  by  sawing  through 
the  pubes  a  little  to  one  side  of  the  symphysis,  separating  the  bones 
behind  at  the  sacro-iliac  symphysis,  and  turning  down  the  bladder  and 
rectum.  The  pelvic  fascia  is  then  to  be  carefully  raised,  beginning  at  the 
base  of  the  bladder  and  proceeding  upwards,  until  the  whole  extent  of 
the  muscle  is  exposed. 

The  LEVATOR  ANI  is  a  thin  plane  of  muscular  fibres,  situated  on  each 
side  of  the  pelvis.  The  muscle  arises  from  the  inner  surface  of  the  os 
pubis,  from  the  spine  of  the  ischium,  and  between  those  points  from  the 
angle  of  division  between  the  obturator  and  the  pelvic  fascia.  Its  fibres 
descend,  to  be  inserted,  into  the  extremity  of  the  coccyx,  into  a  fibrous 
raphe  in  front  of  that  bone,  into  the  lower  part  of  the  rectum,  base  of  the 
bladder,  and  prostate  gland. 

In  the  female,  this  muscle  is  inserted  into  the  coccyx  and  fibrous  raphe, 
lower  part  of  the  rectum  and  vagina. 

Relations. — By  its  external  or  perineal  surface,  with  a  thin  layer  of 
fascia,  by  which,  and  by  the  obturator  fascia,  it  is  separated  from  the  ob- 
turator internus  muscle ;  with  the  fat  in  the  ischio-rectal  fossa,  the  deep 
perineal  fascia,  the  levator  ani,  and  posteriorly  with  the  gluteus  maximus. 
By  its  internal  or  pelvic  surface,  with  the  pelvic  fascia,  which  separates  it 
from  the  viscera  of  the  pelvis  and  peritoneum. 

The  COCCYGEUS  MUSCLE  is  a  tendino-muscular  layer  of  triangular  form. 
It  arises  from  the  spine  of  the  ischium,  and  is  inserted  into  the  side  of  the 
coccyx  and  lower  part  of  the  sacrum. 

Relations. — By  its  internal  or  pelvic  surface,  with  the  rectum ;  by  its 
external  surface,  with  the  lesser  and  greater  sacro-ischiatic  ligaments. 

The  muscles  of  the  perineum  in  the  female  are  the  same  as  in  the  male, 
and  have  received  analogous  names.  They  are  smaller  in  size,  and  are 
modified  to  suit  the  different  form  of  the  organs ;  they  are — 

Constricto-  vagina?,  Sphincter  ani, 

Erector  clitoridis,  Levator  ani, 

Transversus  perinei,  Coccygeus. 
Compressor  urethra, 


MUSCLES  OF  THE  UPPER  EXTREMITY.          223 

The  Constrictor  vagina  is  analogous  to  the  acceleratores  urinae ;  it  is 
continuous,  posteriorly,  with  the  sphincter  ani,  interlacing  with  its  fibres, 
and  is  inserted,  anteriorly,  into  the  sides  of  the  corpora  cavernosa,  and 
fascia  of  the  clitoris. 

The  Transversus  perinei  is  inserted  into  the  side  of  the  constrictor  vagi- 
nae, and  the  levator  ani  into  the  side  of  the  vagina. 

The  other  muscles  are  precisely  similar  in  their  attachments  to  those  in 
fhe  male. 

Actions. — The  acceleratores  urina3  being  continuous  at  the  middle  line, 
and  attached  on  each  side  to  the  bone,  by  means  of  their  posterior  fibres, 
will  support  the  bulbous  portion  of  the  urethra,  and  acting  suddenly,  will 
propel  the  semen,  or  the  last  drops  of  urine,  from  the  canal.  The  poste- 
rior and  middle  fibres,  according  to  Krause,*  contribute  towards  the  erec- 
tion of  the  corpus  spongiosum,  by  producing  compression  upon  the  venous 
structure  of  the  bulb  ;  and  the  anterior  fibres,  according  to  Tyrrell, f  assist 
in  the. erection  of  the  entire  organ  by  compressing  the  vena  dorsalis,  by 
means  of  their  insertion  into  the  fascia  penis.  The  erector  penis  becomes 
entitled  to  its  name  from  spreading  out  upon  the  dorsum  of  the  organ, 
into  a  membranous  expansion,  (fascia  penis,)  which,  according  to  Krause, 
compresses  the  dorsal  vein  during  the  action  of  the  muscle,  and  especially 
after  the  erection  of  the  organ  has  commenced.  The  transverse  muscles 
serve  to  steady  the  tendinous  centre,  that  the  muscles  attached  to  it  may 
obtain  a  firm  point  of  support.  According  to  Cruveilhier,  they  draw  the 
anus  backwards  during  the  expulsion  of  the  faeces,  and  antagonize  the 
levatores  ani,  which  carry  the  anus  forwards.  The  compressor  urethra?, 
taking  its  fixed  point  from  the  ramus  of  the  ischium  at  each  side,  can, 
says  Mr.  Guthrie,  "  compress  the  urethra  so  as  to  close  it ;  I  conceive 
completely,  after  the  manner  of  a  sphincter."  The  transverse  portion  will 
also  have  a  tendency  to  draw  the  urethra  downwards,  whilst  the  perpen- 
dicular portion  will  draw  it  upwards  towards  the  os  pubis.  The  inferior 
fasciculus  of  the  transverse  muscle,  enclosing  Cowper's  glands,  will  assist 
those  bodies  in  evacuating  their  secretion.  The  external  sphincter,  being 
a  cutaneous  muscle,  contracts  the  integument  around  the  anus,  and  by  its 
attachment  to  the  tendinous  centre,  and  to  the  point  of  the  coccyx,  assists 
Ihe  levator  ani  in  giving  support  to  the  opening  during  expulsive  efforts. 
The  internal  sphincter  contracts  the  extremity  of  the  cylinder  of  the  intes- 
tine. The  use  of  the  levator  ani  is  expressed  in  its  name.  It  is  the  an- 
tagonist of  the  diaphragm  and  the  rest  of  the  expulsory  muscles,  and 
series  to  support  the  rectum  and  vagina  during  their  expulsive  efforts. 
The  levator  ani  acts  in  unison  with  the  diaphragm,  and  rises  and  falls  like 
that  muscle  in  forcible  respiration.  Yielding  to  the  propulsive  action  of 
the  abdominal  muscles,  it  enables  the  outlet  of  the  pelvis  to  bear  a  greatei 
force  than  a  resisting  structure,  and  on  the  remission  of  such  action  it  re- 
stores the  perineum  to  its  original  form.  The  coccygei  muscles  restore 
the  coccyx  to  its  natural  position,  after  it  has  been  pressed  backwards 
during  defalcation  or  during  parturition. 

MUSCLES    OF    THE    UPPER    EXTREMITY. 

The  muscles  of  the  upper  extremity  may  be  arranged  into  groups  cor 
responding  with  the  different  regions  of  the  limb,  thus  : 

*  Miiller,  Archiv.  fur  Anatomic,  Physiologic,  &c.     1837 
•J"  Lectures  in  the  College  of  Surgeons.     1839. 


224 


MUSCLES  OF  THE  UPPER  EXTREMITY. 


Lateral  Thoracic  Region, 
Serratus  magnus. 


Anterior  Thoracic  Region. 
Pectoralis  major, 
Pectoralis  minor, 
Subclavius. 

Posterior  Scapular  Region. 
Supra-spinatus, 
Infra-spinatus, 
Teres  minor, 
Teres  major. 

Acromial  Region. 
Deltoid. 


Ulterior  Scapular  Region. 
Subscapularis. 


interior  Humeral  Region. 

Coraco-brachialis, 
Biceps, 
Brachialis  anticus. 

interior  Brachial  Region. 
Superficial  Layer. 

Pronator  radii  teres, 
Flexor  carpi  radialis, 
Palmaris  longus, 
Flexor  sublimis  digitorum, 
Flexor  carpi  ulnaris. 


Deep  Layer. 

Flexor  profundus  digitorum, 
Flexor  longus  pollicis, 
Pronator  quadratus. 


Posterior  Humeral  Region. 
Triceps. 


Posterior  Brachial  Region. 
Superficial  Layer. 

Supinator  longus, 
Extensor  carpi  radialis  longior, 
Extensor  carpi  radialis  brevior, 
Extensor  communis  digitorum, 
Extensor  minimi  digiti, 
Extensor  carpi  ulnaris, 
Anconeus. 

Deep  Layer. 

Supinator  brevis, 
Extensor  ossis  metacarpi  pollicis, 
Extensor  primi  internodii  pollicis, 
Extensor  secundi  internodii  pollicis 
Extensor  indicis. 


Radial  Region  (Thenar). 

Abductor  pollicis, 
Flexor  ossis  metacarpi 

(opponens), 
Flexor  brevis  pollicis, 
Adductor  pollicis. 

Palmar  Region. 
Lumbricales, 
Interossei  palmares, 
Interossei  dorsales. 


HAND. 

Ulnar  Region  (Hypothenar). 

Palmaris  brevis, 
Abductor  minimi  digiti, 
Flexor  brevis  minimi  digiti, 
Adductor  minimi  digiti. 


interior  Thoracic  Region. 

Pectoralis  major, 
Pectoralis  minor, 
Subclavius. 


PECTORALIS    MAJOR    AND    MINOR.  225 

THssection.  —  Make  an  incision  along  the  line  of  the  clavicle,  from  the 
•jppei  part  of  the  sternum  to  the  acromion  process ;  a  second  alono-  the 
lower  border  of  the  great  pectoral  muscle,  from  the  lower  end  of  the  ster- 
num to  the  insertion  of  its  tendon  into  the  humerus,  and  connect  the  two 
by  a  third,  carried  longitudinally  along  the  middle  of  the  sternum.  The 
integument  and  superficial  fascia  are  to  be  dissected  together  from  off  the 
fibres  of  the  muscle,  and  always  in  the  direction  of  their  course.  For  this 
purpose  the  dissector,  if  he  have  the  right  arm,  will  commence  with  the 
lower  angle  of  the  flap  ;  if  the  left,  with  the  upper  angle.  He  wrill  thus 
^xpose  the  pectoralis  major  muscle  in  its  whole  extent. 

The  PECTORALIS  MAJOR  muscle  arises  from  the  sternal  two-thirds  of 
the  clavicle,  from  one  half  the  breadth  of  the  sternum  its  whole  length, 
from  the  cartilages  of  all  the  true  ribs,  excepting  the  first  and  last,  and 
from  the  aponeurosis  of  the  external  oblique  muscle  of  the  abdomen.  It 
is  inserted  by  a  broad  tendon  into  the  anterior  bicipital  ridge  of  the  hu- 
merus. 

That  portion  of  the  muscle  which  arises  from  the  clavicle  is  separated 
from  that  connected  with  the  sternum  by  a  distinct  cellular  interspace ; 
hence  we  speak  of  the  clavicular  portion  and  sternal  portion  of  the  pecto- 
ralis major.  The  fibres  from  this  very  extensive  origin  converge  towards 
a  narrow  insertion,  giving  the  muscle  a  radiated  appearance.  But  there 
is  a  peculiarity  about  the  formation  of  its  tendon  which  must  be  carefully 
noted.  The  whole  of  the  lower  border  is  folded  inwards  upon  the  upper 
portion,  so  that  the  tendon  is  doubled  upon  itself.  Another  peculiarity 
results  from  this  arrangement:  the  fibres  of  the  upper  portion  of  the  muscle 
are  inserted  into  the  lower  part  of  the  bicipital  ridge ;  and  those  of  the 
lower  portion,  into  the  upper  part. 

Relations.  —  By  its  external  surface  with  the  fibres  of  origin  of  the 
platysma  myoides,  the  mammary  gland,  the  superficial  fascia  and  inte- 
gument. By  its  internal  surface,  on  the  thorax,  with  the  clavicle,  the 
sternum,  the  costal  cartilages,  intercostal  muscles,  subclavius,  pectoralis 
minor,  and  serratus  magnus ;  in  the  axilla,  with  the  axillary  vessels  and 
glands.  By  its  external  border  with  the  deltoid,  from  which  it  is  separated 
above  by  a  cellular  interspace  lodging  the  cephalic  vein  and  the  descend- 
ing branch  of  the  thoracico-acromialis  artery.  Its  lower  border  forms  the 
anterior  boundary  of  the  axillary  space. 

The  pectoralis  major  is  now  to  be  removed  by  dividing  its  fibres  along 
the  lower  border  of  the  clavicle,  and  then  carrying  the  incision  perpendi- 
cularly downwards,  parallel  to  the  sternum,  and  at  about  three  inches 
from  its  border.  Divide  some  loose  cellular  tissue,  and  several  small 
branches  of  the  thoracic  arteries,  and  reflect  the  muscle  outwards.  We 
thus  bring  into  view  a  region  of  considerable  interest,  in  the  middle  of 
which  is  situated  the  pectoralis  minor. 

The  PECTORALIS  MINOR  arises  by  three  digitations  from  the  third,  fourth, 
and  fifth  ribs,  and  is  inserted  into  the  anterior  border  of  the  coracoid  pro- 
cess of  the  scapula  by  a  broad  tendon. 

Relations.  —  By  its  anterior  surface  with  the  pectoralis  major  and  supe- 
rior thoracic  vessels  and  nerves.  By  its  posterior  surface  with  the  ribs, 
the  intercostal  muscles,  serratus  magnus,  axillary  space,  and  axillary 
vessels  and  nerves.  Its  upper  border  forms  the  lowrer  boundary  of  a  trian- 
gular space  bounded  above  by  the  costo-coracoid  membrane,  and  mter- 

p 


226  ANTERIOR   SCAPULAR   REGION. 

nally  by  the  ribs.  In  this  space  are  found  the  axillary  vessels  and  nerves., 
and  in  it  the  subclavian  artery  may  be  tied  below  the  clavicle. 

The  SUBCLAVIUS  muscle  arises  by  a  round  tendon  from  the  cartilage 
of  the  first  rib,  and  is  inserted  into  the  under  surface  of  the  clavicle.  This 
muscle  is  concealed  by  the  costo-coracoid  membrane,  an  extension  of  the 
deep  cervical  fascia,  by  which  it  is  invested. 

Relations. — By  its  upper  surface  with  the  clavicle.  By  the  lower  with 
the  subclavian  artery  and  vein  and  brachial  plexus,  which  separate  it  from 
the  first  rib.  In  front  with  the  pectoralis  major,  the  costo-coracoid  mem- 
brane being  interposed. 

Actions. — The  pectoralis  major  draws  the  arm  against  the  thorax,  while 
its  upper  fibres  assist  the  upper  part  of  the  trapezius  in  raising  the  shoulder 
as  in  supporting  weights.  The  lower  fibres  depress  the  shoulder  with  the 
aid  of  the  latissimus  dorsi.  Taking  its  fixed  point  from  the  shoulder, 
the  pectoralis  major  assists  the  pectoralis  minor,  subclavius,  and  serratus 
magnus,  in  drawing  up  and  expanding  the  chest.  The  pectoralis  minor, 
in  addition  to  this  action,  draws  upon  the  coracoid  process,  and  assists  in 
rotating  the  scapula  upon  the  chest.  The  subclavius  draws  the  clavicle 
downwards  and  forwards,  and  thereby  assists  in  steadying  the  shoulder. 
All  the  muscles  of  this  group  are  agents  in  forced  respiration,  but  are  in- 
capable of  acting  until  the  shoulders  are  fixed. 

Lateral  Thoracic  Region. 
Serratus  magnus. 

The  SERRATUS  MAGNUS  (serratus,  indented  like  the  edge  of  a  saw), 
arises  by  fleshy  serrations  from  the  nine  upper  ribs  excepting  the  first,  and 
extends  backwards  upon  the  side  of  the  chest,  to  be  inserted  into  the  whole 
length  of  the  base  of  the  scapula  upon  its  anterior  aspect.  In  structure 
the  muscle  is  composed  of  three  portions,  a  superior  portion  formed  by 
two  serrations  attached  to  the  second  rib,  and  inserted  into  the  inner  sur- 
face of  the  superior  angle  of  the  scapula,  a  middle  portion  composed  of 
the  serrations  connected  with  the  third  and  fourth  ribs,  and  inserted  into 
the  greater  part  of  the  posterior  border,  and  an  inferior  portion  consisting 
of  the  last  five  serrations  which  indigitate  with  the  obliquus  externus  and 
form  a  thick  muscular  fasciculus  which  is  inserted  into  the  scapula  near  its 
inferior  angle. 

Relations. — By  its  superficial  surface  with  the  pectoralis  major  and  mi- 
nor, the  subscapularis,  and  the  axillary  vessels  and  nerves.  By  its  deep 
surface  with  the  ribs  and  intercostal  muscles,  to  which  it  is  connected  by 
an  extremely  loose  cellular  tissue. 

Jlctions. — The  serratus  magnus  is  the  great  external  inspiratory  muscle, 
raising  the  ribs  when  the  shoulders  are  fixed,  and  thereby  increasing  the 
ravity  of  the  chest.  Acting  upon  the  scapula,  it  draws  the  shoulder  for- 
ward's, as  we  see  to  be  the  case  in  diseased  lungs,  where  the  chest  has 
become  almost  fixed  from  apprehension  of  the  expanding  action  of  the 
respiratory  muscles. 

Anterior  Scapular  Region. 
Subscapularis. 

The  SUBSCAPULARIS  muscle  arises  from  the  wrhole  of  the  under  surface 
of  the  scapula  excepting  the  superior  and  inferior  angle,  and  terminates  by 


POSTERIOR  SCAPULAR  REGION.  227 

a  broad  and  thick  tendon,  which  is  inserted  into  the  lesser  tuberosity  of  the 
humerus.  The  substance  of  the  muscle  is  traversed  by  several  intersecting 
membranous  layers  from  which  muscular  fibres  arise,  the  intersections 
being  attached  to  the  ridges  on  the  surface  of  the  scapula.  Its  tendon 
forms  part  of  the  capsule  of  the  joint,  glides  over  a  large  bursa  which 
separates  it  from  the  base  of  the  coracoid  process,  and  is  lined  by  a  pro- 
longation of  the  synovial  membrane  of  the  articulation. 

Relations. — By  its  anterior  surface  with  the  serratus  magnus,  coraco- 
brachialis,  and  axillary  vessels  and  nerves.  By  its  posterior  surface  with 
the  scapula,  the  subscapular  vessels  and  nerves,  and  the  shoulder  joint. 

Action. — It  rotates  the  head  of  the  humerus  inwards,  and  is  a  powerful 
defence  to  the  join.1.  When  the  arm  is  raised,  it  cLraws  the  humerus 
downwards. 

Posterior  Scapular  Region. 

Supra-spinatus,  Teres  minor, 

Infra-spinatus,  Teres  major. 

The  SUPRA-SPINATUS  muscle  (supra,  above ;  spina,  the  spine)  arises 
from  the  whole  of  the  supra-spinous  fossa,  and  is  inserted  into  the  upper- 
most depression  on  the  great  tuberosity  of  the  humerus.  The  tendon  of 
this  muscle  cannot  be  well  seen  until  the  acromion  process  is  removed. 

Relations. — By  its  upper  surface,  with  the  trapezius,  the  clavicle,  acro- 
mion, and  coraco-acromion  ligament.  From  the  trapezius  it  is  separated 
by  a  strong  fascia.  By  its  lower  surface,  with  the  supra-spinous  fossa,  the 
supi  a-scapular  vessels  and  nerve,  and  the  upper  part  of  the  shoulder  joint, 
forming  part  of  the  capsular  ligament. 

The  INFRA-SPINATUS  (infra,  beneath  ;  spina,  the  spine)  is  covered  in  by 
a  layer  of  tendinous  fascia,  which  must  be  removed  before  the  fibres  of  the 
muscle  can  be  seen,  the  deltoid  muscle  having  been  previously  turned 
down  from  its  scapular  origin.  It  arises  from  the  whole  of  the  infra-spinous 
fossa,  and  from  the  fascia  above-mentioned,  and  is  inserted  into  the  middle 
depression  upon  the  greater  tuberosity  of  the  humerus. 

Relations. — By  its  posterior  surface,  with  the  deltoid,  latissimus  dorsi 
and  integument.  By  its  anterior  surface,  with  the  infra-spinous  fossa,  su- 
perior and  dorsal  scapular  vessels,  and  shoulder  joint ;  its  tendon  being 
lined  by  a  prolongation  from  the  synovial  membrane.  By  its  upper  border, 
it  is  in  relation  with  the  spine  of  the  scapula,  and  by  the  lower,  with  the 
teres  minor,  with  which  it  is  closely  united. 

The  TERES  MINOR  muscle  (teres,  round)  arises  from  the  middle  third 
of  the  inferior  border  of  the  scapula,  and  is  inserted  into  the  lower  depres- 
sion on  the  great  tuberosity  of  the  humerus.  The  tendons  of  these  three 
muscles,  with  that  of  the  subscapularis,  are  in  immediate  contact  with  the 
shoulder  joint,  and  form  part  of  its  ligamentous  capsule,  thereby  preserving 
the  solidity  of  the  articulation.  They  are  therefore  the  structures  most 
frequently  ruptured  in  dislocation  of  the  head  of  the  humerus. 

Relations.  —  By  its  posterior  surface,  with  the  deltoid,  latissimus  dorsi 
and  integument.  By  its  anterior  surface,  with  the-  inferior  border,  and 
part  of  the  dorsum  of  the  scapula,  the  dorsalis  scapulae  vessels,  scapular 
head  of  the  triceps,  and  shoulder  joint.  By  its  upper  border,  with  the 
infra-spinatus ;  and  by  the  lower,  with  the  latissimus  dorsi,  teres  major, 
and  long  head  of  the  triceps. 


228  ACROMIAL    REGION. 

The  TEBJES  MAJOR  muscle  arises  from  the  lower  thira  of  the  inferior 
border  of  the  scapula,  encroaching  a  little  upon  its  dorsal  aspect,  and  is 
inserted  into  the  posterior  bicipital  ridge.  Its  tendon  lies  immediately 
behind  that  of  the  latissimus  dorsi,  from  which  it  is  separated  by  a  syno- 
vial  membrane. 

Relations. — By  its  posterior  surface,  with  the  latissimus  dorsi,  scapula 
head  of  the  triceps  and  integument.     By  its  anterior  surface,  with  th 
subscapularis,  latissimus  dorsi,  coraco-brachialis,  short  head  of  the  biceps 
axillary  vessels,  and  branches  of  the  brachial  plexus.    By  its  upper  border, 
it  is  in  relation  with  the  teres  minor,  from  which  it  is  separated  by  the 
scapular  head  of  the  triceps ;  and  by  the  lower,  it  forms  with  the  latissimus 
dorsi,  the  lower  and  posterior  border  of  the  axilla. 

A  large  triangular  space  exists  between  the  two  teres  muscles,  which  is 
divided  into  two  minor  spaces  by  the  long  head  of  the  triceps. 

Actions.  —  The  supra-spinatus  raises  the  arm  from  the  side  ;  but  only 
feebly,  from  the  disadvantageous  direction  of  the  force.  The  infra-spinatus 
and  teres  minor  are  rotators  of  the  head  of  the  humerus  outwards.  The 
most  important  use  of  these  three  muscles  is  the  protection  of  the  joint, 
and  defence  against  displacement  of  the  head  of  the  humerus,  in  which 
action  they  co-operate  with  the  subscapularis.  The  teres  major  combines, 
with  the  latissimus  dorsi,  in  rotating  the  arm  inwards,  and  at  the  same 
time  carrying  it  towards  the  side,  and  somewhat  backwards. 

Acromial  Region. 
Deltoid. 

The  convexity  of  the  shoulder  is  formed  by  a  large  triangular  muscle, 
the  deltoid  (A,  delta ;  sT5os,  resemblance),  which  arises  from  the  outer  third 
of  the  clavicle,  from  the  acromion  process,  and  from  the  whole  length  of 
the  spine  of  the  scapula.  The  fibres  from  this  broad  origin  converge  to 
the  middle  of  the  outer  side  of  the  humerus,  where  they  are  inserted  into 
a  rough  triangular  elevation.  This  muscle  is  remarkable  for  its  coarse 
texture,  and  for  its  numerous  tendinous  intersections,  from  which  mus- 
cular fibres  arise.  The  deltoid  muscle  may  now  be  cut  awray  from  its 
origin,  and  turned  down,  for  the  purpose  of  bringing  into  view  the 
muscles  and  tendons  placed  immediately  around  the  shoulder  joint.  In 
so  doing,  a  large  bursa  will  be  seen  between  the  under  surface  of  the 
muscle  and  the  head  of  the  humerus. 

Relations.  —  By  its  superficial  surface,  with  a  thin  aponeurotic  fascia,  a 
few  fibres  of  the  platysma  myoides,  the  superficial  fascia  and  integument. 
By  its  deep  surface,  with  the  shoulder  joint,  from  which  it  is  separated  by 
a  thin  tendinous  fascia,  and  by  a  synovial  bursa ;  with  the  coraco-acromial 
ligament,  coracoid  process,  pectoralis  minor,  coraco-brachialis,  both  heads 
of  the  biceps,  tendon  of  the  pectoralis  major,  tendon  of  the  supra-spinatus, 
infra-spinatus,  teres  minor,  teres  major,  scapular  and  external  head  of  the 
triceps,  the  circumflex  vessels  anterior  and  posterior,  and  humerus.  By 
its  anterior  border,  with  the  external  border  of  the  pectoralis  major,  from 
which  it  is  separated  by  a  cellular  interspace,  lodging  the  cephalic  vein 
and  descending  branch  of  the  thoracico-acromialis  artery.  Its  posterior 
border  is  thin  and  tendinous  above,  where  it  is  connected  with  the  apo- 
neurotic covering  of  the  infra-spinatus  muscle,  and  thick  below. 

•fictions.  —  The  deltoid  is  the  elevator  muscle  of  the  arm  in  a  direct 


ANTERIOR    HUMERAL    REGION. 


229 


120  * 


tine,  and  by  means  of  its  extensive  origin  can  carry  the  arm  forwards  or 
backwards,  so  as  to  range  with  the  hand  a  considerable  segment  of  a  large 
I'ircle.  The  arm,  raised  by  the  deltoid,  is  a  good 
illustration  of  a  lever  of  the  third  power,  so  common 
m  the  animal  machine,  by  which  velocity  is  gained 
?t  the  expense  of  power.  In  this  lever,  the  weight 
^hand)  is  at  one  extremity,  the  fulcrum  (the  glenoid 
cavity)  at  the  opposite  end,  and  the  power  (the  in- 
sertion of  the  muscle)  between  the  two,  but  nearer 
to  the  fulcrum  than  to  the  weight. 

Anterior  Humeral  Region. 

Coraco-brachialis, 
Biceps, 
Brachialis  anticus. 

Dissection.  —  These  muscles  are  exposed,  on  the 
removal  of  the  integument  and  fascia  from  the  ante- 
rior half  of  the  upper  arm,  and  the  clearing  away  of 
the  cellular  tissue. 

The  CORACO-BRACHIALIS,  a  name  composed  of  its 
points  of  origin  and  insertion,  arises  from  the  cora- 
coid  process  in  common  with  the  short  head  of  the 
biceps ;  and  is  inserted  into  a  rough  line  on  the 
inner  side  of  the  middle  of  the  humerus. 

Relations.  —  By  its  anterior  surface  with  the  deltoid,  and  pectoralis 
major.  By  its  posterior  surface,  with  the  shoulder  joint,  the  humerus, 
subscapularis,  teres  major,  latissimus  dorsi,  short  head  of  the  triceps,  and 
anterior  circumflex  vessels.  By  its  internal  border  with  the  axillary  and 
brachial  vessels  and  nerves,  particularly  with  the  median  and  external 
cutaneous  nerve,  by  the  latter  of  which  it  is  pierced.  By  the  external 
border  with  the  short  head  of  the  biceps  and  brachialis  anticus. 

The  BICEPS  (bis — xsipaXai,  two  heads)  arises  by  two  tendons,  one  the 
short  head,  from  the  coracoid  process  in  common  with  the  coraco-brachi- 
alis ;  the  other  the  long  head,  from  the  upper  part  of  the  glenoid  cavity. 
The  muscle  is  inserted  by  a  rounded  tendon,  into  the  tubercle  of  the  ra- 
dius. The  long  head,  a  long  slender  tendon,  passes  through  the  capsular 
ligament  of  the  shoulder  joint  enclosed  in  a  sheath  of  the  synovial  mem- 
brane ;  after  leaving  the  cavity  of  the  joint,  it  is  lodged  in  the  deep  groove 
that  separates  the  two  tuberosities  of  the  humerus,  the  bicipital  groove. 
A  small  synovial  bursa  is  interposed  between  the  tendon  of  insertion,  and 
the  tubercle  of  the  radius.  Jit  the,  bend  of  the  elbow,  the  tendon  of  the 
biceps  gives  off  from  its  inner  side  a  broad  tendinous  band,  which  protects 
the  brachial  artery,  and  is  continuous  with  the  fascia  of  the  fore-arm. 

Relations. — By  its  anterior  surface  with  the  deltoid,  pectoralis  major, 
superficial  and  deep  fascia  and  integument.  By  its  posterior  surface  the 

*  The  muscles  of  the  anterior  aspect  of  the  upper  arm.  1.  The  coracoid  process  oe 
the  scapula.  2.  The  coraco-clavioular  ligament  (trapezoicl),  passing  upwards  to  the 
scapular  end  of  the  clavicle.  3.  The  coraco-acromial  ligament,  passing  outwards  to  the 
acromion.  4.  The  subscapularis  muscle.  5.  The  teres  major;  the  triangular  space 
above  this  muscle  is  that  through  which  the  dorsalis  scapulae  vessels  pass.  6.  The 
coraco-brachialis.  7.  The  biceps.  8.  The  upper  end  of  the  radius.  9.  The  brachialis 
anticus ;  a  portion  of  the  muscle  is  seen  on  the  outer  side  of  the  tendon  of  the  biceps 
10.  The  internal  head  of  the  triceps. 

20 


230 


POSTERIOR    HUMERAL    REGION. 


short  head  rests  upon  the  subscapularis,  from  which  it  is  separated  by  a 
bursa.  In  the  rest  of  its  extent  the  muscle  is  in  relation  with  the  humerus, 
the  teres  major,  latissimus  dorsi,  and  brachialis  anticus ;  from  the  latter  it 
is  separated  ^>y  the  external  cutaneous  nerve.  By  its  inner  border  with 
the  coraco-brachialis,  brachial  artery  arid  veins,  and  median  nerve ;  the 
brachial  vessels  crossing  its  tendon  at  the  bend  of  the  elbow.  By  its 
outer  border  with  the  deltoid  and  supinator  longus. 

The  BRACHIALIS  ANTICUS  is  a  broad  muscle  covering  the  whole  of  the 
anterior  surface  of  the  lower  part  of  the  humerus ;  it  arises  by  two  fleshy 
serrations  from  the  depressions  on  either  side  of  the  insertion  of  the  del- 
toid, from  the  anterior  surface  of  the  humerus,  and  from  the  interrauscular 
septa  attached  to  the  condyloid  ridges.  Its  fibres  converge  to  be  inserted 
into  the  coronoid  process  of  the  ulna. 

Relations. — By  its  anterior  surface  with  the  biceps,  external  cutaneous 
nerve,  brachial  artery  and  veins,  and  median  nerve.  By  its  posterior  sur- 
face with  the  humerus,  anterior  ligament  of  the  elbow  joint,  and  inter- 
muscular  aponeurosis.  The  latter  separates  it  from  the  triceps.  By  its 
external  border  with  the  supinator  longus,  extensor  carpi  radialis  longior, 
musculo-spiral  nerve,  and  recurrent  radial  artery.  By  its  internal  border 
with  the  intermuscular  aponeurosis,  which  separates  it  from  the  triceps 
and  ulnar  nerve,  and  with  the  pronator  radii  teres. 

Actions. — The  coraco-brachialis  draws  the  humerus  inwards,  and  assists 
in  flexing  it  upon  the  scapula.  The  biceps  and  brachialis  anticus  are 
flexors  of  the  fore-arm,  and  the  former  a  supinator.  The  brachialis  anticus 
is  a  powerful  protection  to  the  elbow  joint. 

Fig.  121*  Posterior  Humeral  Region. 

Triceps  extensor  cubiti. 

Dissection. — Remove  the  integument  and  fascia 
from  the  posterior  aspect  of  the  upper  arm. 

The  TRICEPS  (rpfig  xsgiaXwi,  three  heads)  arises 
by  three  heads.  Considered  in  relation  to  their 
length,  these  heads  have  been  named  long,  short, 
and  middle;  and  in  reference  to  their  position, 
internal,  external,  and  middle ;  the  term  middle, 
in  the  former  case,  referring  to  the  external  head, 
and  in  the  latter  case  to  the  long  head.  This  has 
given  rise  to  much  confusion  and  misunderstand- 
ing. I  shall,  therefore,  confine  myself  to  the  de- 
signations derived  from  their  relations.  The  ex- 
ternal head  arises  from  the  humerus,  commencing 
immediately  below  the  insertion  of  the  teres  minor, 
and  from  the  intermuscular  septum  attached  to  the 
external  condyloid  ridge.  The  internal  head 
(short)  arises  from  the  humerus,  commencing  im- 
mediately below  the  insertion  of  the  teres  major, 
and  from  the  intermuscular  septum  attached  to 
the  internal  condyloid  ridge.  The  scapular  head 
(long)  lies  between  the  two  others,  and  arises 
from  the  upper  third  of  the  inferior  border  of  the 

*  A  posterior  view  of  the  upper  arm,  showing  the  triceps  muscle.  1.  Its  external 
rfvvl.  2.  Its  long,  or  scapular  head.  3.  Its  internal,  or  short  head.  4.  The  olecranou 
ptoi-uss  of  the  ulna.  5.  Th«  rad'"j  6  The  capsular  ligament  of  the  shoulder  join:. 


ANTERIOR    BRACIIIAL    REGION. 


231 


scapula.  The  three  heads  unite  to  form  a  broad  muscle,  which  is  inserted 
by  an  aponeurotic  tendon  into  the  olecranon  process  of  the  ulna ;  a  small 
bursa  is  situated  between  its  tendon  and  the  upper  part  of  the  olecranon. 

The  scapular  head  of  the  triceps  passes  between  the  teres  minor  and 
major,  and  divides  the  triangular  space  between  those  two  muscles  into 
two  smaller  spaces,  one  of  which  is  triangular,  the  other  quadrangular. 
The  triangular  space  is  bounded  by  the  teres  minor,  teres  major,  and 
scapular  head  of  the  triceps ;  it  gives  passage  to  the  dorsalis  scapulae  ar- 
tery and  veins.  The  quadrangular  space  is  bounded  on  three  sides  by 
the  three  preceding  muscles,  and  on  the  fourth  by  the  humerus.  Through 
this  space  pass  the  posterior  circumflex  artery  and  veins,  and  circumflex 
nerve. 

A  few  of  the  deep  fibres  of  the  triceps,  attached  above  to  the  humerus 
and  below  to  the  capsule  of  the  elbow  joint,  have  been  named  sub-anco- 
neus ;  they  are  analogous  to  the  sub-crureus. 

Relations. — By  its  posterior  surface  with  the  deep  and  superficial  fascia 
and  integument.  By  its  anterior  surface  with  the  superior  profunda  artery, 
musculo-spiral  nerve,  humerus,  intermuscular  aponeuroses  which  separate 
it  from  the  brachialis  anticus,  and  with  the  elbow  joint.  The  scapular 
head  is  in  relation  posteriorly  with  the  deltoid  and  teres  minor ;  anteriorly 
with  the  subscapularis,  teres  major,  and  latissimus  dorsi;  and  externally 
with  the  posterior  circumflex  vessels  and  nerve. 

Actions.  —  The  triceps  is  an  extensor  of  the  fore-  Fis- 122-* 

arm. 

interior  Brachial  Region. 

Superficial  Layer. 
Pronator  radii  teres, 
Flexor  carpi  radialis, 
Palmaris  longus, 
Flexor  sublimis  digitorum, 
Flexor  carpi  ulnaris. 

Dissection.  —  These  muscles  are  brought  into  view 
by  making  an  incision  through  the  integument  along 
the  middle  line  of  the  fore-arm,  crossing  each  extre- 
mity by  a  transverse  incision,  and  turning  aside  the 
flaps.  The  superficial  and  deep  fascia  are  then  to  be 
removed. 

The  PRONATOR  RADII  TERES  arises  by  two  heads ; 
one  from  the  inner  condyle  of  the  humerus,  fascia  of 
the  fore-arm,  and  intermuscular  aponeurosis ;  the 
other  from  the  coronoid  process  of  the  ulna ;  the  me- 
dian nerve  passing  between  them.  Its  tendon  is  flat 
and  inserted  into  the  middle  third  of  the  oblique  ridge 
of  the  radius.  The  two  heads  of  this  muscle  are  best 
examined  by  cutting  through  that  which  arises  from 
the  inner  condyle,  and  turning  it  aside.  The  second 
head  will  then  be  seen  with  the  median  nerve  lying 
across  it. 

*  Superficial  layer  of  the  muscles  of  the  fore-arm.  1.  The  lower  part  of  the  bicepa, 
with  its  tendon.  2.  A  part  of  the  brachialis  anticus,  seen  beneath  the  biceps.  3.  A  pan 
of  the  triceps  4.  The  tronator  radii  teres.  5.  The  flexor  carpi  radiaiis.  6  The  pai 


0,32  FLEXOR    CARPI    RADIAL1S 

Relations.  —  By  its  anterior  surface  with  the  fascia  of  the  fore-arm,  the 
supinator  longus,  extensor  carpi  radialis  longior  and  breyior,  radial  artery 
and  veins,  and  radial  nerve.  By  its  posterior  surface  with  the  brachialis 
anticus,  flexor  sublimis  digitorum,  the  ulnar  artery  and  veins,  and  the  me- 
dian nerve  after  it  has  passed  between  the  two  heads  of  the  muscle.  By 
its  upper  border  it  forms  the  inner  boundary  of  the  triangular  space,  in 
which  the  termination  of  the  brachial  artery  is  situated.  By  its  lower 
border  it  is  in  relation  with  the  flexor  carpi  radialis. 

The  FLEXOR  CARPI  RADIALIS  arises  from  the  inner  condyle  and  from 
the  intermuscular  fascia.  Its  tendon  passes  through  a  groove  formed  by 
the  scaphoid  bone  and  trapezium,  to  be  inserted  into  the  base  of  the  meta- 
carpal  bone  of  the  index  finger. 

Relations. — By  its  anterior  surface  with  the  fascia  of  the  fore-arm,  and 
at  the  wrist  with  the  tendinous  canal  through  which  its  tendon  passes. 
By  its  posterior  surface  with  the  flexor  sublimis  digitorum,  flexor  longus 
pollicis,  wrist-joint,  and  groove  in  the  scaphoid  and  trapezium  bones.  By 
its  outer  border  with  the  pronator  radii  teres,  and  radial  artery  and  veins. 
By  its  inner  border  with  the  palmaris  longus.  The  tendon  is  surrounded 
by  a  synovial  membrane  where  it  plays  through  the  tendinous  canal  of  the 
•wrist. 

The  PALMARIS  LONGUS  is  a  small  muscle  which  arises  from  the  inner 
condyle,  and  from  the  intermuscular  fascia.  It  is  inserted  into  the  annular 
ligament  and  palmar  fascia.  Occasionally  this  muscle  is  wanting. 

Relations. — By  its  anterior  surface  with  the  fascia  of  the  fore-arm.  By 
the  posterior  surface  with  the  flexor  sublimis  digitorum :  to  the  external 
side  by  the  flexor  carpi  radialis ;  and  to  the  internal  side  by  the  flexor  carpi 
ulnaris. 

Cut  the  flexor  carpi  radialis  and  palmaris  longus  from  their  origins,  in 
order  to  obtain  a  good  view  of  the  whole  extent  of  origin  of  the  flexor 
sublimis  digitorum. 

The  FLEXOR  SUBLIMIS  DIGITORUM  (perforatus)  arises  from  the  inner 
condyle,  internal  lateral  ligament,  coronoid  process  of  the  ulna,  and  ob- 
lique line  of  the  radius.  The  median  nerve  and  ulnar  artery  pass  between 
its  origins.  It  divides  into  four  tendons,  which  pass  beneath  the  annular 
ligament  into  the  palm  of  the  hand,  and  are  inserted  into  the  base  of  the 
second  phalanges  of  the  fingers,  splitting  at  their  terminations  to  give 
passage  to  the  tendons  of  the  deep  flexors ;  thence  its  designation,  per- 
forates. In  the  theca3  of  the  fingers  several  small  tendinous  fasciculi  are 
generally  found,  which  pass  between  the  phalanges  and  the  edges  of  the 
tendons ;  these  have  been  termed  the  vincula  accessoria. 

Relations. — In  the  fore-arm.  By  its  anterior  surface  with  the  pronator 
radii  teres,  flexor  carpi  radialis,  palmaris  longus,  flexor  carpi  ulnaris,  and' 
the  deep  fascia.  By  its  posterior  surface  with  the  flexor  profundus  digi- 
torum, flexor  longus  pollicis,  ulnar  artery,  veins  and  nerve,  and  median 
nerve.  This  muscle  frequently  sends  a  fasciculus  to  the  flexor  longus 
pollicis  or  flexor  profundus.  In  the  hand :  its  tendons,  after  passing  be- 

maris  longus.     7    One  of  the  fasciculi  of  the  flexor  sublimis  digitorum ;  the  rest  of  the 

muscle  is  seen  beneath  the  tendons  of  the  palmaris  longus  and  flexor  carpi  radialis.     8. 

lexor  carpi  ulnaris.     9.  The  palmar  fascia.     10.  The  palmaris  brevis  muscle.     11. 

The  abductor  pollicis  muscle.     ]2.  One  portion  of  the  flexor  brevis  pollicis ;  the  leading 

crosses  a  part  of  the  adductor  pollicis.     13.  The  supinator  longus  muscle.     14.  The 

extensor  nssis  metacarpi,  and  extensor  primi  internodii  pollicis.  curving  around  the   ovver 

border  of  the  fore-arm. 


FLEXOR    LONGUS    POLLICIS.  233 

neath  the  annular  ligament,  are  in  relation  superficially  with  the  superficial 
palmar  arch,  and  palmar  fascia ;  and  deeply  with  the  tendons  of  the  deep 
flexor  and  lumbricales. 

The  FLEXOR  CARPI  ULNARIS  arises  by  two  heads,  one  from  the  inner 
condyle,  the  other  from  the  olecranon  and  upper  two-thirds  of  the  inner 
border  of  the  ulna.  Its  tendon  is  inserted  into  the  pisiform  bone,  and  base 
of  the  metacarpal  bone  of  the  little  finger. 

Relations. — By  its  anterior  surface  with  the  fascia  of  the  fore-arm,  with 
which  it  is  closely  united  superiorly.  By  its  posterior  surface  with  the 
flexor  sublimis  digitorum,  flexor  profundus,  pronator  quadratus,  and  ulnar 
artery,  veins,  and  nerve.  By  its  radial  border  with  the  palmaris  longus, 
and  in  the  lower  third  of  the  fore-arm  with  the  ulnar  vessels  and  nerve. 
The  ulnar  nerve,  and  the  posterior  ulnar  recurrent  artery,  pass  between 
its  two  heads  of  origin. 

Deep  layer. 

Flexor  profundus  digitorum, 
Flexor  longus  pollicis, 
Pronator  quadratus. 

Dissection. — This  group  is  brought  into  view  by  removing  the  flexoi 
sublimis,  and  drawing  aside  the  pronator  radii  teres. 

The  FLEXOR  PROFUNDUS  DIGITORUM  (perforans)  arises  from  the  upper 
two-thirds  of  the  ulna  and  part  of  the  interosseous  membrane,  and  termi- 
nates in  four  tendons,  which  pass  beneath  the  annular  ligament,  and  be- 
tween the  two  slips  of  the  tendons  of  the  flexor  sublimis  (hence  its  desig- 
nation, perforans),  to  be  inserted  into  the  base  of  the  last  phalanges.  The 
tendon  of  the  index  finger  is  always  distinct  from  the  rest,  the  other  three 
tendons  being  more  or  less  intimately  connected  by  the  cellular  tissue  and 
tendinous  slips. 

Four  little  muscular  fasciculi,  called  lumbricales,  are  connected  with 
the  tendons  of  this  muscle  in  the  palm.  They  will  be  described  with  the 
muscles  of  the  hand. 

Relations. — In  the  fore-arm.  By  its  anterior  surface  with  the  flexor 
sublimis  digitorum,  flexor  carpi  ulnaris,  median  nerve,  and  ulnar  artery, 
veins,  and  nerve.  By  its  posterior  surface  with  the  ulna,  the  interosseous 
membrane,  the  pronator  quadratus,  and  the  wrist  joint.  By  its  radial 
border  with  the  flexor  longus  pollicis,  the  anterior  interosseous  artery  and 
nerve  being  interposed.  By  its  ulnar  border  with  the  flexor  carpi  ulnaris. 
In  the  hand :  its  tendons  are  in  relation  superficially  with  the  tendons  of 
the  superficial  flexor ;  and  deeply  with  the  interossei  muscles,  adductor 
pollicis,  and  deep  palmar  arch.  In  the  fingers :  the  tendons  of  the  deep 
flexor  are  interposed  between  the  tendons  of  the  superficial  flexor  and  the 
phalanges,  and  give  attachment  to  vincula  accessoria. 

The  FLEXOR  LONGUS  POLLICIS  arises  from  the  upper  two-thirds  of  the 
radius,  and  part  of  the  interosseous  membrane.  Its  tendon  passes  beneath 
the  annular  ligament,  to  be  inserted  into  the  base  of  the  last  phalanx  of 
the  thumb. 

Relations. — By  its  anterior  surface  with  the  flexor  sublimis  digitorum, 
flexor  carpi  radialis,  supinator  longus,  and  radial  artery  and  veins.  By 
its  posterior  surface  with  the  radius,  interosseous  membrane,  pronator 
quadratus,  and  wrist  joint.  By  its  ulnar  border  it  is  separated  from  the 
flexor  profundus  digitorum  by  the  anterior  interosseous  artery  and  nerve 
20* 


234 


POSTERIOR    BRACHIAL    REGION. 


Fig.  123.* 


In  the  hand :  after  passing  beneath  the  annular  ligament,  it  is  lodged  in 
the  interspace  between  the  two  portions  of  the  flexor  brevis  pollicis,  and 
afterwards  in  the  tendinous  theca  of  the  phalanges. 

If  the  tendons  of  the  last  two  muscles  be  drawn  aside  or  divided,  the 
third  muscle  of  this  group  will  be  brought  into  view,  lying  across  the 
lower  part  of  the  two  bones. 

The  PRONATOR  QUADRATUS  arises  from  the  ulna,  and  is  inserted  into  the 
lower  fourth  of  the  oblique  line,  on  the  outer  side  of  the  radius.  This 
muscle  occupies  about  the  lower  fourth  of  the  two  bones,  is  broad  at  its 
origin,  and  narrower  at  its  insertion. 

Relations. — By  its  anterior  surface  with  the  ten- 
dons of  the  supinator  longus,  flexor  carpi  radialis, 
flexor  longus  pollicis,  flexor  profundus  digitorum, 
and  flexor  carpi  ulnaris,  radial  artery  and  veins,  and 
ulnar  artery,  veins,  and  nerve.  By  its  posterior  sur- 
face with  the  radius,  ulna,  and  interosseous  mem- 
brane. 

Actions. — The  pronator  radii  teres  and  pronator 
quadratus  muscles  rotate  the  radius  upon  the  ulna, 
and  render  the  hand  prone.  The  remaining  muscles 
are  flexors :  two  flexors  of  the  wrist,  flexor  carpi  ra- 
dialis and  ulnaris ;  two  of  the  fingers,  flexor  sublimis 
and  profundus,  the  former  flexing  the  second  pha- 
langes, the  latter  the  last ;  one  flexor  of  the  last  pha- 
lanx of  the  thumb,  flexor  longus  pollicis.  The 
palmaris  longus  is  primarily  a  tensor  of  the  palmar 
fascia,  and  secondarily  a  flexor  of  the  wrist  and  fore- 
arm. 

Posterior  Brachial  Region. 

Superficial  layer. 
Supinator  longus, 
Extensor  carpi  radialis  longior, 
Extensor  carpi  radialis  brevior, 
Extensor  communis  digitorum, 
Extensor  minimi  digiti, 
Extensor  carpi  ulnaris, 
Anconeus. 

Dissection. — The  integument  is  to  be  divided  and 
turned  aside,  and  the  fasciae  removed  in  the  same 
manner  as  for  the  anterior  brachial  region. 

The  SUPINATOR  LONGUS  muscle  is  placed  along  the  radial  border  of  the 
fore-arm.  It  arises  from  the  external  condyloid  ridge  of  the  humerus, 
nearly  as  high  as  the  insertion  of  the  deltoid,  and  is  inserted  into  the  base 
of  the  styloid  process  of  the  radius. 

Relations. — By  its  superficial  surface  with  the  extensor  ossis  metacarpi 
pollicis,  extensor  primi  internodii  pollicis,  and  fascia  of  the  fore-arm.  By 

*The  deep  layer  of  muscles  of  the  fore-arm.  1.  The  internal  lateral  ligament  of  the 
elbow  joint.  2.  The  anterior  ligament.  3.  The  orbicular  ligament  of  the  head  of  the 
radius.  4.  The  flexor  profundus  digitorum  muscle.  5.  The  flexor  longus  pollicis.  6. 
The  pronator  quadratus.  7.  The  adductor  pollicis  muscle.  8.  The  dorsal  interosseous 
muscle  of  the  middle  finger,  and  palmar  interosseous  of  the  ring  finger.  9.  The  dorsal 
Miterosser.us  muscle  of  the  ring  finger,  and  palmar  interosseous  of  the  little  finger. 


EXTENSOR    COMMUNIS    DIGITORUM. 


235 


Fig.  124 .« 


its  deep  surface  with  the  brachialis  anticus,  extensor  carpi  radialis  longior, 
tendon  of  the  biceps,  supinator  brevis,  pronator  radii  teres,  flexor  carpi 
radialis,  flexor  subHmis  digitorum,  flexor  longus  pollicis,  pronator  quad- 
ratus,  radius,  musculo-spiral  nerve,  radial  and  posterior  interosseous  nerve, 
and  radial  artery  and  veins. 

This  muscle  must  be  divided  through  the  middle,  and  the  two  ends 
turned  to  either  side  to  expose  the  next  muscle. 

The  EXTENSOR  CARPI  RADIALIS  LONGIOR  arises 
from  the  external  condyloid  ridge  below  the  pre- 
ceding, and  from  the  intermuscular  fascia.  Its  ten- 
don passes  through,  a  groove  in  the  radius,  imme- 
diately behind  the  styloid  process,  to  be  inserted 
into  the  base  of  the  metacarpal  bone  of  the  index 
finger. 

Relations. — By  its  superficial  surface,  with  the 
supinator  longus,  extensor  ossis  metacarpi  pollicis, 
extensor  primi  internodii  pollicis,  extensor  secundi 
internodii  pollicisj  radial  nerve,  fascia  of  the  fore- 
arm, and  posterior  annular  ligament.  By  its  deep 
surface,  with  the  brachialis  anticus,  extensor  carpi 
radialis  brevior,  radius  and  wrist  joint. 

The  EXTENSOR  CARPI  RADIALIS  BREVIOR  is  seen 
by  drawing  aside  the  former  muscle.  It  arises  from 
the  external  condyle  of  the  humerus  and  intermus- 
cular fascia,  and  is  inserted  into  the  base  of  the  me- 
tacarpal bone  of  the  middle  finger.  Its  tendon  is 
lodged  in  the  same  groove,  on  the  radius,  with  the 
extensor  carpi  radialis  longior. 

Relations.  —  By  its  superficial  surface,  with  the 
extensor  carpi  radialis  longior,  extensor  ossis  meta- 
carpi pollicis,  extensor  primi  internodii  pollicis,  ex- 
tensor secundi  internodii  pollicis,  fascia  of  the  fore- 
arm, and  posterior  annular  ligament.  By  its  deep 
surface,  with  the  supinator  brevis,  tendon  of  the 
pronator  radii  teres,  radius  and  wrist  joint.  By  its 
ulnar  border,  with  the  extensor  communis  digitorum. 

The  EXTENSOR  COMMUNIS  DIGITORUM  arises  from  the  external  condyle, 
and  intermuscular  fascia;  and  divides  into  four  tendons,  which  are  inserted 
into  the  second  and  third  phalanges  of  the  fingers.  At  the  metacarpo- 
phalangeal  articulation,  each  tendon  becomes  narrow  and  thick,  and  sends 
a  thin  fasciculus  upon  each  side  of  the  joint.  It  then  spreads  out,  and 
receiving  the  tendon  of  the  lumbricalis,  and  some  tendinous  fasciculi  from 

*  The  superficial  layer  of  muscles  of  the  posterior  aspect  of  the  fore-arm.  1.  The 
lower  part  of  the  biceps.  2.  Part  of  the  brachialis  anticus.  3.  The  lower  part  of  the 
triceps,  inserted  into  the  olecranon.  4.  The  supinator  longus.  5.  The  extensor  carpi 
radialis  longior.  6.  The  extensor  carpi  radialis  brevior.  7.  The  tendons  of  insertion 
of  the?e  two  muscles.  8.  The  extensor  communis  digitorum.  9.  The  extensor  minimi 
digiti.  10.  The  extensor  carpi  ulnaris.  11.  The  anconeus.  12.  Part  of  the  flexor  carpi 
ulnaris.  13.  The  extensor  ossis  metacarpi  and  extensor  primi  internodii  muscle,  lying 
together.  14.  The  extensor  secundi  internodii ;  its  tendon  is  seen  crossing  the  two  ten- 
dons of  the  extensor  carpi  radialis  longior  and  brevior.  15.  The  posterior  annular  liga- 
ment. The  tendons  of  the  common  extensor  are  seen  upon  the  back  of  the  hand,  and 
their  mode  of  distributior.  OD  the  dorsum  of  the  fingers. 


236  ANCONEUS. 

the  interossei,  forms  a  broad  aponeurosis,  which  covers  the  whole  of  the 
posterior  aspect  of  the  finger.  At  the  first  phalangeal  joint,  the  aponeu- 
osis  divides  into  three  slips.  The  middle  slip  is  inserted  into  the  base 
.)f  the  second  phalanx,  and  the  two  lateral  portions  are  continued  onwards 
on  each  side  of  the  joint,  to  be  inserted  into  the  last.  Little  oblique  ten- 
dinous slips  connect  the  tendons  of  the  middle,  ring,  and  little  finger,  as 
they  cross  the  back  of  the  hand. 

Relations.  —  By  its  superficial  surface,  with  the  fascia  of  the  fore-arm 
and  back  of  the  hand,  and  with  the  posterior  annular  ligament.  By  its 
deep  surface,  with  the  supinator  brevis,  extensor  ossis  metacarpi  pollicis, 
extensor  primi  internodii,  extensor  secundi  internodii,  extensor  indicis, 
posterior  interosseous  artery  and  nerve,  wrist  joint,  metacarpal  bones  and 
interossei  muscles,  and  phalanges.  By  its  radial  border,  with  the  extensor 
carpi  radialis  longior  and  brevior.  By  the  ulnar  border,  with  the  extensor 
minimi  digiti,  and  extensor  carpi  ulnaris. 

The  EXTENSOR  MINIMI  DIGITI  (auricularis)  is  an  offset  from  the  extensor 
communis,  with  which  it  is  connected  by  means  of  a  tendinous  slip. 
Passing  down  to  the  inferior  extremity  of  the  ulna,  it  traverses  a  distinct 
fibrous  sheath,  and  at  the  metacarpo-phalangeal  articulation  unites  with 
the  tendon  derived  from  the  common  extensor.  The  common  tendon 
then  spreads  out  into  a  broad  expansion,  which  divides  into  three  slips, 
to  be  inserted,  as  in  the  other  fingers,  into  the  last  two  phalanges.  It  is 
to  this  muscle  that  the  little  finger  owes  its  power  of  separate  extension ; 
and  from  being  called  into  action  when  the  point  of  the  finger  is  intro- 
duced into  the  meatus  of  the  ear,  for  the  purpose  of  removing  unpleasant 
sensations  or  producing  titillation,  the  muscle  \vas  called  by  the  old 
writers  "auricularis." 

The  EXTENSOR  CARPI  ULNARIS  arises  from  the  external  condyle  and 
from  the  upper  two-thirds  of  the  border  of  the  ulna.  Its  tendon  passes 
through  the  posterior  groove,  in  the  lower  extremity  of  the  ulna,  to  be 
inserted  into  the  base  of  the  metacarpal  bone  of  the  little  finger. 

Relations.  —  By  its  superficial  surface,  with  the  fascia  of  the  fore- arm, 
and  posterior  annular  ligament.  By  its  deep  surface,  with  the  supinator 
brevis,  extensor  ossis  metacarpi  pollicis,  extensor  secundi  internodii,  ex- 
tensor indicis,  ulna,  and  wrist  joint.  By  its  radial  border,  it  is  in  relation 
with  the  extensor  communis  digitorum,  and  extensor  minimi  digiti :  and 
by  the  ulnar  border,  with  the  anconeus. 

The  ANCONEUS  is  a  small  triangular  muscle,  having  the  appearance  of 
being  a  continuation  of  the  triceps ;  it  arises  from  the  outer  condyle,  and 
is  inserted  into  the  olecranon  and  triangular  surface  on  the  upper  extremity 
of  the  ulna. 

Relations. — By  its  superficial  surface  with  a  strong  tendinous  aponeu- 
rosis derived  from  the  triceps.  By  its  deep  surface  with  the  elbow  joint, 
orbicular  ligament,  and  slightly  with  the  supinator  brevis. 

Deep  Layer. 

Supinator  brevis, 
Extensor  ossis  metacarpi  pollicis, 
Extensor  primi  internodii  pollicis, 
Extensor  secundi  internodii  pollicis, 
Extensor  indicis. 


EXTENSOR    PRIMI    1NTERXODII    POLLICIS. 


237 


Fig  125.» 


Dissection. — The  muscles  of  the  superficial  layer 
should  be  removed  in  order  to  bring  the  deep  group 
completely  into  view. 

The  SUPINATOR  BREVIS  cannot  be  seih  in  its  en- 
tire extent  until  the  radial  extensors  of  the  carpus 
are  divided  from  their  origin.  It  arises  from  the 
external  condyle,  from  the  external  lateral  and  or- 
bicular ligament,  and  from  the  ulna,  and  winds 
around  the  upper  part  of  the  radius,  to  be  inserted 
into  the  upper  third  of  its  oblique  line.  The  pos- 
terior interosseous  artery  and  nerve  are  seen  perfo- 
rating the  lower  border  of  this  muscle. 

Relations. — By  its  superficial  surface  with  the 
pronator  radii  teres,  supinator  longus,  extensor 
carpi  radialis  longior  and  brevior,  extensor  corn- 
munis  digitorum,  extensor  carpi  ulnaris,  anconeus, 
the  radial  artery  and  veins,  the  musculo-spiral 
nerve,  radial  and  posterior  interosseous  nerve. 
By  its  deep  surface  with  the  elbow-joint  and  its 
ligaments,  the  interosseous  membrane,  and  the 
radius. 

The  EXTENSOR  Ossis  METACARPI  POLLICIS  is 
placed  immediately  below  the  supinator  brevis. 
It  arises  from  the  ulna,  interosseous  membrane,  and 
radius,  and  is  inserted,  as  its  name  implies,  into  the 
base  of  the  metacarpal  bone  of  the  thumb.  Its 
tendon  passes  through  the  groove  immediately  in 
front  of  the  styloid  process  of  the  radius. 

Relations. — By  its  superficial  surface  with  the  extensor  carpi  ulnaris, 
extensor  minimi  digiti,  extensor  comraunis  digitorurn,  fascia  of  the  fore- 
arm, and  annular  ligament.  By  its  deep  surface  with  the  ulna,  interosse- 
ous membrane,  radius,  tendons  of  the  extensor  carpi  radialis  longior  and 
brevior,  and  supinator  longus,  and  at  the  wrist  with  the  radial  artery. 
By  its  upper  border  with  the  edge  of  the  supinator  brevis.  By  its  lower 
border  with  the  extensor  secundi  and  primi  internodii.  The  muscle  is 
crossed  by  branches  of  the  posterior  interosseous  artery  and  nerve. 

The  EXTENSOR  PRIMI  INTERXODII  POLLICIS,  the  smallest  of  the  muscles 
in  this  layer,  arises  from  the  interosseous  membrane  and  ulna,  and  passes 
through  the  same  groove  with  the  extensor  ossis  metacarpi,  to  be  inserted 
into  the  base  of  the  first  phalanx  of  the  thumb. 

Relations. — The  same  as  those  of  the  preceding  muscle  with  the  excep- 
tion of  the  extensor  carpi  ulnaris.  The  muscle  accompanies  the  extensor 
ossis  metacarpi. 

The  EXTENSOR  SECUNDI  INTERNODII  POLLICIS  arises  from  the  ulna,  and 
interosseous  membrane.  Its  tendon  passes  through  a  distinct  canal  in  the 
annular  ligament,  and  is  inserted  into  the  base  of  the  last  phalanx  of  the 
thumb. 

*  The  deep  layer  of  muscles  on  the  posterior  aspect  of  the  fore-arm.  1.  The  lo\vei 
part  of  the  humerus.  2.  The  olecranon.  3.  The  ulna.  4.  The  anconeus  muscle.  5 
The  supinator  brevis  muscle.  6.  The  extensor  ossis  metacarpi  pollicis.  7.  The  exten 
sor  primi  internodii  pollicis.  8.  The  extensor  secundi  internodii  pollicis.  9.  The  ex 
tensor  indicis.  10.  The  first  dorsal  interosseous  muscle.  The  other  three  dorsal  inter 
ossei  are  seen  between  the  metacarpal  bones  of  their  respective  fingers. 


238  MUSCLES    OF    THE    HAND. 

Relations. — By  its  external  surface  with  the  same  relations  as  the  exten 
sor  ossis  metacarpi.  By  its  deep  surface  with  the  ulna,  inter.osseous  mem.' 
brane,  radius,  wrist  joint,  radial  artery,  and  metacarpal  bone  of  the  thumb 
The  muscle  is  placed  between  tHt  extensor  primi  interne dii  and  extensoi 
indicis. 

The  EXTENSOR  INDICIS  arises  from  the  ulna,  as  high  up  as  the  extensor 
ossis  metacarpi  pollicis,  and  from  the  interosseous  membrane.  Its  tendon 
passes  through  a  distinct  groove  in  the  radius,  and  is  inserted  into  the 
aponeurosis  formed  by  the  common  extensor  tendon  of  the  index  finger. 

Relations. — The  same  as  those  of  the  preceding  muscle,  with  the  ex- 
ception of  the  hand,  where  the  tendon  rests  upon  the  metacarpal  bone  of 
the  fore  finger  and  second  interosseous  muscle,  and  has  no  relation  with 
the  radial  artery. 

The  tendons  of  the  extensors,  as  of  the  flexor  muscles  of  the  fore- arm, 
are  provided  with  synovial  bursse  as  they  pass  beneath  the  annular  liga- 
ments :  those  of  the  back  of  the  wrist  have  distinct  sheaths,  formed  by  the 
posterior  annular  ligament. 

Actions. — The  anconeus  is  associated  in  its  action  with  the  triceps  ex- 
tensor cubiti :  it  assists  in  extending  the  fore-arm  upon  the  arm.  The 
supinator  longus  and  brevis  effect  the  supination  of  the  fore-arm,  and  an- 
tagonize the  two  pronators.  The  extensor  carpi  radialis  longior  and  bre- 
vior,  and  ulnaris,  extend  the  wrist  in  opposition  to  the  two  flexors  of  the 
carpus.  The  extensor  communis  digitorum  restores  the  fingers  to  the 
straight  position,  after  being  flexed  by  the  two  flexors,  sublimis  and  pro- 
fundus.  The  extensor  ossis  metacarpi,  primi  internodii,  and  secundi  in- 
ternodii  pollicis,  are  the  especial  extensors  of  the  thumb,  and  serve  to 
balance  the  actions  of  the  flexor  ossis  metacarpi,  flexor  brevis,  and  flexor 
longus  pollicis.  The  extensor  indicis  gives  the  character  of  extension  to 
the  index  finger,  and  is  hence  named  "  indicator,"  and  the  extensor 
minimi  digiti  supplies  that  finger  with  the  power  of  exercising  a  distinct 
extension. 

MUSCLES    OF    THE    HAND. 

Radial  or  Thenar  Region. 

Abductor  pollicis,  Flexor  brevis  pollicis, 

Flexor  ossis  metacarpi  (opponens),  Adductor  pollicis. 

Dissection. — The  hand  is  best  dissected  by  making  an  incision  along 
the  middle  of  the  palm,  from  the  wrist  to  the  base  of  the  fingers,  and 
crossing  it  at  each  extremity  by  a  transverse  incision,  then  turning  aside 
the  flaps  of  integument.  For  exposing  the  muscles  of  the  radial  region, 
the  removal  of  the  integument  and  fascia  on  the  radial  side  will  be  suffi- 
cient. 

The  ABDUCTOR  POLLICIS  is  a  small,  thin  muscle,  which  arises  from  the 
scaphoid  bone  and  annular  ligament.  It  is  inserted  into  the  base  of  the 
first  phalanx  of  the  thumb. 

Relations. — By  its  superficial  surface,  with  the  external  portion  of  the 
palmar  fascia.  By  its  deep  surface,  with  the  flexor  ossis  metacarpi.  On 
its  inner  side  it  is  separated  by  a  narrow  cellular  interspace  from  the  flexor 
brevis  pollicis. 

This  muscle  must  be  divided  from  its  origin  and  turned  upwards,  in 
order  to  see  the  next. 


MUSCLES    OF    THE    HAND. 


23S 


Fig.  126  * 


The  FLEXOR  Ossis  METACARPI  (oppo- 
nens  pollicis)  arises  from  the  trapezium 
and  annular  ligament,  and  is  inserted 
into  the  whajp  length  of  the  metacarpal 
bone. 

Relations. — By  its  superficial  surface, 
with  the  abductor  pollicis.  By  its  deep 
surface,  with  the  trapezio-metacarpal  ar- 
ticulation, and  with  the  metacarpal  bone. 
Internally,  with  the  flexor  brevis  pollicis. 

The  flexor  ossis  metacarpi  may  now 
be  divided  from  its  origin  and  turned 
aside,  in  order  to  show  the  next  muscle. 

The  FLEXOR  BREVIS  POLLICIS  consists 
of  two  portions,  between  which  lies  the 
tendon  of  the  flexor  longus  pollicis.  The 
external  portion  arises  from  the  trapezium 
and  annular  ligament ;  the  internal  por- 
tion, from  the  trapezoides  and  os  mag- 
num. They  are  both  inserted  into  the 
base  of  the  first  phalanx  of  the  thumb,  having  a  sesamoid  bone  in  each  of 
their  tendons,  to  protect  the  joint. 

Relations. — By  its  superficial  surface,  with  the  external  portion  of  the 
palmar  fascia.  By  its  deep  surface,  with  the  adductor  pollicis,  tendon  of 
the  flexor  carpi  radialis,  and  trapezio-metacarpal  articulation.  By  its  ex- 
ternal surface,  with  the  flexor  ossis  metacarpi  and  metacarpal  bone.  By 
its  inner  surface,  with  the  tendons  of  the  long  flexor  muscles  and  first 
lumbricalis. 

The  ADDUCTOR  POLLICIS  is  a  triangular  muscle ;  it  arises  from  the  whole 
length  of  the  metacarpal  bone  of  the  middle  finger ;  and  the  fibres  converge 
to  its  insertion  into  the  base  of  the  first  phalanx. 

Relations. — By  its  anterior  surface  with  the  flexor  brevis  pollicis,  ten- 
dons of  the  deep  flexor  of  the  fingers,  lumbricales,  and  deep  palmar  arch. 
By  its  posterior  surface  with  the  metacarpal  bones  of  the  index  and  middle 
fingers,  the  interossei  of  the  second  interosseous  space,  and  the  abductor 
indjcis.  Its  inferior  border  is  subcutaneous. 

Ulnar,  or  Hypothenar  Region. 
Palmaris  brevis,  • 
Abductor  minimi  digiti, 
Flexor  brevis  minimi  digiti, 
Flexor  ossis  metacarpi  (adductor). 

«  The  muscles  of  the  hand.  1.  The  annular  ligament.  2,  2.  The  origin  and  insertion 
of  the  abductor  pollicis  muscle;  the  middle  portion  has  been  removed.  3.  The  flexoi 
ossis  metacarpi,  or  opponens  pollicis.  4.  One  portion  of  the  flexor  brevis  pollicis.  5 
The  deep  portion  of  the  flexor  brevis  pollicis.  6.  The  adductor  pollicis.  7,  7.  The 
lumbricales  muscles,  arising  from  the  deep  flexor  tendons,  upon  which  the  numbers  are 
placed.  The  tendons  of  the  flexor  snblimis  have  been  removed  from  the  palm  of  trie 
hand.  8.  One  of  the  tendons  of  the  deep  flexor,  passing  between  the  two  terminal  slips 
of  the  tendon  of  the  flexor  sublimis,  to  reach  the  last  phalanx.  9.  The  tendon  of  the 
flexor  longus  pollicis,  passing  between  the  two  portions  of  the  flexor  brevis  to  the  last 
phalanx.  10.  The  abductor  minimi  digiti.  11.  The  flexor  brevis  minimi  digiti.  The 
edge  of  the  flexor  ossis  metacarpi,  or  adductor  minimi  digiti,  is  seen  projecting  beyond 
the  inner  border  of  the  flexor  brevis.  12.  The  prominence  of  the  pisiform  bone.  13 
The  first  dorsal  interosseous  muscle. 


240  MUSCLES    OF    THE    HAND. 

Dissection. — Turn  aside  the  ulnar  flap  of  integument  in  the  palm  of  the 
hand :  in  doing  this,  a  subcutaneous  muscle,  the  palmaris  brevis  will  be 
exposed.  After  examining  this  muscle  remove  it  with  the  deep  fascia,  in 
order  to  bring  into  view  the  muscles  of  the  little  finger.  ^ 

The  PALMARIS  BREVIS  is  a  thin  plane  of  muscular  fibres  which  arises 
from  the  annular  ligament  and  palmar  fascia,  and  passes  transversely  in- 
wards, to  be  inserted  into  the  integument  on  the  inner  border  of  the  hand. 

Relations. — By  its  superficial  surface  with  the  fat  and  integument  of  the 
ball  of  the  little  finger.  By  its  deep  surface  with  the  internal  portion  of  the 
palmar  fascia,  which  separates  it  from  the  ulnar  artery  veins,  and  nerve, 
and  from  the  muscles  of  the  inner  border  of  the  hand. 

The  ABDUCTOR  MINIMI  DIGITI  is  a  small  tapering  muscle  which  arises 
from  the  pisiform  bone,  and  is  inserted  into  the  base  of  the  first  phalanx  of 
the  little  finger. 

Relations. — By  its  superficial  surface  with  the  internal  portion  of  the 
deep  fascia  and  the  palmaris  brevis :  by  its  deep  surface  with  the  flexor 
ossis  metacarpi  and  metacarpal  bone.  By  its  inner  border  with  the  flexor 
brevis  minimi  digiti. 

The  FLEXOR  BREVIS  MINIMI  DIGITI  is  a  small  muscle  arising  from  the 
unciform  bone  and  annular  ligament,  and  inserted  into  the  base  of  the  first 
phalanx.  It  is  sometimes  wanting. 

Relations. — By  its  superficial  surface  with  the  internal  portion  of  the 
palmar  fascia,  and  the  palmaris  brevis.  By  its  deep  surface  with  the  flexor 
ossis  metacarpi,  and  metacarpal  bone.  Externally  with  the  abductor 
minimi  digiti,  from  which  it  is  separated  near  its  origin  by  the  deep  palmar 
branch  of  the  ulnar  nerve  and  communicating  artery.  Internally  with  the 
tendons  of  the  flexor  sublimis  and  profundus. 

The  FLEXOR  Ossis  METACARPI  (adductor,  opponens)  arises  from  the 
unciform  bone  and  annular  ligament,  and  is  inserted  into  the  whole  length 
of  the  metacarpal  bone  of  the  little  finger. 

Relations. — By  its  superficial  surface  with  the  flexor  brevis  and  abductor 
minimi  digiti.  By  its  deep  surface  with  the  interossei  muscles  of  the  last 
metacarpal  space,  the  metacarpal  bone,  and  the  flexor  tendons  of  the  little 
finger. 

Palmar  Region. 
Lumbricales, 
Interossei  palmares, 
Interosse.i  dorsales. 

The  LUMBRICALES,  four  in  number,  are  accessories  to  the  deep  flexor 
muscle.  They  arise  from  the  tendons  of  the  deep  flexor  ;  the  first  and 
second  from  the  palmar  side,  the  third  from  the  ulnar,  and  the  fourth  from 
the  radial  side ;  and  are  inserted  into  the  aponeurotic  expansion  of  the 
extensor  tendons  on  the  radial  side  of  the  fingers.  The  third,  or  that  of 
the  tendon  of  the  ring  finger,  sometimes  bifurcates,  otherwise  it  is  inserted 
wholly  into  the  extensor  tendon  of  the  middle  finger. 

Relations. — In  the  palm  of  the  hand  with  the  flexor  tendons  ;  at  their 
insertion,  with  the  tendons  of  the  interossei  and  the  metacarpo-phalangeal 
articulations. 

The  PALMAR  INTEROSSEI,  three  in  number,  are  placed  upon  the  meta- 
carpal bones,  rather  than  between  them.  They  arise  from  the  base  of  the 
metacarpal  bone  of  one  finger,  and  are  inserted  into  the  base  of  the  first 


MUSCLES    OF    THE    HAND. 


241 


Fig.  127  • 


phalanx  and  aponeurotic  expansion  of  tne  extensor  tendon  of  the  same 
finger.  The  first  belongs  to  the  index  finger;  the  second  to  the  .ring 
finger ;  and  the  'third  to  the  little  finger ;  the  middle  finger  being  ex- 
cluded. 

Relations. — By  their  palmar  surface  with  the  flexor  tendons  and  with 
the  deep  muscles  in  the  palm  of  the  hand.  By  their  dorsal  surface  with 
the  dorsal  interossei.  On  one  side  with  the  metacarpal  bone,  on  the  other 
with  the  corresponding  dorsal  interosseous. 

DORSAL  INTEROSSEI. — On  turning  to  the  dorsum  of  the  hand,  the  four 
dorsal  interossei  are  seen  in  the  four  spaces  bet\veen  the  metacarpal  bones. 
They  are  bipenniform  muscles  and  arise  by  two  heads,  from  the  adjoining 
sides  of  the  base  of  the  metacarpal  bones.  They  are  inserted  into  the  base 
of  the  first  phalanges,  and  aponeurosis  of  the  extensor  tendons. 

The  first  is  inserted  into  the  index  finger,  and  from  its  use  is  called 
abductor  indicis,|  the  second  and  third  are  inserted  into  the  middle  finger 
compensating  its  exclusion  from  the  palmar  group  ;  the  fourth  is  attached 
to  the  ring  finger ;  so  that  each  finger  is  provided  with  two  interossei, 
with  the  exception  of  the  little  finger,  as  may  be  shown  by  means  of  a 
table,  thus : — 

r  j     -c          \  one  dorsal  (abductor  indicis), 

J   &    '  £  one  palmar. 
Middle  finger,  two  dorsal. 

D.      £  (  one  palmar, 

Rmgnnger,  <          j       i 
'   (  one  dorsal. 

Little  finger,     remaining  palmar. 

Relations. — By  their  dorsal  surface  with  a  thin  aponeurosis  which  sepa- 
ates  them  from  the  tendons  on  the  dorsum  of  the  hand.    By  their  palmar 

•  Palmar  interossei.  1.  Adductor  indicis.  2.  Abductor  annularis.  3.  Interosseom 
auricularis. 

j-  Dorsal  interossei.  1.  Abductor  indicis.  2.  Abductor  medii.  3.  Adductor  medii. 
4.  Adductor  annularis. 

$  Homer  divides  this  muscle  and  calls  one  portion  of  it  abductor  indicis  and  the  other 
prior  indicis.  Wilson's  description  is  the  best,  as  it  makes  the  analogy  between  the  foot 
and  hand  complete,  whilst  there  is  a  great  discrepancy  in  Homer's  mode  of  describing 
them. — G. 

21  Q 


242  MUSCLES    OF   THE    LOWER    EXTREMITY. 

\ 

surface  with  the  muscles  and  tendons  in  the  palm  of  the  hand.  By  one 
side  with  the  metacarpal  bone  ;  by  the  other  with  the  corresponding  palmar 
interosseous.  The  abductor  indicis  is  in  relation  by  its  palmar  surface 
with  the  adductor  pollicis,  the  arteria  magna  pollicis  being  interposed. 
The  radial  artery  passes  into  the  palm  of  the  hand  between  the  two  heads 
of  the  first  dorsal  interosseous  muscle  and  the  perforating  branches  of  the 
deep  palmar  arch,  between  the  heads  of  the  other  dorsal  interossei. 

Actions, — The  actions  of  the  muscles  of  the  hand  are  expressed  in  their 
names.  Those  of  the  radial  region  belong  to  the  thumb,  and  provide  for 
three  of  its  movements,  abduction,  adduction,  and  flexion.  The  ulnar 
group,  in  like  manner,  are  subservient  to  the  same  motions  of  the  little 
finger,  and  the  interossei  are  abductors  and  adductors  of  the  several  fin- 
gers. The  lumbricales  are  accessory  in  their  actions  to  the  deep  flexors : 
they  were  called  by  the  earlier  anatomists,  fidicinii,  i.  e.  fiddlers'  muscles, 
from  an  idea  that  they  might  effect  the  fractional  movements  by  which  the 
performer  is  enabled  to  produce  the  various  notes  on  that  instrument. 

In  relation  to  the  axis  of  the  hand,  the  four  dorsal  interossei  are  abduc- 
tors, and  the  three  palmar,  adductors.  It  will  therefore  be  seen  that  each 
finder  is  provided  with  its  proper  adductor  and  abductor,  two  flexors,  and 
(with  the  exception  of  the  middle  and  ring  fingers)  two  extensors.  The 
thumb  has  moreover  a  flexor  and  extensor  of  the  metacarpal  bone ;  and 
the  little  finger  a  flexor  of  the  metacarpal  bone  without  an  extensor. 

MUSCLES    OF    THE    LOWER    EXTREMITY. 

The  muscles  of  the  lower  extremity  may  be  arranged  into  groups  cor- 
responding with  the  regions  of  the  hip,  thigh,  leg,  and  foot,  as  in  the  fol- 
lowing table : — 

HIP. 
Gluteal  Region. 

Gluteus  maximus,  Gluteus  medius, 

Gluteus  minimus,  Pyriformis, 

Gemellus  superior,  Obturator  internus, 

Gemellus  inferior,  Obturator  externus. 
Quadratus  femoris. 

THIGH. 

Anterior  Femoral  Region.  Internal  Femoral  Region. 

Tensor  vaginae  femoris,  Iliacus  internus, 

Sartorius,  Psoas  magnus, 

Rectus,  Pectineus, 

Vastus  internus,  Adductor  Inngus, 

V7astus  externus.  Adductor  brevis, 

Crureus.  Adductor  magnus, 

Gracilis. 

Posterior  Femoral  Region. 

Biceps, 

Semitendinosus, 

Semimembranosus. 


MUSCLES    OF   THE    LOWER   EXTREMITY,    ETC.  243 

LEG. 

interior  Tibial  Region.  Posterior  Tibial  Region. 

Tibialis  anticus,  Superficial  Group. 

Extensor  longus  digitorum,  Gastrocnemius, 

Peroneus  tertius,  Plantaris, 

Extensor  longus  pollicis.'  Soleus. 

Fibidar  Region.  Deep  [posterior]  Layer. 

Peroneus  longus,  Popliteus, 

Peroneus  brevis.  Flexor  longus  pollicis, 

Flexor  longus  digitorum, 
Tibialis  posticus. 

FOOT. 
Dorsal  Region. 

Extensor  brevis  digitoruhi, 
Interossei  dorsales. 

Plantar  Region. 
1st  Layer.  3d  Layer. 

Abductor  pollicis,  Flexor  brevis  pollicis, 

Abductor  minimi  digiti,  Adductor  pollicis, 

Flexor  brevis  digitorum.  Flexor  brevis  minimi  digiti, 

Transversus  pedis. 

2d  Layer.  &th  Layer. 

Musculus  accessorius,  Interossei  plantares. 

Lumbricales. 


GLUTEAL    REGION. 

Gluteus  maximus,  Obturator  internus, 

Gluteus  medius,  Gemellus  inferior, 

Gluteus  minimus,  Obturator  externus, 

Pyriformis,  Quadratus  femoris. 
Gemellus  superior, 

Dissection.  —  The  subject  being  turned  on  its  face,  and  a  block  placed 
beneath  the  os  pubis  to  support  the  pelvis,  the  student  commences  the 
dissection  of  this  region,  by  carrying  an  incision  from  the  apex  of  the 
coccyx  along  the  crest  of  the  ilium  to  its  anterior  superior  spinous  process ; 
or  vice  versa,  if  he  be  on  the  left  side.  He  then  makes  an  incision  from 
the  posterior  fifth  of  the  crest  of  the  ilium,  to  the  apex  of  the  trochanter 
major,  this  marks  the  upper  border  of  the  gluteus  maximus ;  and  a  third 
incision  from  the  apex  of  the  coccyx  along  the  fleshy  margin  of  the  lower 
border  of  the  gluteus  maximus,  to  the  outer  side  of  the  thigh,  about  four 
inches  below  the  apex  of  the  trochanter  major.  He  then  reflects  the  inte- 
gument, superficial  fascia,  and  deep  fascia,  which  latter  is  very  thin  over 
this  muscle,  from  the  gluteus  maximus,  following  rigidly  the  course  of  its 
fibres  ;  and  having  exposed  the  muscle  in  its  entire  extent,  he  dissects  the 
integument  and  superficial  fascia  from  off  the  deep  fascia  which  binds 
down  the  gluteus  medius,  the  other  portion  of  this  region. 


244 


MUSCLES    OF    THE    GLUTEAL    REGION. 


Fig.  129 .» 


The  GLUTEUS  MAXIMUS  (/Xouroj,  nates) 
is  the  thick,  fleshy  mass  of  muscle,  of  a 
quadrangular  shape,  which  forms  the  con- 
vexity of  the  nates.     In  structure,  it  is  ex- 
tremely coarse,  being  made  up  of  large 
fibres,  which  are  collected  into  fasciculi, 
and  these   again    into    distinct   muscular 
masses,  separated  by  deep   cellular  fur- 
rows.    It  arises  from  the  posterior  fifth  of 
the  crest  of  the  ilium,  from  the  posterior 
surface  of  the  sacrum  and  coccyx,  and 
from  the  great  sacro-ischiatic  ligament.    It 
passes  obliquely  outwards  and  downwards, 
to  be  inserted  into  the  rough  line  leading 
from   the   trochanter  major  to   the   linea 
aspera,  and  is  continuous  by  means  of  its 
tendon  with  the  fascia  lata  covering  the 
outer  side  of  the  thigh.     A  large  bursa  is 
situated  between  the  broad  tendon  of  this 
muscle  and  the  femur. 
Relations.  —  By  its  superficial  surface  with  a  thin  aponeurotic  fascia, 
which  separates  it  from  the  superficial  fascia  and  integument,  and  with 
the  vastus  externus,  a  bursa  being  interposed.     By  its  deep  surface  with 
the  gluteus  medius,  pyriformis,  gemelli,  obturator  internus,   quadratus 
femoris,  sacro-ischiatic  foramina,  great  sacro-ischiatic  ligament,  tuberosity 
of  the  ischium,  semimembranosus,  semitendinosus,  biceps,  and  adductor 
magnus ;  the  gluteal  vessels  and  nerves,  ischiatic  vessels  and  nerves,  and 
internal  pudic  vessels  and  nerve.     By  its  upper  border  it  overlaps  the 
gluteus  medius ;  and  by  the  lower  border  forms  the  lower  margin  of  the 
nates. 

The  gluteus  maximus  must  be  turned  down  from  its  origin,  in  order  to 
bring  the  next  muscle  into  view. 

The  GLUTEUS  MEDIUS  is  placed  in  front  of,  rather  than  beneath  the 
gluteus  maximus;  and  is  covered  in  by  a  process  of  the  deep  fascia, 
which  is  very  thick  and  dense.  It  arises  from  the  outer  lip  of  the  crest 
of  the  ilium  for  four-fifths  of  its  length,  from  the  surface  of  bone  between 
that  border  and  the  superior  curved  line  on  the  dorsum  ilii,  and  from  the 
dense  fascia  above-mentioned.  Its  fibres  converge  to  the  outer  part  of 
the  trochanter  major,  into  which  its  tendon  is  inserted. 

Relations. — By  its  superficial  surface  with  the  tensor  vaginse  femoris, 
gluteus  maximus,  and  its  fascia.  By  its  deep  surface  with  the  gluteus 
minimus,  and  gluteal  vessels  and  nerves.  By  its  lower  border  with  the 
pyriformis  muscle.  A  bursa  is  interposed  between  its  tendon  and  the 
upper  part  of  the  trochanter  major. 

*  The  deep  muscles  of  the  gluteal  region.  1.  The  external  surface  of  the  ilium.  2. 
The  posterior  surface  of  the  sacrum.  3.  The  posterior  sacro-iliac  ligaments.  4.  The 
tuberosity  of  the  ischium.  5.  The  great  or  posterior  sacro-ischiatic  ligament.  6.  The 
lesser  or  anterior  sacro-ischiatic  ligament.  7.  The  trochanter  major.  8.  The  gluteus 
minimus.  9.  The  pyriformis.  10.  The  gemellus  superior.  11.  The  obturator  internus 
muscle,  passing  out  of  the  lesser  sacro-ischiatic  foramen.  12.  The  gemellus  inferior. 
J3.  The  quadratus  femoris.  14,  The  upper  part  of  the  adductor  magnus.  15.  The 
rastus  externus.  16.  The  biceps.  17.  The  gracilis.  18.  The  semitendinosus. 


OBTURATOR  INTERNUS.  045 

This  muscle  should  now  be  removed  from  its  origin  and  turned  down 
so  as  to  expose  the  next,  which  is  situated  beneath  it. 

The  GLUTEUS  MINIMUS  is  a  radiated  muscle,  arising  from  the  surface 
of  the"  dorsum  ilii,  between  the  superior  and  inferior  curved  lines ;  its 
fibres  converge  to  the  anterior  border  of  the  trochanter  major,  into  which 
it  is  inserted  by  means  of  a  rounded  tendon.  There  is  no  distinct  line  of 
Reparation  between  the  gluteus  medius  and  minimus  anteriorly. 

Relations.  —  By  its  superficial  surface  with  the  gluteus  medius,  and 
gluteal  vessels.  By  its  deep  surface  with  the  surface  of  the  ilium,  the 
long  tendon  of  the  rectus  femoris,  and  the  capsule  of  the  hip  joint.  A 
bursa  is  interposed  between  the  tendon  of  the  muscle  and  the  trochanter. 

The  PYRIFORMIS  muscle  (pyrum,  a  pear,  i.  e.  pear-shaped)  arises  from 
the  anterior  surface  of  the  sacrum,  by  little  slips  that  are  interposed  be- 
tween the  first  and  fourth  anterior  sacral  foramina,  and  from  the  adjoining 
surface  of  the  ilium.  It  passes  out  of  the  pelvis,  through  the  great  sacro- 
ischiatic  foramen,  and  is  inserted  by  a  rounded  tendon  into  the  trochanteric 
fossa  of  the  femur. 

Relations.  —  By  its  superficial  or  external  surface  with  the  sacrum  and 
gluteus  maximus.  By  its  deep  or  pelvic  surface  with  the  rectum,  the 
sacral  plexus  of  nerves,  the  branches  of  the  internal  iliac  artery,  the  great 
sacro-ischiatic  notch,  and  the  capsule  of  the  hip  joint.  By  its  upper  border 
with  the  gluteus  medius  and  gluteal  vessels  and  nerves.  By  its  lower 
border  with  the  gemellus  superior,  ischiatic  vessels  and  nerves,  and  internal 
pudic  vessels  and  nerve. 

The  GEMELLUS  SUPERIOR  (gemellus,  double,  twin)  is  a  small  slip  of 
muscle,  situated  immediately  below  the  pyriformis ;  it  arises  from  the 
spine  of  the  ischium,  and  is  inserted  into  the  upper  border  of  the  tendon 
of  the  obturator  internus,  and  into  the  trochanteric  fossa  of  the  femur. 
The  gemellus  superior  is  not  unfrequently  wanting. 

Relations.  —  By  its  superficial  surface  with  the  gluteus  maximus,  the 
ischiatic  vessels  and  nerves,  and  internal  pudic  vessels  and  nerve.  By  its 
deep  surface  with  the  pelvis,  and  capsule  of  the  hip  joint. 

The  OBTURATOR  INTERNUS  arises  from  the  inner  surface  of  the  anterior 
wall  of  the  pelvis,  being  attached  to  the  margin  of  bone  around  the  obtu- 
rator foramen,  and  to  the  obturator  membrane.  It  passes  out  of  the  pelvis 
through  the  lesser  sacro-ischiatic  foramen,  and  is  inserted  by  a  flattened 
tendon  into  the  trochanteric  fossa  of  the  femur.  The  lesser  sacro-ischiatic 
notch,  over  which  this  muscle  plays  as  through  a  pulley,  is  faced  with 
cartilage,  and  provided  with  a  synovial  bursa  to  facilitate  its  movements. 
The  tendon  of  the  obturator  is  supported  on  each  side  by  the  two  gemelli 
muscles  (hence  their  names),  which  are  inserted  into  the  sides  of  the  ten- 
don, and  appear  to  be  auxiliaries  or  superadded  portions  of  the  obturator 
internus. 

Relations. — By  its  superficial  or  posterior  surface  with  the  internal  pudic 
vessels  and  nerve,  the  obturator  fascia,  which  separates  it  from  the  levator 
ani  and  viscera  of  the  pelvis,  the  sacro-ischiatic  ligaments,  gluteus  maxi- 
mus, and  ischiatic  vessels  and  nerves  By  its  deep  or  anterior  surface 
with  the  obturator  membrane  and  the  margin  of  bone  surrounding  it,  the 
cartilaginous  pulley  of  the  lesser  ischiatic  foramen,  ihe  external  surface  of 
the  pelvis,  and  the  capsular  ligament  of  the  hip  joint.  By  its  upper  border,, 
within  the  pelvis,  with  the  obturator  vessels  and  nerve ;  externally  to  the 
21* 


246  ANTERIOR   FEMORAL    REGION. 

pelvis,  with  the  gemellus  superior.    By  its  lower  border  witn  the  geinellus 
inferior. 

The  GEMELLUS  INFERIOR  arises  from  the  posterior  point  of  the  tuberosity 
of  the  ischium,  and  is  inserted  into  the  lower  border  of  the  tendon  of  thn 
obturator  internus,  and  into  the  trochanteric  fossa  of  the  femur. 

Relations.  —  By  its  superficial  surface  with  the  gluteus  maximus,  and 
ischiatic  vessels  and  nerves.  By  its  deep  surface  with  the  external  surface 
of  the  pelvis,  and  capsule  of  the  hip  joint.  By  its  upper  border  with  the 
tendon  of  the  obturator  internus.  By  its  lower  border  with  the  tendon  of 
the  obturator  externus  and  quadratus  femoris. 

In  this  region  the  tendon  only  of  the  obturator  externus  can  be  seen, 
situated  deeply  between  the  gemellus  inferior  and  the  upper  border  of  the 
quadratus  femoris.  To  expose  this  muscle  fully,  it  is  necessary  to  dissect 
it  from  the  anterior  part  of  the  thigh,  after  ithe  removal  of  the  pectineus, 
adductor  longus  and  adductor  brevis  muscles. 

The  OBTURATOR  EXTERNUS  muscle  (obturare,  to  stop  up)  arises  from 
the  obturator  membrane,  and  from  the  surface  of  bone  immediately  sur- 
rounding it  anteriorly,  viz.  from  the  ramus  of  the  os  pubis  and  ischium : 
its  tendon  passes  behind  the  neck  of  the  femur,  to  be  inserted  with  the 
external  rotator  muscles,  into  the  trochanteric  fossa  of  the  femur. 

Relations. — By  its  superficial  or  anterior  surface  with  the  tendon  of  the 
psoas  and  iliacus,  pectineus,  adductor  brevis  and  magnus,  the  obturator 
vessels  and  nerve.  By  its  deep  or  posterior  surface  with  the  obturatoi 
membrane  and  the  margin  of  bone  which  surrounds  it,  the  lower  part  ot 
the  capsule  of  the  hip  joint  and  the  quadratus  femoris. 

The  QUADRATUS  FEMORIS  (square-shaped)  arises  from  the  external  bor 
der  of  the  tuberosity  of  the  ischium,  and  is  inserted  into  a  rough  line  on 
the  posterior  border  of  the  trochanter  major,  which  is  thence  named  linea 
quadrati. 

Relations. — By  its  posterior  surface  with  the  gluteus  maximus,  and  is- 
chiatic vessels  and  nerves.  By  its  anterior  surface  with  the  tendon  of  the 
obturator  externus,  and  trochanter  minor,  a  synovial  bursa  often  separating 
it  from  the  latter.  By  its  upper  border  with  the  gemellus  inferior ;  and  by 
the  lower  border  with  the  adductor  magnus. 

Actions. — The  glutei  muscles  are  abductors  of  the  thigh,  when  they 
take  their  fixed  point  from  the  pelvis.  Taking  their  fixed  point  from  the 
thigh,  they  steady  the  pelvis  on  the  head  of  the  femur ;  this  action  is  pe- 
culiarly obvious  in  standing  on  one  leg ;  they  assist  also  in  carrying  the 
leg  forward,  in  progression.  The  gluteus  minimus  being  attached  to  the 
anterior  border  of  the  trochanter  major,  rotates  the  limb  slightly  inwards. 
The  gluteus  medius  and  maximus,  from  their  insertion  into  the  posterior 
aspect  of  the  bone,  rotate  the  limb  outwards ;  the  latter  is,  moreover,  a 
tensor  of  the  fascia  of  the  thigh.  The  other  muscles  rotate  the  limb  out- 
wards, everting  the  knee  and  foot ;  hence  they  are  named  external  rotators. 

interior  Femoral  Region. 

Tensor  vaginae  femoris,  Vastus  internus, 

Sartorius,  Vastus  externus, 

Rectus,  Crureus. 

Dissection.— Make  an  incision  along  the  line  of  Poupart's  ligament, 
*rom  the  anterior  superior  spinous  process  of  the  ilium  to  the  spine  of  the 


Fig.  130.* 


TENSOR   VAGINAE    FEMORIS SARTORIUS.  217 

os  pubis ;  and  a  second,  from  the  middle  of  the  preceding  down  the  inner 
side  of  the  thigh,  and  across  the  inner  condyle  of  the  femur,  to  the  head 
of  the  tibia,  where  it  may  be  bounded  by  a  transverse  incision  Turn 
back  the  integument  from  the  whole  of  this  region,  and  examine  the  super- 
ficial fascia ;  which  is  next  to  be  removed  in  the  same  manner.  After  the 
deep  fascia  has  been  well  considered,  it  is  likewise  to  be  removed,  by  dis- 
secting it  off  in  the  course  of  the  fibres  of  the  muscles.  As  it  might  not 
be  convenient  to  the  junior  student  to  expose  so  large  a  surface  at  once  as 
ordered  in  this  dissection,  the  vertical  incision  may  be  crossed  by  one  or 
two  transverse  incisions,  as  may  be  deemed  most  proper. 

The  TENSOR  VAGINJE  FEMORIS  (stretcher  of  the  sheath  of  the  thigh)  is  a 
short  flat  muscle,  situated  on  the  outer  side  of  the  hip.  It  arises  from  the 
crest  of  the  ilium,  near  its  anterior  superior  spinous  process,  and  is  inserted 
between  two  layers  of  the  fascia  lata  at  about  one-fourth  down  the  thigh. 

Relations.— r-By  its  superficial  surface  with  the  fascia 
lata  and  integument.  By  its  deep  surface  with  the  in- 
ternal layer  of  the  fascia  lata,  gluteus  medius,  rectus 
and  vastus  externus.  By  its  inner  border  near  its  ori- 
gin with  the  sartorius. 

The  SARTORIUS  (tailor's  muscle)  is  a  long  riband- 
like  muscle,  arising  from  the  anterior  superior  spinous 
process  of  the  ilium,  and  from  the  notch  immediately 
below  that  process ;  it  crosses  obliquely  the  upper 
third  of  the  thigh,  descends  behind  the  inner  condyle 
of  the  femur,  and  is  inserted  by  an  aponeurotic  expan- 
sion into  the  inner  tuberosity  of  the  tibia.  This  ex- 
pansion covers  in  the  insertion  of  the  tendons  of  the 
gracilis  and  semitendinosus  muscles.  The  inner  bor- 
der of  the  sartorius  muscle  is  the  guide  to  the  opera- 
tion for  tying  the  femoral  artery  in  the  middle  of  its 
course. 

Relations. — By  its  superficial  surface  with  the  fascia 
lata  and  some  cutaneous  nerves.  By  its  deep  surface 
with  the  psoas  and  iliacus,  rectus,  sheath  of  the  femo- 
ral vessels  and  saphenous  nerves,  vastus  internus,  ad- 
ductor longus,  adductor  magnus,  gracilis,  long  saphe- 
nous nerve,  internal  lateral  ligament  of  the  knee  joint. 
By  its  expanded  insertion  with  the  tendons  of  the  gra- 
cilis and  semi-tendinosus,  a  synovia!  bursa  being  inter- 
posed. At  the  knee  joint  its  posterior  border  is  in 
relation  with  the  internal  saphenous  vein.  At  the  up- 
per third  of  the  thigh  the  sartorius  forms,  with  the  lower 
border  of  the  adductor  longus,  an  isosceles  triangle, 
whereof  the  base  corresponds  with  Poupart's  ligament.  A  perpendicular 
line  drawn  from  the  middle  of  the  base  of  the  apex  of  this  triangle,  imme- 
diately overlies  the  femoral  artery  with  its  sheath. 

*  The  muscles  of  the  anterior  femoral  region.  1.  The  crest  of  the  ilium.  2.  Its  ati 
terior  superior  spinous  process.  3.  The  gluteus  medius.  4.  The  tensor  vaginaa  femoris, 
its  insertion  into  the  fascia  lata  is  shown  inferiorly.  5.  The  sartorius.  6.  The  rectum 
7.  The  vastus  externus.  8.  The  vastus  internus.  9.  The  patella.  10.  The  iliacus  HI 
ternus.  11.  The  psoas  magnus.  12.  The  pectineus.  13.  The  adductor  longus.  14 
Part  of  the  adductor  magnus.  15.  Thn  gracilis. 


248  VASTUS    INTERNUS — CRUREUS. 

The  RECTUS  (straight)  muscle  is  fusiform  in  its  shape  and  bipenniform 
in  the  disposition  of  its  fibres.  It  arises  by  two  round  tendons,  one  from 
the  anterior  inferior  spinous  process  of  the  ilium,  the  other  from  the  upper 
lip  of  the  acetabulum ;  and  is  inserted  by  a  broad  and  strong  tendon,  into 
the  upper  border  of  the  patella.  It  is  more  correct  to  consider  the  patella 
as  a  sesamoid  bone,  developed  within  the  tendon  of  the  rectus  ;  and  the 
hgamentum  patellae  as  the  continuation  of  the  tendon  to  its  insertion  into 
the  tubercle  of  the  tibia. 

Relations. — By  its  superficial  surface  with  the  gluteus  medius,  psoas 
and  iliacus,  sartorius ;  and,  for  the  lower  three-fourths  of  its  extent,  with 
the  fascia  lata.  By  its  deep  surface  with  the  capsule  of  the  hip  joint,  the 
external  circumflex  vessels,  crureus,  and  vastus  internus  and  externus. 

The  rectus  must  now  be  divided  through  its  middle,  and  the  two  ends 
turned  aside,  to  bring  clearly  into  view  the  next  muscles. 

The  three  next  muscles  are  generally  considered  collectively  under  the 
name  of  triceps  extensor  cruris.  Adopting  this  view,  the  muscle  surrounds 
the  whole  of  the  femur,  excepting  the  rough  line  (linea  aspera)  upon  its 
posterior  aspect.  Its  division  into  three  parts  is  not  well  defined ;  the 
fleshy  mass  upon  each  side  being  distinguished  by  the  names  of  vastus 
internus  and  externus,  the  middle  portion  by  that  of  crureus. 

The  VASTUS  EXTERNUS,  narrow  below  and  broad  above,  arises  from 
the  outer  border  of  the  patella,  and  is  inserted  into  the  femur  and  outer 
side  of  the  linea  aspera,  as  high  as  the  base  of  the  trochanter  major. 

Relations. — By  its  superficial  surface  with  the  fascia  lata,  rectus,  biceps, 
semi-membranosus  and  gluteus  maximus,  a  synovial  bursa  being  inter- 
posed between  it  and  the  latter.  By  its  deep  surface  with  the  crureus  and 
femur. 

The  VASTUS  INTERNUS,  broad  below  and  narrow  above,  arises  from 
the  inner  border  of  the  patella,  and  is  inserted  into  the  femur  and  inner 
side  of  the  linea  aspera  as  high  up  as  the  anterior  intertrochanteric  line. 

Relations. — By  its  superficial  surface  with  the  psoas  and  iliacus,  rectus, 
sartorius,  femoral  artery  and  vein  and  saphenous  nerves,  pectineus,  ad- 
ductor longus,  brevis,  and  magnus,  and  fascia  lata.  By  its  deep  surface 
with  the  crureus  and  femur. 

The  CRUREUS  (crus,  the  leg)  arises  from  the  upper  border  of  the  patella, 
and  is  inserted  into  the  front  aspect  of  the  femur,  as  high  as  the  anterior 
intertrochanteric  line.  When  the  crureus  is  divided  from  its  insertion,  a 
small  muscular  fasciculus  is  often  seen  upon  the  lower  part  of  the  femur, 
which  is  inserted  into  the  pouch  of  synovial  membrane,  that  extends  up- 
wards from  the  knee  joint,  behind  the  patella.  This  is  named,  from  its 
situation,  sub-crureus,  and  would  seem  to  be  intended  to  support  the 
synovial  membrane. 

Relations.  —  By  its  superficial  surface  with  the  external  circumflex 
vessels,  the  rectus,  vastus  internus  and  externus.  By  its  deep  surface  with 
the  femur,  the  sub-crureus,  and  synovial  membrane  of  the  knee  joint. 

Actions.  —  The  tensor  vaginae  femoris  renders  the  fascia  lata  tense,  and 
slightly  inverts  the  limb.  The  sartorius  flexes  the  leg  upon  the  thigh,  and, 
continuing  to  act,  the  thigh  upon  the  pelvis,  at  the  same  time  carrying  the 

*  across  that  of  the  opposite  side,  into  the  position  in  which  tailors  sit ; 
hence  its  name.  Taking  its  fixed  point  from  below,  it  assists  the  extensor 
muscles  in  steadying  the  leg,  for  the  support  of  the  trunk.  The  other  four 
muscles  have  been  collectively  named  quadriceps  extensor,  from  their 


INTERNAL    FEMORAL    REGION.  249 

similarity  of  action.  They  extend  the  leg  upon  the  thigh,  and  obtain  a 
great  increase  of  power  by  their  attachment  to  the  patella,  \vhich  acts  as  a 
fulcrum.  Taking  their  fixed  point  from  the  tibia,  they  steady  the  femur 
upon  the  leg,  and  the  rectus,  by  being  attached  to  the  pelvis,  serves  to 
balance  the  trunk  upon  the  lower  extremity. 

Internal  Femoral  Region. 

Iliacus  internus,  Adductor  brevis, 

Psoas  magnus,  Adductor  magnus, 

Pectineus,  Gracilis. 
Adductor  longus, 

Dissection.  —  These  muscles  are  exposed  by  the  removal  of  the  inner 
flap  of  integument  recommended  in  the  dissection  of  the  anterior  femoral 
region.  The  iliacus  and  psoas  arising  from  within  the  abdomen,  can  only 
be  seen  in  their  entire  extent  after  the  removal  of  the  viscera  from  that 
cavity. 

The  ILIACUS  INTERNUS  is  a  flat  radiated  muscle.  It  arises  from  the 
whole  extent  of  the  inner  concave  surface  of  the  ilium ;  and,  after  joining 
with  the  tendon  of  the  psoas,  is  inserted  into  the  trochanter  minor  of  the 
femur.  A  few  fibres  of  this  muscle  are  derived  from  the  base  of  the  sa- 
crum, and  others  from  the  capsular  ligament  of  the  hip  joint. 

Relations. — By  its  anterior  surface,  within  the  pelvis,  with  the  external 
cutaneous  nerve,  and  with  the  iliac  fascia,  which  separates  the  muscle 
from  the  peritoneum,  on  the  right  from  the  caecum,  and  on  the  left  from 
the  sigmoid  flexure  of  the  colon ;  externally  to  the  pelvis  with  the  fascia 
lata,  rectus,  and  sartorius.  By  its  posterior  surface  with  the  iliac  fossa, 
margin  of  the  pelvis,  and  with  the  capsule  of  the  hip  joint,  a  synovial 
bursa  of  large  size  being  interposed,  which  is  sometimes  continuous  with 
the  synovial  membrane  of  the  articulation.  By  its  inner  border  with  the 
psoas  magnus  and  crural  nerve. 

The  PSOAS  MAGNUS  (-^o'a,  lumbus,  a  loin),  situated  by  the  side  of  the 
vertebral  column  in  the  loins,  is  a  long  fusiform  muscle.  It  arises  from 
the  intervertebral  substances,  part  of  the  bodies  and  bases  of  the  trans- 
verse processes,  and  from  a  series  of  tendinous  arches,  thrown  across  the 
constricted  portion  of  the  last  dorsal  and  four  upper  lumbar  vertebrae. 
These  arches  are  intended  to  protect  the  lumbar  arteries  and  sympathetic 
filaments  of  nerves  from  pressure,  in  their  passage  beneath  the  muscle. 
From  this  extensive  origin,  the  muscle  passes  along  the  margin  of  the 
brim  of  the  pelvis,  and  beneath  Poupart's  ligament,  to  its  insertion.  The 
tendon  of  the  psoas  magnus  unites  with  that  of  the  iliacus,  and  the  con- 
joined tendon  is  inserted  into  the  posterior  part  of  the  trochanter  minor,  a 
bursa  being  interposed. 

Relations.  —  By  its  anterior  surface,  with  the  ligamentum  arcuatum  in- 
ternum  of  the  diaphragm,  the  kidney,  the  psoas  parvus,  genito-crural 
nerve,  sympathetic  nerve,  its  proper  fascia,  the  peritoneum  and  colon,  and 
along  its  pelvic  border  with  the  common  and  external  iliac  artery  and 
vein.  By  its  posterior  surface,  with  the  lumbar  vertebras,  the  lumbar  ar- 
teries, quadratus  lumborum,  from  which  it  is  separated  by  the  anterioi 
layer  of  the  aponeurosis  of  the  transversalis,  and  with  the  crural  nerve, 
which,  near  Poupart's  ligament,  gets  to  its  outer  side.  The  lumbar  plexus 
of  nerves  is  situated  in  the  substance  of  tlte  posterior  part  of  the  muscle 


250  ADDUCTOR   BREVIS. 

In  the  thigh,  the  muscle  is  in  relation  with  the  fascia  lata  in  front ;  the 
border  of  the  pelvis  and  hip  joint,  from  which  it  is  separated  by  the  syno- 
vial  membrane,  common  to  it  and  the  preceding  muscle,  behind  ;  with  the 
crural  nerve  and  iliacus,  to  the  outer  side ;  and  with  the  femoral  artery, 
by  which  it  is  slightly  overlaid,  to  the  inner  side. 

The  PECTINEUS  is  a  flat  and  quadrangular  muscle ;  it  arises  from  the 
pectineal  line  (pecten,  a  crest)  of  the  os  pubis,  and  from  the  surface  of 
bone  in  front  of  that  bone.  It  is  inserted  into  the  line  leading  from  the 
anterior  intertrochanteric  line  to  the  linea  aspera  of  the  femur. 

Relations. — By  its  anterior  surface,  with  the  pubic  portion  of  the  fascia 
lata,  which  separates  it  from  the  femoral  artery  and  vein  and  internal  sa- 
phenous  vein,  and  lower  down  with  the  profunda  artery.  By  its  posterior 
surface,  with  the  capsule  of  the  hip  joint,  and  with  the  obturator  externus  and 
adductor  brevis,  the  obturator  vessels  being  interposed.  By  its  external 
border,  with  the  psoas,  the  femoral  artery  resting  upon  the  line  of  interval. 
By  its  internal  border,  with  the  outer  edge  of  the  adductor  longus.  Ob- 
turator hernia  is  situated  directly  behind  this  muscle,  which  forms  one  of 
its  coverings. 

The  ADDUCTOR  LONGUS  (adducere,  to  draw  to),  the  most  superficial  of 
the  three  adductors,  arises,  by  a  round  and  thick  tendon,  from  the  front 
surface  of  the  os  pubis,  immediately  below  the  angle ;  and  assuming  a 
flattened  and  expanded  form  as  it  descends,  is  inserted  into  the  middle 
third  of  the  linea  aspera. 

Relations. — By  its  anterior  surface,  with  the  pubic  portion  of  the  fascia 
lata,  and  near  its  insertion  with  the  femoral  artery  and  vein.  By  its  pos- 
terior surface,  with  the  adductor  brevis  and  magnus,  the  anterior  branches 
of  the  obturator  vessels  and  nerves,  and  near  its  insertion  with  the  pro- 
funda artery  and  vein.  By  its  outer  border,  with  the  pectineus ;  and  by 
the  inner  border,  with  the  gracilis. 

The  pectineus  must  be  divided  near  its  origin  and  turned  outwards,  and 
the  adductor  longus  through  its  middle,  turning  its  ends  to  either  side,  to 
bring  into  view  the  adductor  brevis. 

The  ADDUCTOR  BREVIS,  placed  beneath  the  pectineus  and  adductor 
longus,  is  fleshy,  and  thicker  than  the  adductor  longus  ;  it  arises  from  the 
body  and  rarnus  of  the  os  pubis,  and  is  inserted  into  the  upper  third  of  the 
linea  aspera. 

Relations. — By  its  anterior  surface,  with  the  pectineus,  adductor  longus, 
«md  anterior  branches  of  the  obturator  vessels  and  nerve.  By  its  posterior 
surface,  with  the  adductor  magnus,  and  posterior  branches  of  the  obturator 
vessels  and  nerve.  By  its  outer  border,  with  the  obturator  externus,  and 
conjoined  tendon  of  the  psoas  and  iliacus.  By  its  inner  border,  with  the 
gracilis  and  adductor  magnus.  The  adductor  brevis  is  pierced  near  its 
insertion  by  the  middle  perforating  artery. 

The  adductor  brevis  may  now  be  divided  from  its  origin  and  turned 
outwards,  or  its  inner  two-thirds  may  be  cut  away  entirely,  when  the  ad- 
ductor magnus  muscle  will  be  exposed  in  its  entire  extent. 

tThe  ADDUCTOR  MAGNUS  is  a  broad  triangular  muscle,  forming  a  septum 
of  division  between  the  muscles  situated  on  the  anterior  and  those  on  the 
posterior  aspect  of  the  thigh.  It  arises,  by  fleshy  fibres,  from  the  ramus 
of  the  pubes  and  ischium,  and  from  the  side  of  the  tuber  ischii ;  and  radi- 
ating in  its  passage  outwards,  is  inserted  into  the  whole  length  of  the  linea 
«spen.,  and  inner  condyle  of  the  femur.  The  adductor  magnus  is  pierced 


POSTERIOR    FEMORAL    REGIOX.  251 

by  five  openings :  the  three  superior,  for  the  three  perforating  arteries ; 
and  the  fourth,  for  the  termination  of  the  profunda.  The  fifth  is  the  large 
oval  opening,  in  the  tendinous  portion  of  the  muscle,  that  gives  passage 
to  the  femoral  vessels. 

Relations. — By  its  anterior  surface,  with  the  pectineus,  adductor  brevis, 
adductor  longus,  femoral  artery  and  vein,  profunda  artery  and  vein,  with 
their  branches,  and  with  the  posterior  branches  of  the  obturator  vessels  and 
nerve.  By  its  posterior  surface,  with  the  semi-tendinosus,  semi-membra- 
nosus,  biceps,  and  gluteus  maximus.  By  its  inner  border,  with  the  gra- 
cilis  and  sartorius.  By  its  upper  border,  with  the  obturator  externus  and 
quadratus  femoris. 

The  GRACILIS  (slender)  is  situated  along  the  inner  border  of  the  thigh. 
It  arises  by  a  broad,  but  very  thin  tendon,  from  the  body  of  the  os  pubis, 
along  the  edge  of  the  symphysis,  and  from  the  margin  of  the  ramus  of  the 
pubes  and  ischium;  and  is  inserted,  by  a  rounded  tendon,  into  the  inner 
tuberosity  of  the  tibia,  beneath  the  expansion  of  the  sartorius. 

Relations.  — By  its  inner  or  superficial  surface,  with  the  fascia  lata,  and 
below,  with  the  sartorius  and  internal  saphenous  nerve ;  the  internal  sa- 
phenous  vein  crosses  it,  lying  superficially  to  the  fascia  lata.  By  its  outer 
or  deep  surface,  with  the  adductor  longus,  brevis,  and  magnus,  and  the 
internal  lateral  ligament  of  the  knee  joint,  from  which  it  is  separated  by  a 
synovia!  bursa,  common  to  the  tendons  of  the  gracilis  and  semi-tendinosus. 

Actions. — The  iliacus,  psoas,  pectineus,  and  adductor  longus  muscles 
bend  the  thigh  upon  the  pelvis,  and,  at  the  same  time,  from  the  obliquity 
of  their  insertion  into  the  lesser  trochanter  and  linea  aspera,  rotate  the  en- 
tire limb  outwards ;  the  pectineus  and  adductors  adduct  the  thigh  power- 
fully ;  and  from  the  manner  of  their  insertion  into  the  linea  aspera,  they 
assist  in  rotating  the  limb  outwards.  The  gracilis  is  likewise  an  adductor 
of  the  thigh  ;  but  contributes  also  to  the  flexion  of  the  leg,  by  its  attach- 
ment to  the  inner  tuberosity  of  the  tibia. 

Posterior  Femoral  Region. 
Biceps,         Semi-tendinosus,         Semi-membranosus. 

Dissection.^ — Remove  the  integument  and  fascia  on  the  posterior  part 
of  the  thigh  by  two  flaps,  as  on  the  anterior  region,  and  turn  aside  the  glu- 
teus maximus  from  the  upper  part ;  the  muscles  may  then  be  examined. 

The  BICEPS  FEMORIS  (bis,  double,  xspaXi?,  head)  arises  by  two  heads, 
one  by  a  common  tendon  with  the  serni-tendinosus ;  the  other  muscular 
and  much  shorter,  from  the  lower  two-thirds  of  the  external  border  of  the 
linea  aspera.  This  muscle  forms  the  outer  hamstring,  and  is  inserted  by  a 
strong  tendon  into  the  head  of  the  fibula ;  a  portion  of  the  tendon  is  con- 
tinued downwards  into  the  fascia  of  the  leg,  and  another  is  attached  to  the 
outer  tuberosity  of  the  tibia. 

Relations. — By  its  superficial  or  posterior  surface  with  the  gluteus  maxi- 
mus and  fascia  lata.  By  its  deep  or  anterior  surface  with  the  semi-mem- 
branosus,  adductor  magnus,  vastus  externus,  the  great  sciatic  nerve,  pop- 
liteal artery  and  vein,  and  near  its  insertion  with  the  external  head  of  the 
gastrocnemius,  and  plantaris.  By  its  inner  border  with  the  semi-tendi- 
nosus, and  in  the  popliteal  space  with  the  popliteal  artery  and  vein. 

The  SEMI-TENDINOSUS,  remarkable  for  its  long  tendon,  arises  in  common 
with  the  long  head  of  the  biceps,  from  the  tuberosity  of  the  ischium  ;  *he 


252 


SEMI-MEMBRANOSUS. 


Fig.  131.* 


two  muscles  being  closely  united  for  several  inches  below  their  origin,     ft 
is  inserted  into  the  inner  tuberosity  of  the  tibia. 

Relations. — By  its  superficial  surface  with  the  glu- 
teus  maximus,  fascia  lata,  and  at  its  insertion  with  the 
synovia!  bursa  which  separates  its  tendon  from  the  ex- 
pansion of  the  sartorius.  By  its  deep  surface  with  the 
semi-membranosus,  adductor  magnus,  internal  head 
of  the  gastrocnemius,  and  internal  lateral  ligament  of 
the  knee  joint,  the  synovial  bursa  common  to  it  and 
the  tendon  of  the  gracilis  being  interposed.  By  its 
inner  border  with  the  gracilis ;  and  by  its  outer  border 
with  the  biceps. 

These  two  muscles  must  be  dissected  from  the  tube- 
rosity of  the  ischium,  to  bring  into  view  the  origin  of 
the  next. 

The  SEMI-MEMBRANOSUS,  remarkable  for  the  tendi- 
nous expansion  upon  its  anterior  and  posterior  surface, 
arises  from  the  tuberosity  of  the  ischium,  in  front  of 
the  common  origin  of  the  two  preceding  muscles.  It 
is  inserted  into  the  posterior  part  of  the  inner  tuberosity 
of  the  tibia ;  at  its  insertion  the  tendon  splits  into  three 
portions,  one  of  which  is  inserted  in  a  groove  on  the 
inner  side  of  the  head  of  the  tibia,  beneath  the  internal 
lateral  ligament.  The  second  is  continuous  with  an 
aponeurotic  expansion  that  binds  down  the  popliteus 
muscle,  the  popliteal  fascia ;  and  the  third  turns  up- 
wards and  outwards  to  the  external  condyle  of  the 
femur,  forming  the  middle  portion  of  the  posterior 
ligament  of  the  knee  joint  (ligamentum  posticum 
Winslowii). 

The  tendons  of  the  last  two  muscles,  viz.  the  semi-tendinosus  and 
semi-membranosus,  with  those  of  the  gracilis  and  sartorius,  form  the 
inner  hamstring. 

Relations, — By  its  superficial  surface  with  the  gluteus  maximus,  biceps, 
semi-tendinosus,  fascia  lata,  and  at  its  insertion  with  the  tendinous  expan- 
sion of  the  sartorius.  By  its  deep  surface  with  the  quadratus  femoris,  ad- 
ductor magnus,  internal  head  of  the  gastrocnemius,  the  knee  joint,  from 
which  it  is  separated  by  a  synovial  membrane,  and  the  popliteal  artery 
and  vein.  By  its  inner  border  with  the  gracilis.  By  its  outer  border  with 
the  great  ischiatic  nerve,  and  in  the  popliteal  space  with  the  popliteal 
artery  and  vein. 

If  the  semi-membranosus  muscle  be  turned  down  from  its  origin,  the 
student  will  bring  into  view  the  broad  and  radiated  expanse  of  the  adduc- 
tor magnus,  upon  which  the  three  flexor  muscles  above  described  rest. 
•fictions.  —  These  three  hamstring  muscles  are  the  direct  flexors  of  the 

'The  muscles  of  the  posterior  femoral  and  gluteal  region.  1.  The  gluteus  medius. 
2.  The  gluteus  maximus.  3.  The  vastus  externus,  covered  in  by  fascia  lata.  4.  The 
long  head  of  the  biceps.  5.  Its  short  head.  6.  The  semi-tendinosus.  7.  The  semi 
aiembranosus.  8.  The  gracilis.  9.  A  part  of  the  inner  border  of  the  adductor  magnus. 
'0.  The  edge  of  the  sartorius.  11.  The  popliteal  space.  12.  The  gastrocnemius 
muscle;  its  two  heads.  The  tendon  of  the  biceps  forms  the  outer  hamstring;  and  the 
•artonus  with  the  tendons  of  the  gracilis,  semi-tendinosus,  and  semi-membranosus,  tho 
inner  hamstring. 


ANTERIOR    TIBIAL    REGION. 


253 


leg  upon  the  thigh  ;  and  by  taking  their  origin  from  below,  they  balance 
the  pelvis  on  the  lower  extremities.  The  biceps,  from  the  obliquity  of  its 
direction,  everts  the  leg  when  partially  flexed,  and  the  semi-tendinosus 
turns  the  leg  inwards  when  in  the  same  state  of  flexion. 

Anterior  Tibial  Region.  Fig.  132.* 

Tibialis  anticus, 
Extensor  longus  digitorum, 
Peroneus  tertius, 
Extensor  proprius  pollicis. 

Dissection. — The  dissection  of  the  anterior  tibial 
region  is  to  be  commenced  by  carrying  an  incision 
along  the  middle  of  the  leg,  midway  between  the 
tibia  and  the  fibula,  from  the  knee  to  the  ankle, 
and  bounding  it  inferiorly  by  a  transverse  incision 
extending  from  one  malleolus  to  the  other.  And 
to  expose  the  tendons  on  the  dorsum  of  the  foot,  »!) 
the  longitudinal  incision  may  be  carried  onwards  to 
the  outer  side  of  the  base  of  the  great  toe,  and  be 
terminated  by  another  incision  directed  across  the 
heads  of  the  metatarsal  bones. 

The  TIBIALIS  ANTICUS  muscle  (flexor  tarsi  tibialis) 
arises  from  the  upper  two-thirds  of  the  tibia,  from 
the  interosseous  membrane,  and  from  the  deep 
fascia ;  its  tendon  passes  through  a  distinct  sheath 
in  the  annular  ligament,  and  is  inserted  into  the 
inner  side  of  the  internal  cuneiform  bone,  and  base 
of  the  metatarsal  bone  of  the  great  toe. 

Relations.  —  By  its  anterior  surface  with  the  deep 
fascia,  from  which  many  of  its  superior  fibres  arise, 
and  with  the  anterior  annular  ligament.  By  its 
posterior  surface  with  the  interosseous  membrane, 
tibia,  ankle  joint,  and  bones  of  the  tarsus  with  their  articulations.  By  its 
internal  surface  with  the  tibia.  By  the  external  surface  with  the  extensor 
longus  digitorum,  extensor  proprius  pollicis,  and  the  anterior  tibial  vessels 
and  nerve. 

The  EXTENSOR  LONGUS  DIGITORUM  arises  from  the  head  of  the  tibia, 
from  the  upper  three-fourths  of  the  fibula,  from  the  interosseous  mem- 
brane, and  from  the  deep  fascia.  Below,  it  divides  into  four  tendons, 
which  pass  beneath  the  annular  ligament,  to  be  inserted  into  the  second 
and  third  phalanges  of  the  four  lesser  toes.  The  mode  of  insertion  of  the 
extensor  tendons,  both  in  the  hand  and  in  the  foot,  is  remarkable :  each 
tendon  spreads  into  a  broad  aponeurosis  over  the  first  phalanx ;  this 
aponeurosis  divides  into  three  slips ;  the  middle  one  is  inserted  into  the 

*  The  muscles  of  the  anterior  tibial  region.  1.  The  extensor  muscles  inserted  into 
the  patella.  2.  The  subcutaneous  surface  of  the  tibia.  3.  The  tibialis  anticus.  4.  The 
extensor  longus  digitorum.  5.  The  extensor  proprius  pollicis.  6.  The  peroneus  tertius. 
7.  The  peroneus  longus.  8.  The  peroneus  brevis.  9,  9.  The  borders  of  the  soleus 
muscle.  10.  A  part  of  the  inner  belly  of  the  gastrocnemius.  11.  The  extensor  brevia 
digitorum ;  the  tendon  in  front  of  this  number  is  that  of  the  peroneus  tertius ;  ™,J  that 
behind  it.  the  tendon  of  the  peroneus  brevis. 

22      ' 


054  POSTERIOR   TIB1AL    REGION. 

base  of  the  second  phalanx,  and  the  two  lateral  slips  are  continued  on- 
wards,  to  be  inserted  into  the  base  of  the  third. 

Relations. — By  its  anterior  surface  with  the  deep  fascia  of  the  leg  and 
foot,  and  with  the  anterior  annular  ligament.  By  its  posterior  surface  with 
the  interosseous  membrane,  fibula,  ankle  joint,  extensor  brevis  digitorum 
which  separates  its  tendons  from  the  tarsus,  and  with  the  metatarsus  and 
phalanges.  By  its  inner  surface  with  the  tibialis  anticus,  extensor  pro- 
prius  pollicis,  and  anterior  tibial  vessels.  By  its  outer  border  with  the 
peroneus  longus  and  brevis. 

The  PERONEUS  TERTIUS  (flexor  tarsi  fibularis)  arises  from  the  lower 
fourth  of  the  fibula,  and  is  inserted  into  the  base  of  the  metatarsal  bone  of 
the  little  toe.  Although  apparently  but  a  mere  division  or  continuation 
of  the  extensor  longus  digitorum,  this  muscle  may  be  looked  upon  as 
analogous  to  the  flexor  carpi  ulnaris  of  the  fore-arm.  Sometimes  it  is  alto- 
gether wanting. 

The  EXTENSOR  PROPRIUS  POLLICIS  lies  between  the  tibialis  anticus  and 
extensor  longus  digitorum.  It  arises  from  the  lower  two-thirds  of  the 
fibula  and  interosseous  membrane.  Its  tendon  passes  through  a  distinct 
sheath  in  the  annular  ligament,  and  is  inserted  into  the  base  of  the  last 
phalanx  of  the  great  toe. 

Relations. — By  its  anterior  surface,  with  the  deep  fascia  of  the  leg  and 
foot,  and  with  the  anterior  annular  ligament.  By  its  posterior  surface, 
with  the  interosseous  membrane,  the  fibula,  the  tibia,  the  ankle  joint,  the 
extensor  brevis  digitorum,  and  the  bones  and  articulations  of  the  great  toe. 
It  is  crossed  upon  this  aspect  by  the  anterior  tibial  vessels  and  nerve.  By 
its  outer  side,  with  the  extensor  longus  digitorum,  and  in  the  foot  with  the 
dorsalis  pedis  artery  and  veins ;  the  outer  side  of  its  tendon  upon  the  dor- 
sum  of  the  foot  being  the  guide  to  those  vessels.  By  its  inner  side,  with 
the  tibialis  anticus,  and  with  the  anterior  tibial  vessels. 

Actions. — The  tibialis  anticus  and  peroneus  tertius  are  direct  flexors  of 
the  tarsus  upon  the  leg ;  acting  in  conjunction  with  the  tibialis  posticus, 
they  direct  the  foot  inwards,  and  with  the  peroneus  longus  and  brevis, 
outwards.  They  assist  also  in  preserving  the  flatness  of  the  foot  during 
progression.  The  extensor  longus  digitorum  and  extensor  proprius  pollicis, 
are  direct  extensors  of  the  phalanges ;  but,  continuing  their  action,  they 
assist  the  tibialis  anticus  and  peroneus  tertius  in  flexing  the  entire  foot 
upon  the  leg.  Taking  their  origin  from  below,  they  increase  the  stability 
of  the  ankle  joint. 

Posterior  Tibial  Region. 
Superficial  Group. 

Gastrocnemius, 

Plantaris, 

Soleus. 

Dissection. — Make  an  incision  from  the  middle  of  the  popliteal  space, 
down  tne  middle  of  the  posterior  part  of  the  leg  to  the  heel,  bounding  it 
mferiorly  by  a  transverse  incision,  passing  between  the  two  malleoli.  Turn 
aside  the  flaps  of  integument,  and  remove  the  fasciae  from  the  whole  of 
this  region  ;  the  gastrocnemius  muscle  will  then  be  exposed. 

The  GASTROCNEMIUS  (yaov^oxvViov,  the  bellied  part  of  the  leg)  arises, 
by  two  heads,  from  the  two  condyles  of  the  femur,  the  inner  head  being 


PLANTARIS — SOLEUS. 


255 


die  longest.     They  unite  to  form  the  beautiful  muscle  so         Fig.  133  * 

characteristic  of  this  region  of  the  limb.     It  is  inserted, 

by  means  of  the  tendo  Achillis,  into  the  lower  part  of 

the  posterior  tuberosity  of  the  os  calcis,  a  synovial  bursa 

jeing  placed  between  that  tendon  and  the  upper  part  of 

the  tuberosity.     The  gastrocnemius  must  be  removed 

from  its  origin,  and  turned  down,  in  order  to  expose  the 

next  muscle. 

Relations.  —  By  its  superficial  surface,  with  the  deep 
fascia  of  the  leg,  which  separates  it  from  the  external 
saphenous  vein,  and  with  the  external  saphenous  nerve. 
By  its  deep  surface,  with  the  lateral  portions  of  the  pos- 
terior ligament  of  the  knee  joint,  the  popliteus,  plantaris, 
and  soleus.  The  internal  head  of  the  muscle  rests 
against  the  posterior  surface  of  the  internal  condyle  of 
the  femur ;  the  external  head  against  the  outer  side  of 
the  external  condyle.  In  the  latter,  a  sesamoid  bone  is 
sometimes  found. 

The  PLANTARIS  (planta,  the  sole  of  the  foot),  an  ex- 
tremely diminutive  muscle,  situated  between  the  gastroc- 
nemius and  soleus,  arises  from  the  outer  condyle  of 
the  femur ;  and  is  inserted,  by  its  long  and  delicately 
slender  tendon,  into  the  inner  side  of  the  posterior 
tuberosity  of  the  os  calcis,  by  the  side  of  the  tendo 
Achillis :  having  crossed  obliquely  between  the  two 
muscles. 

The  SOLEUS  (solea,  a  sole),  is  the  broad  muscle  upon 
which  the  plantaris  rests.  It  arises,  from  the  head  and 
upper  third  of  the  fibula,  from  the  oblique  line  and  middle  third  of  the 
tibia.  Its  fibres  converge  to  the  tendo  Achillis,  by  which  it  is  inserted  into 
the  posterior  tuberosity  of  the  os  calcis.  Between  the  fibular  and  tibial 
origins  of  this  muscle  is  a  tendinous  arch,  beneath  which  the  popliteal 
vessels  and  nerve  pass  into  the  leg. 

Relations. — By  its  superficial  surface,  with  the  gastrocnemius  and  plan- 
taris. By  its  deep  surface,  with  the  intermuscular  fascia,  which  separates 
it  from  the  flexor  longus  digitorum,  tibialis  posticus,  flexor  longus  pollicis, 
from  the  posterior  tibial  vessels  and  nerve,  and  from  the  peroneal  vessels. 

Actions. — The  three  muscles  of  the  calf  draw  powerfully  on  the  os  cal- 
cis, and  lift  the  heel ;  continuing  their  action,  they  raise  the  entire  body. 
This  action  is  attained  by  means  of  a  lever  of  the  second  power,  the  ful- 
crum (the  toes)  being  at  one  end,  the  weight  (the  body  supported  on  the 
tibia)  in  the  middle,  and  the  power  (these  muscles)  at  the  other  extremity. 

They  are,  therefore,  the  walking  muscles,  and  perform  all  movements 
that  require  the  support  of  the  whole  body  from  the  ground,  as  dancing, 
leaping,  &c.  Taking  their  fixed  point  from  below,  they  steady  the  leg 
upon  the  foot. 

»  The  superficial  muscles  of  the  posterior  aspect  of  the  leg.  1.  The  biceps  muscle 
forming  the  outer  hamstring.  2.  The  tendons  forming  the  inner  hamstring.  3.  The 
popliteal  space.  4.  The  gastrocnemius  muscle.  5,  5.  The  soleus.  6.  The  tendo  Achillis 
7.  The  posterior  tuberosity  of  the  os  calcis.  8.  The  tendons  of  the  peroneus  longus  and 
hrevis  muscles  passing  behind  the  outer  ankle.  9.  The  tendons  of  the  tibialis  posticu* 
aud  flexor  longus  digitorum  passing  into  the  foot  behind  the  inner  ankle. 


250 


FLEXOR  LONGUS  DIGITORUM. 


Deep  Layer. 

Popliteus, 

Flexor  longus  pollicis, 
Flexor  longus  digitorum, 
Tibialis  posticus. 

Dissection. — After  the  removal  of  the  soleus,  the  deep  layer  will  be  found 
bound  down  by  an  intermuscular  fascia  which  is  to  be  dissected  away ; 
the  muscles  may  then  be  examined. 

The  POPLITEUS  muscle  (poples,  the  ham  of  the  leg)  forms  the  floor  of 
the  popliteal  region  at  its  lower  part,  and  is  bound  tightly  down  by  a  strong 
fascia  derived  from  th'e  middle  slip  of  the  tendon  of  the  semi-membranosus 
muscle.     It  arises  by  a  rounded  tendon  from  a  deep  groove  on  the  outer 
Fig.  134.*        side  °f  *ne  external  condyle  of  the  femur,  beneath  the  ex- 
ternal lateral  ligament ;  and  spreading  obliquely  over  the 
head  of  the  tibia,  is  inserted  into  the  surface  of  bone  above 
its  oblique  line.     This  line  is  called,  from  being  the  limit 
of  insertion  of  the  popliteal  muscle,  the  popliteal  line. 

Relations. — By  its  superficial  surface  with  a  thick  fascia 
which  separates  it  from  the  two  heads  of  the  gastrocne- 
mius,  the  plantaris,  and  the  popliteal  vessels  and  nerve- 
By  its  deep  surface  with  the  synovial  membrane  of  the  knee 
joint  and  with  the  upper  part  of  the  tibia. 

The  FLEXOR  LONGUS  POLLICIS  is  the  most  superficial 
of  the  next  three  muscles.  It  arises  from  the  lower  two- 
thirds  of  the  fibula,  and  passes  through  a  groove  in  the 
astragalus  and  os  calcis,  which  is  converted  by  tendinous 
fibres  into  a  distinct  sheath  lined  by  a  synovial  mem- 
brane, into  the  sole  of  the  foot ;  it  is  inserted  into  the  base 
of  the  last  phalanx  of  the  great  toe. 

Relations. — By  its  superficial  surface  with  the  intermus- 
cular fascia,  which  separates  it  from  the  soleus  and  tendo 
Achillis.  By  its  deep  surface  with  the  tibialis  posticus, 
fibula,  fibular  vessels,  interosseous  membrane,  and  ankle 
joint.  By  its  outer  border  with  the  peroneus  longus 
and  brevis.  By  its  inner  border  with  the  flexor  longus 
digitorum.  In  the  foot,  the  tendon  of  the  flexor  longus 
pollicis  is  connected  with  that  of  the  flexor  longus 
digitorum  by  a  short  tendinous  slip. 

The  FLEXOR  LONGUS  DIGITORUM  (perforans)  arises 
from  the  surface  of  the  tibia,  immediately  below  the  popliteal  line.  Its 
tendon  nasses  through  a  sheath  common  to  it  and  the  tibialis  posticus  be- 
hind the  inner  malleolus ;  it  then  passes  through  a  second  sheath  which  is 

*  The  deep  layer  of  muscles  of  the  posterior  tibial  region.  1.  The  lower  extremity 
of  the  femur.  2.  The  ligamentum  posticum  Winslowii.  3.  The  tendon  of  the  semi- 
membranosus  muscle  dividing  into  its  three  slips.  4.  The  internal  lateral  ligament  of 
.he  knee  joint.  5.  The  external  lateral  ligament.  6.  The  popliteus  muscle.  7.  The 
flexor  longus  digitorum.  8.  The  tibialis  posticus.  9.  The  flexor  longus  pollicis.  in. 
The  peroneus  longus  muscle.  1 1.  The  peroneus  brevis.  12.  The  tendo  Achillis  divided 
near  its  insertion  into  the  os  calcis.  13.  The  tendons  of  the  tibialis  posticus  and  flexor 
longus  digitorum  muscles,  just  as  they  are  about  to  pass  beneath  the  internal  annular 
ligament  of  the  ankle;  the  interval  between  the  latter  tendon  and  the  tendon  of  the 
flexor  longus  pollicis  is  occupied  by  the  posterior  tibial  vessels  and  nerve. 


FIBULAR    REGION.  257 

connected  with  a  groove  in  the  astragalus  and  os  calcis,  into  the  sole  of 
the  foot,  where  it  divides  into  four  tendons,  which  are  inserted  into  the 
base  of  the  last  phalanx  of  the  four  lesser  toes,  perforating  the  tendons  of 
the  flexor  brevis  digitorum. 

Relations. — By  its  superficial  surface  with  the  intermuscular  fascia, 
which  separates  it  from  the  soleus,  and  with  the  posterior  tibial  vessels  and 
nerve.  By  its  deep  surface  with  the  tibia  and  tibialis  posticus.  In  the  sole 
of  the  foot  its  tendon  is  in  relation  with  the  abductor  pollicis  and  flexor 
brevis  digitorum,  which  lie  superficially  to  it,  and  it  crosses  the  tendon  of 
the  flexor  longus  pollicis.  At  the  point  of  crossing  it  receives  the  tendi- 
nous slip  of  communication  from  the  latter. 

The  flexor  longus  pollicis  must  now  be  removed  from  its  origin,  and 
the  flexor  longus  digitorum  drawn  aside,  to  bring  into  view  the  entire  ex- 
tent of  the  tibialis  posticus. 

The  TIBIALIS  POSTICUS  (extensor  tarsi  tibialis)  lies  upon  the  interosseous 
membrane,  between  the  two  bones  of  the  leg.  It  arises  by  two  heads  from 
the  adjacent  sides  of  the  tibia  and  fibula  their  whole  length,  and  from  the 
interosseous  membrane.  Its  tendon  passes  inwards  beneath  the  tendon 
of  the  flexor  longus  digitorum,  and  runs  in  the  same  sheath ;  it  then  passes 
through  a  proper  sheath  over  the  deltoid  ligament,  and  beneath  the  calca- 
neo-scaphoid  articulation  to  be  inserted  into  the  tuberosity  of  the  scaphoid 
and  internal  cuneiform  bone.  While  in  the  common  sheath  behind  the 
internal  malleolus,  the  tendon  of  the  tibialis  posticus  lies  internally  to  that 
of  the  flexor  longus  digitorum,  from  which  it  is  separated  by  a  thin  fibrous 
partition.  A  sesamoid  bone  is  usually  met  with  in  the  tendon  close  to  its 
insertion. 

Relations. — By  its  superficial  surface  with  the  intermuscular  septum, 
the  flexor  longus  pollicis,  flexor  longus  digitorum,  posterior  tibial  vessels 
and  nerve,  peroneal  vessels,  and  in  the  sole  of  the  foot  with  the  abductor 
pollicis.  By  its  deep  surface  with  the  interosseous  membrane,  the  fibula 
and  tibia,  the  ankle  joint,  and  the  astragalus.  The  anterior  tibial  artery 
passes  between  the  two  heads  of  the  muscle. 

The  student  will  observe  that  the  two  latter  muscles  change  their  rela- 
tive position  to  each  other  in  their  course.  Thus,  in  the  leg,  the  position 
of  the  three  muscles  from  within  outwards,  is,  flexor  longus  digitorum, 
tibialis  posticus,  flexor  longus  pollicis.  At  the  inner  malleolus,  the  rela- 
tion of  the  tendons  is,  tibialis  posticus,  flexor  longus  digitorum,  both 
in  the  same  sheath ;  then  a  broad  groove,  which  lodges  the  posterior 
tibial  artery,  venae  comites,  and  nerve ;  and  lastly,  the  flexor  longus 
pollicis. 

Jictions. — The  popliteus  is  a  flexor  of  the  tibia  upon  the  thigh,  carrying 
it  at  the  same  time  inwards,  so  as  to  invert  the  leg.  The  flexor  longus 
pollicis  and  flexor  longus  digitorum  are  the  long  flexors  of  the  toes ;  their 
tendons  are  connected  in  the  foot  by  a  short  tendinous  band,  hence  they 
necessarily  act  together.  The  tibialis  posticus  is  an  extensor  of  the  tarsu« 
upon  the  leg,  and  an  antagonist  to  the  tibialis  anticus.  It  combines  with 
the  tibialis  anticus  in  adduction  of  the  foot. 

Fibular  Region. 


Peroneus  longus, 
Peroneus  brevis. 


22* 


258  FOOT DORSAL  REGION. 

Dissection.  —  These  muscles  are  exposed  by  continuing  the  dissection 
of  the  anterior  tibia!  region  outwards  beyond  the  fibula,  to  the  border  of 
the  posterior  tibial  region. 

The  PKRONEUS  LONGUS  (irs^dvY),  fibula,  extensor  tarsi  fibularis  longioi) 
muscle  arises  from  the  head  and  upper  third  of  the  outer  side  of  the  fibula, 
and  terminates  in  a  long  tendon,  which  passes  behind  the  external  mal- 
leolus,  and  obliquely  across  the  sole  of  the  foot,  through  the  groove  in  the 
cuboid  bone,  to  be  inserted  into  the  base  of  the  metatarsal  bone  of  the 
great  toe.  Its  tendon  is  thickened  where  it  glides  behind  the  external 
malleolus,  and  a  sesamoid  bone  is  developed  in  that  part  which  plays 
upon  the  cuboid  bone. 

Relations. — By  its  superficial  surface  with  the  fascia  of  the  leg  and  foot. 
By  its  deep  surface  with  the  fibula,  peroneus  brevis,  os  calcis,  and  cuboid 
bone,  and  near  the  head  of  the  fibula  with  the  fibular  nerve.  By  its  ante- 
rior border  it  is  separated  from  the  extensor  longus  digitorum  by  the 
attachment  of  the  fascia  of  the  leg  to  the  fibula ;  and  by  the  posterior 
border  by  the  same  medium  from  the  soleus  and  flexor  longus  pollicis. 
The  peroneus  longus  is  furnished  with  three  tendinous  sheaths  and  as 
many  synovial  membranes ;  the  first  is  situated  behind  the  external  mal- 
leolus, and  is  common  to  this  muscle  and  the  peroneous  brevis,  the  second 
on  the  outer  side  of  the  os  calcis,  and  the  third  on  the  cuboid  bone. 

The  PERONEUS  BREVIS  (extensor  tarsi  fibularis  brevior)  lies  beneath  the 
peroneus  longus ;  it  arises  from  the  lower  half  of  the  fibula,  and  terminates 
in  a  tendon  which  passes  behind  the  external  malleolus  and  through  a 
groove  in  the  os  calcis,  to  be  inserted  into  the  base  of  the  metatarsal  bone 
of  the  little  toe. 

Relations.  —  By  its  superficial  surface  with  the  peroneus  longus  and 
fascia  of  the  leg  and  foot.  By  its  deep  surface  with  the  fibula,  the  os 
calcis,  and  cuboid  bone.  The  lateral  relations  are  the  same  as  those  of 
the  peroneus  longus.  The  tendon  of  the  peroneus  brevis  has  but  two 
tendinous  sheaths  and  two  synovial  membranes,  one  behind  the  external 
malleolus  and  common  to  both  peronei,  the  other  upon  the  side  of  the  os 
calcis. 

Actions.  —  The  peronei  muscles  are  extensors  of  the  foot,  conjointly 
with  the  tibialis  posticus.  They  antagonize  the  tibialis  anticus  and  pero- 
neus tertius,  which  are  flexors  of  the  foot.  The  whole  of  these  muscles 
acting  together,  tend  to  maintain  the  flatness  of  the  foot,  so  necessary  to 
security  in  walking. 

FOOT. 

Dorsal  Region. 
Extensor  brevis  digitorum,  Interossei  dorsales. 

The  EXTENSOR  BREVJS  DIGITORUM  muscle  arises  from  the  outer  side  of 
the  os  calcis,  crosses  the  foot  obliquely,  and  terminates  in  four  tendons, 
the  innermost  of  which  is  inserted  into  the  base  of  the  first  phalanx  of  the 
great  toe,  and  the  other  three  into  the  sides  of  the  long  extensor  tendons 
of  the  second,  third,  and  fourth  toes. 

Rtlntions. — By  its  upper  surface  with  the  tendons  of  the  extensor  longus 
digitorum,  peroneus  brevis,  and  with  the  deep  fascia  of  the  foot.  By  its 
under  surface  with  the  tarsal  and  metatarsal  bones.  Its  inner  border  is  in 
relation  with  the  dorsalis  pedis  artery,  and  the  innermost  tendon  of  the 
muscle  crosses  that  artery  just  before  its  division. 


PLANTAR   REGION. 


259 


The  DORSAL  INTEROSSEI  muscles  are  placed  between  the  metatarsal 
oones ;  they  resemble  the  analogous  muscles  in  the  hand  in  arising  by 
two  heads  from  the  adjacent  sides  of  the  metatarsal  bones ;  their  tendons 
are  inserted  into  the  base  of  the  first  phalanx,  and  into  the  digital  expan- 
sion of  the  tendons  of  the  long  extensor. 

The  first  dorsal  interosseous  is  inserted  into  the  inner  side  of  the  second 
toe,  and  is  therefore  an  adductor ;  the  other  three  are  inserted  into  the 
outer  side  of  the  second,  third,  and  fourth  toes,  and  are  consequently 
abductors. 

Relations.  —  By  their  upper  surface  with  a  strong  fascia  which  separates 
them  from  the  extensor  tendons.  By  their  under  surface  with  the  plantar 
interossei.  Each  of  the  muscles  gives  passage  to  a  small  artery  (posterior 
perforating)  which  communicates  with  the  external  plantar  artery.  And 
between  the  heads  of  the  first  interosseous  muscle  the  communicating 
artery  of  the  dorsalis  pedis  takes  its  course. 


Fig.  135* 


Fig.  136.f 


Plantar  Region. 

First  Layer. 
Abductor  pollicis, 
Abductor  minimi  digiti, 
Flexor  brevis  digitorum. 

Dissection. — The  sole  of  the  foot  is  best  dissected  by  carrying  an  inci- 
sion around  the  heel,  and  along  the  inner  and  outer  borders  of  the  foot,  to 

*  Dorsal  interossei.     1.  Abductor  secundi.     2.  Adductor  secundi.     3.  Adductor  tertii. 

4.  Adductor  quarti. 

•j-  The  first  layer  of  muscles  in  the  sole  of  the  foot ;  this  layer  is  exposed  by  the  r»- 
moval  of  the  plantar  fascia.  1.  The  os  calcis.  2.  The  posterior  part  of  the  plantar 
fascia  divided  transversely.  3.  The  abductor  pollicis.  4.  The  abductor  minimi  digiti. 

5.  The  flexor  brevis  digitorum.     6.  The  tendon  of  the   flexor   longus  pollicis  muscle. 
7,  7.  The  lumbricales.     On  the  second  and  third  toes,  the  tendons  of  the  flexor  longn« 
digitorum  are  seen  passing  through  the  bifurcation  of  the  tendons  of  the  flexor  brevis 
digitorum. 


260 


MUSCLES  OF  THE  SOLE  OF  THE  FOOT. 


Fig.  137* 


the  great  and  little  toes.  This  incision  should  divide  the  integument  and 
superficial  fascia,  and  both  together  should  be  dissected  from  the  deep 
fascia,  as  far  forward  as  the  base  of  the  phalanges,  where  they  may  be  re- 
moved from  the  foot  altogether.  The  deep  fascia  should  then  be  removed, 
and  the  first  layer  of  muscles  will  be  brought  into  view. 

The  ABDUCTOR  POLLICIS  lies  along  the  inner  border  of  the  foot ;  it  arises 
by  two  heads,  between  which  the  tendons  of  the  long  flexors,  arteries, 
veins,  and  nerves  enter  the  sole  of  the  foot.  One  head  arises  from  the 
inner  tuberosity  of  the  os  calcis,  the  other  from  the  internal  annular  liga- 
ment and  plantar  fascia.  Insertion^  into  the  base  of  the  first  phalanx  of 
the  great  toe,  and  into  the  internal  sesamoid  bone. 

Relations.  —  By  its  superficial  surface  with  the  internal  portion  of  the 
plantar  fascia.  By  its  deep  surface  with  the  flexor  brevis  pollicis,  musculus 
accessorius,  tendons  of  the  flexor  longus  digitorum  and  flexor  longus  pol- 
licis, tendons  of  the  tibialis  anticus  and  posticus,  the  plantar  vessels  and 
nerves,  and  the  tarsal  bones.  On  its  outer  border  with  the  flexor  brevis 
digitorum,  from  which  it  is  separated  by  a  vertical  septum  of  the  plantar 
fascia. 

The  ABDUCTOR  MINIMI  DIGITI  lies  along  the  outei 
border  of  the  sole  of  the  foot.  It  arises  from  the  outer 
tuberosity  of  the  os  calcis,  and  from  the  plantar  fascia, 
as  far  forward  as  the  base  of  the  fifth  metatarsal  bone, 
and  is  inserted  into  the  base  of  the  first  phalanx  of  the 
little  toe. 

Relations.  —  By  its  superficial  surface  with  the  ex- 
ternal portion  of  the  plantar  fascia.  By  its  deep  sur- 
face with  the  musculus  accessorius,  flexor  brevis 
minimi  digiti,  with  the  tarsal  bones,  and  with  the 
metatarsal  bone  of  the  little  toe.  By  its  inner  side 
with  the  flexor  brevis  digitorum,  from  which  it  is  se- 
parated by  the  vertical  septum  of  the  plantar  fascia. 

The  FLEXOR  BREVIS  DIGITORUM  (perforatus)  is 
placed  between  the  two  preceding  muscles.  It  arises 
from  the  under  surface  of  the  os  calcis,  from  the 
plantar  fascia  and  intermuscular  septa,  and  is  inserted 
by  four  tendons  into  the  base  of  the  second  phalanx 
of  the  four  lesser  toes.  Each  tendon  divides,  pre- 
viously to  its  insertion,  to  give  passage  to  the  tendon 
of  the  long  flexor ;  hence  its  cognomen  perforatus. 
Relations.  —  By  its  superficial  surface  with  the  plantar  fascia.  By  its 
deep  surface  with  a  thin  layer  of  fascia  which  separates  it  from  the  muscu- 
lus accessorius,  tendons  of  the  flexor  longus  digitorum  and  flexor  longus 
pollicis,  and  plantar  vessels  and  nerves.  By  its  borders  with  the  vertical 
septa  of  the  plantar  fascia,  which  separate  the  muscle,  on  the  one  side 
from  the  abductor  pollicis,  and  on  the  other  from  the  abductor  minimi 
digiti. 

*  The  third  and  a  part  of  the  second  layer  of  muscles  of  the  sole  of  the  foot.  1.  The 
divided  edge  of  the  plantar  fascia.  2.  The  musculus  aocessorius.  3.  The  tendon  of  the 
flexor  longus  digitorurr  4.  The  tendon  of  the  flexor  longus  pollicis.  5.  The  flexor 
brevis  pollicis.  P.  The  adductor  pollicis.  7.  The  flexor  brevis  minimi  digiti.  8.  The 
transversus  pedis.  9.  Interossei  muscles,  plantar  and  dorsal.  10.  Convex  ridge  formed 
I>V  the  tendon  of  the  peroneus  longus  muscle  in  its  oblique  course  across  the  foot. 


MUSCLES  OF  THE  SOLE  OF  THE  FOOT. 


261 


Second  Layer. 


Musculus  accessorius, 


Lumbricales. 


Dissection.  —  The  three  preceding  muscles  must  be  divided  from  their 
origin,  and  anteriorly  through  their  tendons,  and  removed,  in  order  to 
bring  into  view  the  second  layer. 

The  MUSCULUS  ACCESSORIUS  arises  by  two  slips  from  either  side  of  the 
under  surface  of  the  os  calcis ;  the  inner  slip  being  fleshy,  the  outer,  ten- 
dinous. The  muscle  is  inserted  into  the  outer  side  and  upper  surface  of 
the  tendon  of  the  flexor  longus  digitorum. 

Relations.  —  By  its  superficial  surface,  with  the  three  muscles  of  the 
superficial  layer,  from  which  it  is  separated  by  their  fascial  sheaths,  and 
with  the  external  plantar  vessels  and  nerves.  By  its  deep  surface,  with 
the  under  surface  of  the  os  calcis  and  the  long  calcaneo-cuboid  ligament. 

The  LUMBRICALES  (lumbricus,  an  earthworm)  are  four  little  muscles, 
arising  from  the  tibial  side  of  the  tendons  of  the  flexor  longus  digitorum, 
and  inserted  into  the  expansion  of  the  extensor  tendons,  and  into  the  base 
of  the  first  phalanx  of  the  four  lesser  toes. 

Relations. — By  their  superficial  surface,  with  the          Fig.  138.* 
tendons  of  the  flexor  brevis  digitorum.     By  their  deep 
surface,  with  the  third  layer  of  muscles  of  the  sole  of 
the  foot.     They  pass  between  the  digital  slips  of  the 
deep  fascia  to  reach  their  insertion. 

Third  Layer. 

Flexor  brevis  pollicis, 
Adductor  pollicis, 
Flexor  brevis  minimi  digiti, 
Transversus  pedis. 

Dissection.  —  The  tendons  of  the  long  flexors,  and 
the  muscles  connected  with  them,  must  be  removed, 
to  see  clearly  the  attachments  of  the  third  layer. 

The  FLEXOR  BREVIS  POLLICIS  arises,  by  a  pointed 
tendinous  process,  from  the  side  of  the  cuboid,  and 
from  the  external  cuneiform  bone ;  it  is  inserted,  by 
two  heads,  into  the  base  of  the  first  phalanx  of  the 
great  toe.  Two  sesamoid  bones  are  developed  in  the 
tendons  of  insertion  of  these  two  heads,  and  the  tendon  of  the  flexor  longus 
pollicis  lies  in  the  groove  between  them. 

Relations. — By  its  superficial  surface,  with  the  abductor  pollicis,  tendon 
of  the  flexor  longus  pollicis,  and  plantar  fascia.  By  its  deep  surface,  with 
the  tarsal  bones  and  their  ligaments,  the  metatarsal  bone  of  the  great  toe, 
and  the  insertion  of  the  tendon  of  the  peroneus  longus.  By  its  inner  bor- 
der, with  the  abductor  pollicis ;  and  by  its  outer  border,  with  the  adductor 
pollicis  ;  with  both  of  these  muscles  it  is  blended  near  its  insertion. 

The  ADDUCTOR  POLLICIS  arises  from  the  cuboid  bone,  from  the  sheath 
of  the  tendon  of  the  peroneus  longus,  and  from  the  base  of  the  third  and 

*  Deep-seated  muscles  in  the  sole  of  the  foot.  1.  Tendon  of  the  flexor  longus  pollicw 
2.  Tendon  of  the  flexor  com  munis  digitorum  pedis.  3.  Flexor  accessorius.  4,  4.  Lum- 
bricales. 5.  Flexor  brevis  digitorum.  6.  Flexor  brevis  pollicis  pedis.  7.  Flexor  brev;s 
minimi  digiti  pedis. 


262          MUSCLES  OF  THE  SOLE  OF  THE  FOOT. 

fourtn  metatarsal  bones.  It  is  inserted  into  the  base  of  the  first  phalanx 
of  the  great  toe. 

Relations.  —  By  its  superficial  surface,  with  the  tendons  of  the  flexor 
longus  and  flexor  brevis  digitorum,  the  musculus  accessorius,  and  lumbri- 
cales.  By  its  deep  surface,  with  the  tarsal  bones  and  ligaments,  the  exter- 
nal plantar  artery  and  veins,  the  interossei  muscles,  tendon  of  the  peroneus 
longus,  and  metatarsal  bone  of  the  great  toe.  By  its  inner  border,  with  the 
flexor  brevis  pollicis ;  with  which  its  fibres  are  blended. 

The  FLEXOR  BREVIS  MINIMI  DIGITI  arises  from  the  base  of  the  metatar- 
sal bone  «f  the  little  toe,  and  from  the  sheath  of  the  tendon  of  the  peroneus 
longus.  It  is  inserted  into  the  base  of  the  first  phalanx  of  the  little  toe. 

Relations.  —  By  its  superficial  surface,  with  the  tendons  of  the  flexor 
longus  and  flexor  brevis  digitorum,  the  fourth  lumbricalis,  abductor 
minimi  digiti,  and  plantar  fascia.  By  its  deep  surface,  with  the  plantar 
interosseous  muscle  of  the  fourth  metatarsal  space,  and  the  metatarsal 
bone. 

The  TRANSVERSUS  PEDIS  arises,  by  fleshy  slips,  from  the  heads  of  the 
metatarsal  bones  of  the  four  lesser  toes.  Its  tendon  is  inserted  into  the 
base  of  the  first  phalanx  of  the  great  toe,  being  blended  with  that  of  the 
adductor  pollicis. 

Relations.  —  By  its  superficial  surface,  with  the  tendons  of  the  flexor 
longus  and  flexor  brevis  digitorum,  and  the  lumbricales.  By  its  deep 
surface,  with  the  interossei,  and  heads  of  the  metatarsal  bones. 

Fourth  Layer. 
Interossei  plantares. 

The  PLANTAR  INTEROSSEI  muscles  are  three  in  number,  and  are  placed 
upon,  rather  than  between,  the  metatarsal  bones.  They  arise  from  the 
base  of  the  metatarsal  bones  of  the  three  outer  toes,  and  are  inserted  into 
the  inner  side  of  the  extensor  tendon  and  base  of  the  first  phalanx  of  the 
same  toes. 

Relations.  —  By  their  superficial  surface,  with  the  dorsal  interossei  and 
the  metatarsal  bones.  By  their  deep  surface,  with  the  external  plantar 
artery  and  veins,  the  adductor  pollicis,  transversus  pedis,  and  flexor  mi- 
nimi digiti. 

Actions. — All  the  preceding  muscles  act  upon  the  toes  ;  and  the  move- 
ments which  they  are  capable  of  executing  may  be  referred  to  four  heads, 
viz.,  flexion,  extension,  adduction,  and  abduction.  In  these  actions  they 
are  grouped  in  the  following  manner : — 

Flexion.  Extension. 

Flexor  longus  digitorum,  Extensor  longus  digitorum, 

Flexor  brevis  digitorum,  Extensor  brevis  digitorum. 

Flexor  accessorius, 
Flexor  minimi  digiti. 

Adduction.  Abduction. 

Interossei       \  one  Dorsal,  Interossei,  three  dorsal, 

\  three  plantar.  Abductor  minimi  digiti. 


THE    FASCIAE. 


263 


The  great  toe,  like  the  thumb  in  the  hand,  enjoys  an 
independent  action,  and  is  provided  with  distinct  "mus- 
cles to  perform  its  movements.  These  movements  are 
precisely  the  same  as  those  of  the  other  toes,  viz. : 

Flexion. 

Flexor  longus  pollicis, 
Flexor  brevis  pollicis. 

Extension. 

Extensor  proprius  pollicis, 
Extensor  brevis  digitorum. 

Adduction. 
Adductor  pollicis. 

Abduction, 
Abductor  pollicis. 

The  only  muscles  excluded  from  this  table  are  the 
lumbricales,  four  small  muscles,  which,  from  their  at- 
tachments to  the  tendons  of  the  long  flexor,  appear  to 
be  assistants  to  its  action ;  and  the  transversus  pedis,  a  small  muscle 
placed  transversely  in  the  foot  across  the  heads  of  the  metatarsal  bones, 
which  has  for  its  office  the  drawing  together  of  the  toes. 


CHAPTER   V. 

ON  THE  FASCLE. 

FASCIA  (fascia,  a  bandage)  is  the  name  assigned  to  laminae  of  various 
extent  and  thickness,  which  are  distributed  through  the  different  regions 
of  the  body,  for  the  purpose  of  investing  or  protecting  the  softer  and  more 
delicate  organs.  From  a  consideration  of  their  structure,  these  fasciae  may 
be  arranged  into  two  groups :  cellulo-fibrous  fasciae,  and  aponeurotic 
fasciae. 

The  cellulo-fibrous  fascia  is  best  illustrated  in  the  common  subcutaneous 
investment  of  the  entire  body,  the  superficial  fascia.  This  structure  is  si- 
tuated immediately  beneath  the  integument  over  every  part  of  the  frame, 
and  is  the  medium  of  connexion  between  that  layer  and  the  deeper  parts. 
It  is  composed  of  cellulo-fibrous  tissue  containing  in  its  areolae  an  abun 
dance  of  adipose  cells.  The  fat  being  a  bad  conductor  of  caloric,  serves 
to  retain  the  warmth  of  the  body ;  while  it  forms  at  the  same  time  a  yield- 
ing tissue,  through  which  the  minute  vessels  and  nerves  pass  to  the  papil- 
lary layer  of  the  skin,  without  incurring  the  risk  of  obstruction  from  injury 
or  pressure  upon  the  surface.  By  dissection,  the  superficial  fascia  may  be 
separated  into  two  layers,  between  which  are  found  the  superficial  or  cu- 

*  Plantar  interossei.  ].  Abductor  tertii.  2.  Abductor  quarti.  3.  Interosseous  minimi 
dimti. 


0(J4  FASCIAE    OF    THE    HEAD    AND    ISECK. 

taneous  vessels  and  nerves ;  as  the  superficial  epigastric  artery,  the  sapne- 
nous  veins,  the  radial  and  ulnar  veins,  the  superficial  lymphatic  vessels, 
also  the  cutaneous  muscles,  as  the  platysma  myoides,  orbicularis  palpe- 
brarum,  sphincter  ani,  &c.  In  other  situations,  the  cellule-fibrous  fascia 
is  found  condensed  into  a  strong  and  inelastic  membrane,  as  is  exemplified 
in  the  deep  fascia  of  the  neck,  the  thoracic,  transversalis,  and  perineal 
fasciae,  and  the  sheaths  of  vessels. 

The  aponeurotic  fascia  is  the  strongest  kind  of  investing  membrane  ;  it 
is  composed  of  tendinous  fibres,  running  parallel  with  each  other,  and 
connected  by  other  fibres  of  the  same  kind  passing  in  different  directions. 
When  freshly  exposed,  it  is  brilliant  and  nacreous,  and  is  tough,  inelastic, 
and  unyielding.  In  the  limbs  it  forms  the  deep  fascia,  enclosing  and 
forming  distinct  sheaths  to  all  the  muscles  and  tendons.  It  is  thick  upon 
the  outer  and  least  protected  side  of  the  limb,  and  thinner  upon  its  inner 
side.  It  is  firmly  connected  to  the  bones,  and  to  the  prominent  points  of 
each  region,  as  to  the  pelvis,  knee,  and  ankle,  in  the  lower,  and  to  the 
clavicle,  scapula,  elbow,  and  wrist,  in  the  upper  extremity.  It  assists  the 
muscles  in  their  action,  by  keeping  up  a  tonic  pressure  on  their  surface  ; 
aids  materially  in  the  circulation  of  the  fluids  in  opposition  to  the  laws  of 
gravity ;  and  in  the  palm  of  the  hand  and  sole  of  the  foot  is  a  powerful 
protection  to  the  structures  which  enter  into  the  composition  of  these  re- 
gions. In  some  situations  its  tension  is  regulated  by  muscular  action,  as 
by  the  tensor  vaginae  femoris  and  gluteus  maximus  in  the  thigh,  by  the 
biceps  in  the  leg,  and  by  the  biceps  and  palmaris  longus  in  the  arm  ;  in 
other  situations  it  affords  an  extensive  surface  for  the  origin  of  the  fibres 
of  muscles. 

The  fasciae  may  be  arranged  like  the  other  textures  of  the  body  into,  1. 
Those  of  the  head  and  neck.  2.  Those  of  the  trunk.  3.  Those  of  the 
upper  extremity.  4.  Those  of  the  lower  extremity. 

FASCIAE     OF     THE     HEAD     AND     NECK. 

The  TEMPORAL  FASCIA  is  a  strong  aponeurotic  membrane  which  covers 
in  the  temporal  muscle  at  each  side  of  the  head,  and  gives  origin  by  its 
internal  surface  to  some  of  its  muscular  fibres.  It  is  attached  to  the  whole 
extent  of  the  temporal  ridge  above,  arid  to  the  zygomatic  arch  below  ;  in 
the  latter  situation  it  is  thick  and  divided  into  two  layers,  the  external 
being  connected  to  the  upper  border  of  the  arch,  and  the  internal  to  its 
inner  surface.  A  small  quantity  of  fat  is  usually  found  between  these  two 
layers,  together  with  the  orbital  branch  of  the  temporal  artery. 

CERVICAL  FASCIA. — The  fasciaa  of  the  neck  are  the  superficial  and  the 
deep.  The  superficial  cervical  fascia  is  a  part  of  the  common  superficial 
fascia  of  the  entire  body,  and  is  only  interesting  from  containing  between 
its  layers  the  platysma  myoides  muscle. 

The  deep  cervical  fascia  is  a  strong  cellule-fibrous  layer  which  invests 
the  muscles  of  the  neck,  and  retains  and  supports  the  vessels  and  nerves. 
It  commences  posteriorly  at  the  ligamentum  nuchas,  and  passes  forwards 
at  each  side  beneath  the  trapezius  muscle  to  the  posterior  border  of  the 
sterno-mastoid  ;  here  it  divides  into  two  layers,  which  embrace  that  muscle 
and  unite  upon  its  anterior  border  to  be  prolonged  onwards  to  the  middle 
line  of  the  neck,  where  it  becomes  continuous  with  the  fascia  of  the  oppo- 
Mte  side.  Besides  feus  constituting  a  sheath  for  the  sterno-mastoid,  it 


FASCIAE   OF   THE    TRUiN'K. 


265 


Fig.  140» 


also  forms  sheaths  for  the  other  muscles  of  the  neck  over  which  it  passes 
If  the  superficial  layer  of  the  sheath  of  the  sterno-mastoid  be  traced  up- 
wards,  it  will  be  found  to  pass  over  the  parotid  gland  and  masseter  muscle, 
and  to  be  inserted  into  the  zygomatic 
arch  ;  and  if  it  be  traced  downwards,  it 
will  be  seen  to  pass  in  front  of  the  clavi- 
cle, and  become  lost  upon  the  pectoralis 
major  muscle.  If  the  deep  layer  of  the 
sheath  be  examined  superiorly,  it  will  be 
found  attached  to  the  styloid  process, 
from  which  it  is  reflected  to  the  angle  of 
the  lower  jaw,  forming  the  stylo-maxil- 
lary ligament ;  and  if  it  be  followed 
downwards,  it  will  be  found  connected 
with  the  tendon  of  the  omo-hyoid  mus- 
cle, and  may  thence  be  traced  behind 
the  clavicle,  where  it  encloses  the  sub- 
clavius  muscle,  and,  being  extended 
from  the  cartilage  of  the  first  rib  to  the 
coracoid  process,  constitutes  the  costo- 
coracoid  membrane.  In  front  cf  the  sterno-mastoid  muscle,  the  deep 
fascia  is  attached  to  the  border  of  the  lower  jaw  and  os  hyoides,  and  forms 
a  distinct  sheath  for  the  submaxillary  gland.  Inferiorly  it  divides  into  two 
layers,  one  of  which  passes  in  front  of  the  sternum,  while  the  other  is  at- 
tached to  its  superior  border. 

FASCIJE    OF    THE    TRUNK. 

The  thoracic  fascia\  is  a  dense  layer  of  cellulo-fibrous  membrane, 
stretched  horizontally  across  the  superior  opening  of  the  thorax.  It  is 
firmly  attached  to  the  concave  margin  of  the  first  rib,  and  to  the  inner 
surface  of  the  sternum.  In  front  it  leaves  an  opening  for  the  connexion 
of  the  cervical  with  the  thoracic  portion  of  the  thymus  gland,  and  behind 
it  forms  an  arch  across  the  vertebral  column,  to  give  passage  to  the 
oesophagus. 

At  the  point  where  the  great  vessels  and  trachea  pass  through  the  tho- 
racic fascia,  it  divides  into  an  ascending  and  descending  layer.  The 

*  A  transverse  section  of  the  neck,  showing  the  deep  cervical  fascia  and  its  numerous 
prolongations,  forming  sheaths  for  the  different  muscles.  As  the  figure  is  symmetrical, 
the  figures  of  reference  are  placed  only  on  one  side.  1.  The  platysma  myoides.  2. 
The  trapezius.  3.  The  ligamentum  nuchae,  from  which  the  fascia  may  be  traced  br- 
wards  beneath  the  trapezi.ss,  enclosing  the  other  muscles  of  the  neck.  4.  The  point  at 
which  the  fascia  divides,  to  form  a  sheath  for  the  sterno-mastoid  muscle  (5).  6.  The 
point  of  reunion  of  the  two  layers  of  the  sterno-mastoid  sheath.  7.  The  point  of  union 
of  the  deep  cervical  fascia  of  opposite  sides  of  the  neck.  8.  Section  of  the  sterno-hyoid. 
9.  Omo-hyoid.  10.  Sterno-thyroid.  11.  The  lateral  lobe  of  the  thyroid  gland.  12.  The 
trachea.  13.  The  ossophagus.  14.  The  sheath  containing  the  common  carotid  artery, 
internal  jugular  vein,  and  pneumogastric  nerve.  15.  The  longus  colli.  The  nerve  in 
front  of  the  sheath  of  this  muscle  is  the  sympathetic.  16.  The  rectus  anticus  major. 
17.  Scalenus  anticus.  18.  Scalenus  postk-us.  19.  The  splenius  capitis.  20.  Splenius 
colli.  21.  Levator  anguli  scapulae.  22.  Complexus.  23.  Trachelo-mastoid.  24.  Trans- 
versalis  colli.  25.  Cervicalis  ascendens.  26.  The  semi-spinalis  colli.  27.  The  multi- 
fidus  spinae.  28.  A  cervical  vertebra.  The  transverse  processes  are  seen  to  be  traversed 
by  the  vertebral  artery  and  vein. 

f  For  an  excellent  description  of  this  fascia,  see  Sir  Astley  Cooper's  work  'n  i'  « 
"Anatomy  of  the  Thymus  Gland." 

23 


266  ABDOMINAL    FASCLE. 

ascending  layer  is  attached  to  the  trachea,  and  becomes  continuous  with 
the  sheath  of  the  carotid  vessels,  and  with  the  deep  cervical  fascia ;  the 
descending  layer  descends  upon  the  trachea  to  its  bifurcation,  surrounds 
the  large  vessels  arising  from  the  arch  of  the  aorta,  and  the  upper  part  of 
the  arch  itself,  and  is  continuous  with  the  fibrous  layer  of  the  pericardium. 
It  is  connected  also  with  the  venae  innominatse  and  superior  cava,  and  is 
attached  to  the  cellular  capsule  of  the  thymus  gland. 

"  The  thoracic  fascia,"  whites  Sir  Astley  Cooper,  "  performs  three  im- 
portant offices : — 

"  1st.  It  forms  the  upper  boundary  of  the  chest,  as  the  diaphragm  does 
the  lower. 

"  2d.  It  steadily  preserves  the  relative  situation  of  the  parts  which  enter 
and  quit  the  thoracic  opening. 

"  3d.  It  attaches  and  supports  the  heart  in  its  situation,  through  the 
medium  of  its  connexion  with  the  aorta  and  large  vessels  which  are  placed 
at  its  curvature." 

ABDOMINAL    FASCIA. 

The  lower  part  of  the  parietes  of  the  abdomen,  and  the  cavity  of  the 
pelvis,  are  strengthened  by  a  layer  of  fascia  which  lines  their  internal  sur- 
face, and  at  the  bottom  of  the  latter  cavity  is  reflected  inwards  to  the  sides 
of  the  bladder.  This  fascia  is  continuous  throughout  the  whole  of  the 
above-mentioned  surface ;  but  for  convenience  of  description  is  considered 
under  the  several  names  of  transversalis  fascia,  iliac  fascia,  and  pelvic 
fascia ;  the  two  former  meet  at  the  crest  of  the  ilium  and  Poupart's  liga- 
ment, and  the  latter  is  confined  to  the  cavity  of  the  true  pelvis. 

The  fascia  transversaliK  (Fascia  Cooperi)*  is  a  cellulo-fibrous  lamella, 
which  lines  the  inner  surface  of  the  transversalis  muscle.  It  is  thick  and 
dense  below,  near  the  lower  part  of  the  abdomen  ;  but  becomes  thinner 
as  it  ascends,  and  is  gradually  lost  in  the  subserous  cellular  tissue.  It  is 
attached  inferiorly  to  the  reflected  margin  of  Poupart's  ligament  and  to  the 
crest  of  the  ilium;  internally,  to  the  border  of  the  rectus  muscle ;  and,  at 
the  inner  third  of  the  femoral  arch,  is  continued  beneath  Poupart's  liga- 
ment, and  forms  the  anterior  segment  of  the  crural  canal,  or  sheath  of 
the  femoral  vessels. 

The  internal  abdominal  ring  is  situated  in  this  fascia-,  at  about  midway 
between  the  spine  of  the  os  pubis  and  the  anterior  superior  spine  of  the 
ilium,  and  half  an  inch  above  Poupart's  ligament ;  it  is  bounded  upon  its 
inner  side  by  a  well-marked  falciform  border,  but  is  ill  defined  around  its 
outer  margin.  From  the  circumference  of  this  ring  is  given  off  an  infundi- 
buliform  process,  which  surrounds  the  testicle  and  spermatic  cord,  consti- 
tuting the  fascia  propria  of  the  latter,  and  forms  the  first  investment  to  the 
sac  of  oblique  inguinal  hernia.  It  is  the  strength  of  this  fascia,  in  the  in- 
terval between  the  tendon  of  the  rectus  and  the  internal  abdominal  ring, 
that  defends  this  portion  of  the  parietes  from  the  frequent  occurrence  of 
direct  inguinal  hernia. 

INGUINAL     HERNIA. 

Inguinal  hernia  is  of  two  kinds,  oblique  and  direct. 

In  OBLIQUE  INGUINAL  HERNIA  the  intestine  escapes  from  the  cavity  of 

'  Sir  Ai.iey  Cooper  first  described  this  fascia  in  its  important  relation  to  inguinal 
hernia 


INGUINAL    HERNIA.  267 

Jie  abdomen  into  the  spermatic  canal,  through  the  internal  abdominal  nng, 
pressing  before  it  a  pouch  of  peritoneum  which  constitutes  the  hernial  sac, 
and  distending  the  infundibuliform  process  of  the  transversalis  fascia. 
After  emerging  through  the  internal  abdominal  ring,  it  passes  first  beneath 
the  lower  and  arched  border  of  the  transversalis  muscle ;  t/ien  beneath  the 
lower  border  of  the  internal  oblique  muscle;  and  finally  through  the  ex- 
ternal abdominal  ring  in  the  aponeurosis  of  the  external  oblique.  From 
the  transversalis  muscle  it  receives  no  investment ;  while  passing  beneath 
the  lower  border  of  the  internal  oblique  it  obtains  the  cremaster  muscle ; 
and,  upon  escaping  at  the  external  abdominal  ring,  receives  the  inter- 
colurnnar  fascia.  So  that  the  coverings  of  an  oblique  inguinal  hernia, 
after  it  has  emerged  through  the  external  abdominal  ring,  are,  from  the 
surface  to  the  intestine,  the 

Integument,  Cremaster  muscle, 

Superficial  fascia,  Transversalis,  or  infundibuliform  fascia, 

Intercolumnar  fascia,  Peritoneal  sac. 

The  spermatic  canal,  which,  in  the  normal  condition  of  the  abdominal 
parietes  serves  for  the  passage  of  the  spermatic  cord  in  the  male,  and  the 
round  ligament  with  its  vessels  in  the  female,  is  about  one  inch  and  a 
half  in  length.  It  is  bounded  in  front  by  the  aponeurosis  of  the  external 
oblique  muscle  '^behind  by  the  transversalis  fascia,  and  the  conjoined  ten- 
don of  the  internal  oblique  and  transversalis  muscle ;  above  by  the  arched 
borders  of  the  internal  oblique  and  transversalis ;  below  by  the  grooved 
oorder  of  Pou part's  ligament,  and  at  each  extremity  by  one  of  the  abdo- 
minal rings,  the  internal  ring  at  the  inner  termination,  the  external  ring  at 
the  outer  extremity.  These  relations  may  be  more  distinctly  illustrated 
by  the  following  plan — 

Move. 

Lower  borders  of  internal  oblique 
and  transversalis  muscle. 

In  Front.  Behind. 

Transversalis    fascia. 


Aponeurosis  of  exter- 


Spermatic  canal. 


nal  oblique. 

internal  oblique  and 


Conjoined  tendon  of 


transversalis. 
Below. 

Grooved  border  of 
Poupart's  ligament. 

There  are  three  varieties  of  oblique  inguinal  hernia : — common,  congen- 
ital, and  encysted. 

Common  oblique  hernia  is  that  which  has  been  described  above. 

Congenital  hernia  results  from  the  nonclosure  of  the  pouch  of  peritoneum 
carried  downwards  into  the  scrotum  by  the  testicle,  during  its  descent  in 
the  fetus. 

The  intestine  at  some  period  of  life  is  forced  into  this  canal,  and  de- 
scends through  it  into  the  tunica  vaginalis  where  it  lies  in  contact  with  the 
testicle ;  so  that  congenital  hernia  has  no  proper  sac,  but  is  contained 
within  the  tunica  vaginalis.  The  other  coverings  are  the  same  as  thoso 
of  common  inguinal  hernia. 

Encysted  hernia  (hernia  infantilis,  of  Hey)  is  that  form  of  protrusion  iu 
which  the  pouch  of  peritoneum  forming  the  tunica  vaginalis,  being  only 
partially  closed,  and  remaining  open  externally  to  the  abdomen,  admits 


268  FASCIA    ILIACA — FASCIA    PELVICA. 

of  the  hernia  passing  into  the  scrotum,  behind  the  tunica  vaginalis.  So 
that  the  surgeon  in  operating  upon  this  variety,  requires  to  divide  three 
layers  of  serous  membrane  ;  the  first  and  second  layers  being  those  of  the 
tunica  vaginalis  ;  and  the  third  the  true  sac  of  the  hernia. 

DIRECT  INGUINAL  HERNIA  has  received  its  name  from  passing  directly 
through  the  external  abdominal  ring,  and  forcing  before  it  the  opposing 
parietes.  This  portion  of  the  wall  of  the  abdomen  is  strengthened  by  the 
conjoined  tendon  of  the  internal  oblique  and  transversalis  muscle,  which 
is  pressed  before  the  hernia,  and  forms  one  of  its  investments.  Its>  cover 
ings  are,  the 

Integument,  Conjoined  tendon, 

Superficial  fascia,  Transversalis  fascia, 

Intercolumnar  fascia,  Peritoneal  sac. 

Direct  inguinal  hernia  differs  from  oblique  in  never  attaining  the  same 
bulk,  in  consequence  of  the  resisting  nature  of  the  conjoined  tendon  of  the 
internal  oblique  and  transversalis  and  of  the  transversalis  fascia;  in  its  di- 
rection, having  a  tendency  to  protrude  from  the  middle  line  rather  than 
towards  it.  Thirdly,  in  making  for  itself  a  new  passage  through  the  ab- 
dominal parietes,  instead  of  following  a  natural  channel ;  and  fourthly,  in 
the  relation  of  the  neck  of  its  sac  to  the  epigastric  artery ;  that  vessel  lying 
to  the  outer  side  of  the  opening  of  the  sac  of  direct  hernia,  and  to  the 
inner  side  of  that  of  oblique  hernia. 

All  the  forms  of  inguinal  hernia  are  designated  scrotal,  when  they  have 
descended  into  that  cavity. 

The  FASCIA  ILIACA  is  the  aponeurotic  investment  of  the  psoas  and  iliacus 
muscles ;  and,  like  the  fascia  transversalis,  is  thick  below,  and  becomes 
gradually  thinner  as  it  ascends.  It  is  attached  superiorly  along  the  edge 
of  the  psoas,  to  the  anterior  lamella  of  the  aponeurosis  of  the  transversalis 
muscle,  to  the  ligamentum  arcuatum  internum,  and  to  the  bodies  of  the 
lumbar  vertebra,  leaving  arches  corresponding  with  the  constricted  portions 
of  the  vertebra  for  the  passage  of  the  lumbar  vessels.  Lower  down  it 
passes  beneath  the  external  iliac  vessels,  and  is  attached  along  the  margin 
of  the  true  pelvis ;  externally,  it  is  connected  to  the  crest  of  the  ilium ; 
and,  inferiority,  to  the  outer  two-thirds  of  Poupart's  ligament,  where  it  is 
continuous  with  the  fascia  transversalis.  Passing  beneath  Poupart's  liga- 
ment, it  surrounds  the  psoas  and  iliacus  muscles  to  their  termination,  and 
beneath  the  inner  third  of  the  femoral  arch  forms  the  posterior  segment  of 
the  sheath  of  the  femoral  vessels. 

The  FASCIA  PELVICA  is  attached  to  the  inner  surface  of  the  os  pubis, 
and  along  the  margin  of  the  brim  of  the  pelvis,  where  it  is  continuous 
with  the  iliac  fascia.  From  this  extensive  origin  it  descends  into  the  pel- 
vis, and  divides  into  two  layers,  the  pelvic  and  obturator. 

The  pelvic  layer  or  fascia,  when  traced  from  the  internal  surface  of  the 
os  pubis  near  the  symphysis,  is  seen  to  be  reflected  inwards  to  the  neck 
of  the  bladder,  so  as  to  form  the  anterior  vesical  ligaments.  Traced 
backwards,  it  passes  between  the  sacral  plexus  of  nerves  and  the  internal 
iliac  vessels,  and  is  attached  to  the  anterior  surface  of  the  sacrum ;  and 
followed  from  the  sides  of  the  pelvis,  it  descends  to  the  base  of  the  bladder 
and  divides  into  three  layers,  one,  ascending,  is  reflected  upon  the  side  of 
that  viscus,  encloses  the  vesical  plexus  of  veins,  and  forms  the  lateral  liga- 
ments of  the  bladder.  A  middle  layer  passes  inwards  between  the  base 


PERINEAL    FASCIAE.  269 

of  the  bladder  and  the  upper  surface  of  the  rectum,  and  was  named  by 
Mr.  Tyrrell  the  redo-vesical  fascia ;  and  an  inferior  layer  passes  behind 
the  rectum,  and,  with  the  layer  of  the  opposite  side,  completely  invests 
that  intestine 


Fig.  141.* 


The  obturator  fascia  passes  directly  downwards  from  the  splitting  of 
the  layers  of  the  pelvic  fascia,  and  covers  in  the  obturator  internus  muscle 
and  the  internal  pudic  vessels  and  nerve  ;  it  is  attached  to  the  ramus  of 
the  os  pubis  and  ischium  in  front,  and  below  to  the  falciform  margin  of 
the  great  sacro-ischiatic  ligament.  Lying  between  these  two  layers  of 
fascia  is  the  levator  ani  muscle,  which  arises  from  their  angle  of  separa 
tion.  The  levator  ani  is  covered  in  inferiorly  by  a  third  layer  of  fascia, 
which  is  given  off  by  the  obturator  fascia,  and  is  continued  downwards 
upon  the  inferior  surface  of  the  muscle  to  the  extremity  of  the  rectum, 
where  it  is  lost.  This  layer  may  be  named,  from  its  position  and  inferior 
attachment,  the  anal  fascia. 

PERINEAL  FASCIA. — In  the  perineum  there  are  two  fasciae  of  much  im- 
portance, the  superficial  and  deep  perineal  fascia. 

The  superficial  perineal  fascia  is  a  thin  aponeurotic  layer,  which  covers 
in  the  muscles  of  the  genital  portion  of  the  perineum  and  the  root  of  the 
penis.  It  is  firmly  attached  at  each  side  to  the  ramus  of  the  os  pubis  and 
ischium ;  posteriorly  it  is  reflected  backwards  beneath  the  transversi  perinei 
muscles,  to  become  connected  with  the  deep  perineal  fascia ;  while  ante- 
riorly it  is  continuous  with  the  dartos  of  the  scrotum. 

The  deep  perineal  fascia  (Camper's  ligament,  triangular  ligament)  is 
situated  behind  the  root  of  the  penis,  and  is  firmly  stretched  across  be- 
tween the  ramus  of  the  os  pubis  and  ischium  of  each  side,  so  as  to  con- 
stitute a  strong  septum  of  defence  to  the  outlet  of  the  pelvis.  At  its  infe- 

*  A  transverse  section  of  the  pelvis,  showing  the  distribution  of  the  pelvic  fascia. 
1.  The  bladder.  2.  The  vesicula  seminalis  of  one  side,  divided  across.  3.  The  rectum. 
4.  The  iliac  fascia,  covering  in  the  iliacus  and  psoas  muscles  (5)  ;  and  forming  a  sheath 
for  the  external  iliac  vessels  (G).  7.  The  anterior  crural  nerve,  excluded  from  tho 
sheath.  8.  The  pelvic  fascia,  9.  Its  ascending  layer,  forming  the  lateral  ligament  of 
the  bladder  of  one  side,  and  a  sheath  to  the  vesical  plexus  of  veins.  10.  The  recto 
vesical  fascia  of  Mr.  Tyrrell,  formed  by  the  middle  layer.  11.  The  inferior  layer  sur- 
rounding the  rectum  and  meeting  at  the  middle  line  with  the  fascia  of  the  opposite  side. 
12.  The  levator  ani  muscle.  13.  The  obturator  internns  muscle,  covered  in  by  the  ob 
turator  fascia,  which  also  forms  a  sheath  for  the  internal  pudic  vessels  and  nerve  (14). 
15.  The  layer  of  fascia  which  invests  the  under  surface  of  the  levator  ani  muscle,  ill" 
anal  fascia. 

23* 


270 


PERINEAL    FASCIAE. 


rior  border  it  divides  into  two  layers,  one  of  which  is  continued  forwards, 
and  is  continuous  with  the  superficial  perineal  fascia ;  while  the  other  is 


Fig.  142.* 


Fig.  143.f 


prolonged  backwards  to  the  rectum,  and,  joining  with  the  anal  fascia, 
assists  in  supporting  the  extremity  of  that  intestine.  The  deep  perineal 
fascia  is  composed  of  two  layers,  which  are  separated  from  each  other  by 
several  important  parts,  and  traversed  by  the  membranous  portion  of  the 
urethra.  The  anterior  layer  is  nearly  plane  in  its  direction,  and  sends  a 
sheath  forwards  around  the  anterior  termination  of  the  membranous  ure- 
thra, to  be  attached  to  the  posterior  part  of  the  bulb.  The  posterior  layer 
is  oblique,  and  sends  a  funnel-shaped  process  backwards,  which  invests 

the  commencement  of  the  mem- 
branous urethra  and  the  prostate 
gland.  The  inferior  segment  of 
this  funnel-shaped  process  is 
continued  backward  beneath  the 
prostate  gland  and  the  vesiculae 
seminales,  and  is  continuous  with 
the  recto-vesical  fasciae  of  Tyr- 
rell, which  is  attached  poste- 
riorly to  the  recto-vesical  fold 
of  peritoneum,  and  serves  the 
important  office  of  retaining  that 
duplicature  in  its  proper  situa- 
tion. 

•The  pubic  arch  with  the  attachments  of  the  perineal  fasciae.  1,  1,  1.  The  superfl 
eial  perineal  fascia  divided  by  a  ^  shaped  incision  into  three  flaps  ;  the  lateral  flaps 
are  turned  over  the  ramus  of  the  os  pubis  and  ischium  at  each  side,  to  which  they  are 
firmly  attached ;  tue  posterior  flap  is  continuous  with  the  deep  perineal  fascia.  2.  The 
deep  perineal  fascia.  3.  The  opening  for  the  passage  of  the  membranous  portion  of  the 
•urethra,  previously  to  entering  the  bulb.  4.  Two  projections  of  the  anterior  layer  of  the 
deep  perineal  faspcia,  corresponding  with  the  position  of  Cowpers  glands. 

t  A  side  view  of  the  viscera  of  the  pelvis,  showing  the  distribution  of  the  perineal 
nnd  pelvic  fasciae.  1.  The  symphysis  pubis.  2.  The  bladder.  3.  The  recto-vesical  fold 
of  peritoneum,  passing  from  the  anterior  surface  of  the  rectum  to  the  posterior  part  of 
»i.«  bladder ;  from  the  upper  part  of  the  fundus  of  the  bladder  i.  is  reflected  upon  the 


FASCLE    OF    THE    UPPER    EXTREMITY.  271 

Between  the  two  layers  of  the  deep  perineal  fascia  are  situated,  there- 
fore, the  whole  extent  of  the  membranoifs  portion  of  the  urethra,  the  com- 
pressor urethras  muscle,  Cowper's  glands,  the  internal  pudic  and  bulbous 
arteries,  and  a  plexus  of  veins.  Mr.  Tyrrell  considers  the  anterior  lamella 
alone  as  the  deep  perineal  fascia,  and  the  posterior  lamella  as  a  distinct 
layer  of  fascia,  covering  in  a  considerable  plexus  of  veins. 

FASCIA    OF    THE    UPPER    EXTREMITY. 

The  superficial  fascia  of  the  upper  extremity  contains  between  its  layers 
the  superficial  veins  and  lymphatics,  and  the  superficial  nerves. 

The  deep  fascia  is  thin  over  the  deltoid  and  pectoralis  major  muscles, 
and  in  the  axillary  space,  but  thick  upon  the  dorsum  of  the  scapula,  where 
it  binds  down  the  infra-spinatus  muscle.  It  is  attached  to  the  clavicle, 
acromion  process,  and  spine  of  the  scapula.  In  the  upper  arm  it  is  some- 
what stronger,  and  is  inserted  into  the  condyloid  ridges,  forming  the  in- 
termuscular  septa.  In  the  fore-arm  it  is  very  strong,  and  at  the  bend  of 
the  elbow  its  thickness  is  augmented  by  a  broad  band,  which  is  given  off 
from  the  inner  side  of  the  tendon  of  the  biceps.  It  is  firmly  attached  to 
the  olecranon  process,  to  the  ulna,  and  to  the  prominent  points  about  the 
wrist.  Upon  the  front  of  the  wrist  it  is  continuous  with  the  anterior  annu- 
lar ligament,  which  is  considered  by  some  anatomists  to  be  formed  by  the 
deep  fascia,  but  which  I  am  more  disposed  to  regard  as  a  ligament  of  the 
wrist.  On  the  posterior  aspect  of  this  joint,  it  forms  a  strong  transverse 
band,  the  posterior  annular  ligament,  beneath  which  the  tendons  of  the 
extensor  muscles  pass,  in  distinct  sheaths.  The  attachments  of  the  pos- 
terior annular  ligament  are,  the  radius  on  one  side,  and  the  ulna  and  pisi- 
form bone  on  the  opposite  side  of  the  joint. 

The  tendons,  as  they  pass  beneath  the  annular  ligaments,  are  surrounded 
by  synovial  bursse.  The  dorsum  of  the  hand  is  invested  by  a  thin  fascia, 
which  is  continuous  with  the  posterior  annular  ligament. 

The  palmar  fascia  is  divided  into  three  portions.  A  central  portion, 
which  occupies  the  middle  of  the  palm,  and  two  lateral  portions,  which 
spread  out  over  the  sides  of  the  hand,  and  are  continuous  with  the  dorsal 
fascia.  The  central  portion  is  strong  and  tendinous :  it  is  narrow  at  the 
wrist,  where  it  is  attached  to  the  annular  ligament,  and  broad  over  the 
heads  of  the  metacarpal  bones,  where  it  divides  into  eight  slips,  which  are 
inserted  into  the  sides  of  the  base  of  the  first  phalanx  of  each  finger.  The 

abdominal  parietes.  4.  The  ureter.  5.  The  vas  deferens  crossing  the  direction  of  the 
ureter.  6.  The  vesicula  seminalis  of  the  right  side.  7,  7.  The  prostate  gland  divided 
by  a  longitudinal  section.  8,  8.  The  section  of  a  ring  of  elastic  tissue  encircling  the 
prostatic  portion  of  the  urethra  at  its  commencement.  9.  The  prostatic  portion  of  the 
urethra.  10.  The  membranous  portion,  enclosed  by  the  compressor  uretbroe  muscle. 
11.  The  commencement  of  the  corpus  spongiosum  penis,  the  bulb.  12.  The  anterior 
ligaments  of  the  bladder,  formed  by  the  reflection  of  the  pelvic  fascia,  from  the  internal 
surface  of  the  os  pubis  to  the  neck  of  the  bladder.  13.  The  edge  of  the  pelvic  fascia  at 
the  point  where  it  is  reflected  upon  the  rectum.  14.  An  interval  between  the  pelvic 
fascia  arid  deep  perineal  fascia,  occupied  by  a  plexus  of  veins.  15.  The  deep  perineal 
fn.-cia;  its  two  layers.  16.  Cowper's  gland  of  the  right  side,  situated  between  the  two 
layers  below  the  membranous  portion  of  the  urethra.  17.  The  superficial  perineal 
fascia,  ascending  in  front  of  the  root  of  the  penis  to  become  continuous  with  the  dartos 
of  the  scrotum  (18).  19.  The  layer  of  the  deep  fascia  which  is  prolonged  to  the  rectum. 
20.  The  lower  part  of  the  levator  ani ;  its  fibres  are  concealed  by  the  anal  fascia.  21. 
The  inferior  segment  of  the  funnel-shaped  process  given  off  from  the  posterior  layer  of 
the  deep  perineal  fascia,  which  is  continuous  with  the  recto-vesical  fascia  of  Tyrrell. 
The  attachment  of  this  fascia  to  the  recto-vesical  fold  of  peritoneum  is  seen  at  2v? 


272  FASCLE    OF   THE    LOWER    EXTREMITY. 

fascia  is  strengthened  at  its  point  of  division  into  slips,  by  strong  fasciculi 
of  transverse  fibres,  and  the  arched  interval  left  between  the  slips  gives 
passage  to  the  tendons  of  the  flexor  muscles.  The  arches  between  the 
fingers  transmit  the  digital  vessels  and  nerve,  and  lumbricales  muscles. 

FASCIJE    OF    THE    LOWER    EXTREMITY. 

The  superficial  fascia  contains  between  its  two  layers  the  superficial 
vessels  and  nerves  of  the  lower  extremity.  At  the  groin  these  two  layers 
are  separated  from  each  other  by  the  superficial  lymphatic  glands,  and  the 
deep  layer  is  attached  to  Poupart's  ligament,  while  the  superficial  layer  is 
continuous  with  the  superficial  fascia  of  the  abdomen. 

The  deep  fascia  of  the  thigh  is  named,  from  its  great  extent,  \he  fascia 
lata;  it  is  thick  and  strong  upon  the  outer  side  of  the  limb,  and  thinner 
upon  its  posterior  side.  That  portion  of  fascia  which  invests  the  gluteus 
maximus  is  very  thin,  but  that  which  covers  in  the  gluteus  medius  is  ex- 
cessively thick,  and  gives  origin  by  its  inner  surface,  to  the  superficial 
fibres  of  that  muscle.  The  fascia  lata  is  attached  superiorly  to  Poupart's 
ligament,  the  crest  of  the  ilium,  sacrum,  coccyx,  tuberosity  of  the  ischium, 
ramus  of  the  ischium,  and  pubes ;  in  the  thigh  it  is  inserted  into  the  linea 
aspera,  and  around  the  knee  is  connected  with  the  prominent  points  of 
that  joint.  It  possesses  also  two  muscular  attachments,  by  means  of  the 
tensor  vaginae  femoris,  which  is  inserted  between  its  two  layers  on  the 
outer  side,  and  the  gluteus  maximus,  which  is  attached  to  it  behind. 

In  addition  to  the  smaller  openings  in  the  fascia  lata  which  transmit  the 
small  cutaneous  vessels  and  nerves,  there  exists  at  the  upper  and  inner 
extremity  of  the  thigh,  an  oblique  foramen,  which  gives  passage  to  the 
superficial  lymphatic  vessels,  and  the  large  subcutaneous  vein  of  the  lower 
extremity,  the  internal  saphenous  vein,  and  is  thence  named  the  saphenous 
opening.  The  existence  of  this  opening  has  given  rise  to  the  division  of 
the  upper  part  of  the  fascia  lata  into  two  portions,  an  iliac  portion  and  a 
pubic  portion. 

The  iliac  portion  is  situated  upon  the  iliac  side  of  the  opening.  It  is 
attached  to  the  crest  of  the  ilium,  and  along  Poupart's  ligament  to  the 
spine  of  the  os  pubis,  whence  it  is  reflected  downwards  and  outwards,  in 
an  arched  direction,  and  forms  a  falciform  border,  which  constitutes  the 
outer  boundary  of  the  saphenous  opening.  The  edge  of  this  border  im- 
mediately overlies,  and  is  reflected  upon  the  sheath  of  the  femoral  vessels, 
and  the  lower  extremity  of  the  curve  is  continuous  with  the  pubic  portion. 

The  pubic  portion,  occupying  the  pubic  side  of  the  saphenous  opening, 
is  attached  to  the  spyie  of  the  os  pubis  and  pectineal  line ;  and,  passing 
outwards  behind  the  sheath  of  the  femoral  vessels,  divides  into  two  layers ; 
the  anterior  layer  is  continuous  with  that  portion  of  the  iliac  fascia  which 
forms  the  sheath  of  the  iliacus  and  psoas  muscles,  and  the  posterior  layer 
is  lost  upon  the  capsule  of  the  hip  joint. 

The  interval  between  the  falciform  border  of  the  iliac  portion  and  the 
opposite  surface  of  the  pubic  portion  is  closed  by  a  fibrous  layer,  which  is 
pierced  by  numerous  openings  for  the  passage  of  lymphatic  vessels,  and  is 
thence  named  cribriform  fascia.  The  cribriform  fascia  is  connected  with 
the  sheath  of  the  femoral  vessels,  and  forms  one  of  the  coverings  of  femoral 
hernia.  When  the  iliac  portion  of  the  fascia  lata  is  removed  from  its  at- 
tachment to  Poupart's  ligament  and  is  turned  aside,  the  sheath  of  the 
vessels  (the  femoral  or  crural  canal)  is  brought  into  view ;  and  if 


FEMORAL    HERNIA. 


273 


Poupart's    ligament    be    carefully  Fig.  144.« 

divided,  the  sheath  may  be  isolated, 
and  its  continuation  with  the  trans- 
versalis  and  iliac  fascia  clearly  de- 
monstrated. In  this  view  the  sheath 
of  the  femoral  vessels  is  an  infundi- 
buliform  continuation  of  the  abdo- 
minal fasciee,  closely  adherent  to  the 
vessels  a  little  way  down  the  thigh, 
but  much  larger  than  the  vessels  it 
contains  at  Poupart's  ligament.  If 
the  sheath  be  opened,  the  artery  and 
vein  will  be  found  lying  side  by 
side,  and  occupying  the  outer  two- 
thirds  of  the  sheath,  leaving  an  in- 
fundibuliform  interval  between  the 
vein  and  the  inner  wall  of  the  sheath. 
The  superior  opening  of  this  space 

is  named  the  femoral  ring;  it  is  bounded  in  front  by  Poupart's  ligament, 
behind  by  the  os  pubis,  internally  by  Gimbernat's  ligament,  and  externally 
by  the  femoral  vein.  The  interval  itself  serves  for  the  passage  of  the  super- 
ficial lymphatic  vessels  from  the  saphenous  opening  to  a  lymphatic  gland, 
which  generally  occupies  the  femoral  ring ;  and  from  thence  they  proceed 
into  the  current  of  the  deep  lymphatics.  The  femoral  ring  is  closed  merely 
by  a  thin  layer  of  subserous  areolar  tissue,!  which  retains  the  lymphatic 
gland  in  its  position,  and  is  named  septum  crurale  ;  and  by  the  peritoneum. 
It  follows  from  this  description,  that  the  femoral  ring  must  be  a  weak  point 
in  the  parietes  of  the  abdomen,  particularly  in  the  female,  where  \hefemoral 
arch,  or  space  included  between  Poupart's  ligament  and  the  border  of  the 
pelvis,  is  larger  than  in  the  male,  while  the  structures  which  pass  through 
it  are  smaller.  It  happens  consequently,  that,  if  violent  or  continued 
pressure  be  made  upon  the  abdominal  viscera,  a  portion  of  intestine  may 
be  forced  through  the  femoral  ring  into  the  infundibuliform  space  in  the 
sheath  of  the  femoral  vessels,  carrying  before  it  the  peritoneum  and  the 
septum  crurale, —  this  constitutes  femoral  hernia.  If  the  causes  which 
give  rise  to  the  formation  of  this  hernia  continue,  the  intestine,  unable  to 
extend  further  down  the  sheath,  from  the  close  connexion  of  the  latter 
with  the  vessels,  will  in  the  next  place  be  forced  forwards  through  the 
saphenous  opening  in  the  fascia  lata,  carrying  before  it  two  additional 
coverings,  the  sheath  of  the  vessels,  or  fascia  propria,  and  the  cribriform 

*  A  section  of  the  structures  which  pass  heneath  the  femoral  arch.  1.  Poupart's  liga- 
ment. 2,  2.  The  iliac  portion  of  the  fascia  lata,  attached  along  the  margin  of  the  crest 
of  the  ilium,  and  along  Poupart's  ligament,  as  far  as  the  spine  of  the  os  pubis  (3).  4. 
The  pubic  portion  of  the  fascia  lata,  continuous  at  3  with  the  iliac  portion,  and  passing 
outwards  behind  the  sheath  of  the  femoral  vessels  to  its  outer  border  at  5,  where  it 
divides  into  two  layers  ;  one  is  continuous  with  the  sheath  of  the  psoas  (6)  and  iliacus 
(7)  ;  the  other  (8)  is  lost  upon  the  capsule  of  the  hip  joint  (9).  10.  The  crural  nerve, 
enclosed  in  the  sheath  of  the  psoas  and  iliacus.  11.  Gimbernat's  ligament.  12.  The 
femoral  ring,  within  the  femoral  sheath.  13.  The  femoral  vein.  14.  The  femoial  ar 
tery ;  the  two  vessels  and  the  ring  are  surrounded  by  the  femoral  sheath,  and  thin  septa 
are  sent  between  the  anterior  and  posterior  wall  of  the  sheath,  dividing  the  artery  from 
the  vein,  and  the  vein  from  the  femoral  ring. 

•j-  This  areolar  tissue  is  sometimes  very  considerably  thickened  ff  a  deposit  of  rt 
within  its  areolae,  and  forms  a  thick  stratum  over  the  hernial  st£ 


«>74  FASCIJ2   OF   THE    LEG. 

fascia ;  and  then  curving  upwards  over  Poupart's  ligament,  the  hernia  will 
become  placed  beneath  the  superficial  fascia  and  integument. 

The  direction  which  femoral  hernia  takes  in  its  descent  is  at  first  down- 
wards, i\ien  forwards,  and  then  upwards;  and  in  endeavouring  to  reduce 
it,  the  application  of  the  taxis  must  have  reference  to  this  course,  and  be 
directed  in  precisely  the  reverse  order.  The  coverings  of  femoral  hernia 
are  the 

Integument,  Fascia  propria, 

Superficial  fascia,  Septum  crurale, 

Cribriform  fascia,  Peritoneal  sac. 

The  FASCIA  OF  THE  LEG  is  strong  in  the  anterior  tibial  region,  and  gives 
•origin  by  its  inner  surface  to  the  upper  part  of  the  tibialis  anticus,  and  ex- 
tensor longus  digitorum  muscles. 

It  is  firmly  attached  to  the  tibia  and  fibula  at  each  side,  and  becomes 
thickened  inferiorly  into  a  narrow  band,  the  anterior  annular  ligament, 
beneath  which  the  tendons  of  the  extensor  muscles  pass  into  the  dorsum 
of  the  foot,  in  distinct  sheaths  lined  by  synovial  bursae.  Upon  the  outer 
side  it  forms  a  distinct  sheath,  which  envelopes  the  peronei  muscles,  and 
ties  them  to  the  fibula.  The  anterior  annular  ligament  is  attached  by  one 
extremity  to  the  outer  side  of  the  os  calcis,  and  divides  in  front  of  the 
joint  into  two  bands ;  one  of  which  is  inserted  into  the  inner  malleolus, 
while  the  other  spreads  over  the  inner  side  of  the  foot,  and  becomes  con- 
tinuous with  the  internal  portion  of  the  plantar  fascia. 

The  fasda  of  the  dorsum  of  the  foot  is  a  thin  layer  given  off  from  the 
lower  border  of  the  anterior  annular  ligament :  it  is  continuous  at  each 
side  with  the  lateral  portions  of  the  plantar  fascia. 

The  fascia  of  the  posterior  part  of  the  leg  is  much  thinner  than  the  ante- 
rior, and  consists  of  two  layers,  superficial  and  deep.  The  superficial 
layer  is  continuous  with  the  posterior  fascia  of  the  thigh,  and  is  increased 
in  thickness  upon  the  outer  side  of  the  leg  by  an  expansion  derived  from 
the  tendon  of  the  biceps ;  it  terminates  inferiorly  in  the  external  and  in- 
ternal annular  ligaments.  The  deep  layer  is  stretched  across  between  the 
tibia  and  fibula,  and  forms  the  intermuscular  fascia  between  the  superficial 
and  deep  layer  of  muscles.  It  covers  in  superiorly  the  popliteus  muscle, 
receiving  a  tendinous  expansion  from  the  semi-membranosus  muscle,  and 
is  attached  to  the  oblique  line  of  the  tibia. 

The  internal  annular  ligament  is  a  strong  fibrous  band,  attached  above 
to  the  internal  malleolus,  and  below  to  the  side  of  the  inner  tuberosity  of 
the  os  calcis.  It  is  continuous  above  with  the  posterior  fascia  of  the  leg, 
and  below  with  the  plantar  fascia,  forming  sheaths  for  the  passage  of  the 
flexor  tendons  and  vessels  into  the  sole  of  the  foot. 

The  external  annular  ligament,  shorter  than  the  internal,  extends  from 
the  extremity  of  the  outer  malleolus  to  the  side  of  the  os  calcis,  and  serves 
to  bind  down  the  tendons  of  the  peronei  muscles  in  their  passage  beneath 
the  external  ankle. 

The  PLANTAR  FASCIA  consists  of  three  portions,  a  middle  and  two 
lateral. 

The  middle  portion  is  thick  and  dense,  and  is  composed  of  strong  apo- 
neurotic  fibres,  closely  interwoven  with  each  other.  It  is  attached  poste- 
riorly to  the  inner  tuberosity  of  the  os  calcis,  and  terminates  under  the 
heads  of  the  metatarsal  bones  in  five  fasciculi.  Each  of  these  fasciculi 


ON    THE   ARTERIES.  275 

divides  into  two  slips,  which  are  inserted  one  on  each  side  into  the  bases 
of  the  first  phalanges  of  the  toes,  leaving  an  interval  between  them  for  the 
passage  of  the  flexor  tendons.  The  point  of  division  of  this  fascia  into 
fasciculi  and  slips,  is  strengthened  by  transverse  bands,  which  preserve 
the  solidity  of  the  fascia  at  its  broadest  part.  The  intervals  between  the 
toes  give  passage  to  the  digital  arteries  and  nerves,  and  to  the  lumbricales 
muscles. 

The  lateral  portions  are  thin,  and  cover  the  sides  of  the  sole  of  the  foot ; 
they  are  continuous  behind  with  the  internal  and  external  annular  liga- 
ments ;  on  the  inner  side  with  the  middle  portion,  and  externally  with  the 
dorsal  fascia. 

Besides  constituting  a  strong  layer  of  investment  and  defence  to  the  soft 
parts  situated  in  the  sole  of  the  foot,  these  three  portions  of  fascia  send 
processes  inwards,  which  form  sheaths  for  the  different  muscles.  A  strong 
septum  is  given  off  from  each  side  of  the  middle  portion  of  the  plantar 
fascia,  which  is  attached  to  the  tarsal  bones,  and  divides  the  muscles  into 
three  groups,  a  middle  and  two  lateral ;  and  transverse  septa  are  stretched 
between  these  to  separate  the  layers.  The  superficial  layer  of  muscles 
derive  a  part  of  their  origin  from  the  plantar  fascia. 


CHAPTER    VI. 

ON  THE  ARTERIES. 

THE  arteries  are  the  cylindrical  tubes  which  convey  the  blood  from  the 
ventricles  of  the  heart  to  every  part  of  the  body.  They  are  dense  in  struc- 
ture, and  preserve  for  the  most  part  the  cylindrical  form  when  emptied  of 
their  blood,  which  is  their  condition  after  death :  hence  they  were  con- 
sidered by  the  ancients  as  the  vessels  for  the  transmission  of  the  vital 
spirits,*  and  were  therefore  named  arteries  (aty  T^SIV,  to  contain  air). 

The  artery  proceeding  from  the  left  ventrical  of  the  heart  contains  the 
pure  or  arterial  blood,  which  is  distributed  throughout  the  entire  system, 
and  constitutes,  with  its  returning  veins,  the  greater  or  systemic  circula- 
tion. That  which  emanates  from  the  right  ventricle,  conveys  the  impure 
blood  to  the  lungs ;  and,  with  its  corresponding  veins,  establishes  the 
lesser  or  pulmonary  circulation. 

The  whole  of  the  arteries  of  the  systemic  circulation  proceed  from  a 
single  trunk,  named  the  aorta,  from  which  they  are  given  off  as  branches, 
and  divide  and  subdivide  to  their  ultimate  ramifications,  constituting  the 
great  arterial  tree  which  pervades,  by  its  minute  subdivisions,  every  part 
of  .the  animal  frame.  The  mode  in  which  the  division  into  branches  takes 
place,  is  deserving  of  remark.  From  the  aorta,  the  branches,  for  the  most 
part,  pass  off  at  right  angles,  as  if  for  the  purpose  of  checking  the  impetus 
with  which  the  blood  would  otherwise  rush  along  their  cylinders  from  the 
main  trunk ;  but  in  the  limbs  a  very  different  arrangement  is  adopted ; 
the  branches  are  given  off  from  the  principal  artery  at  an  acute  angle,  so 

*  To  Galen  is  due  the  honour  of  having  discovered  that  arteries  contained  blood,  awl 
not  air. 


276  GENERAL   ANATOiMY   OF   ARTERIES. 

that  no  impediment  may  be  offered  to  the  free  circulation  of  the  vital  fluid. 
The  division  of  arteries  is  usually  dichotomous,  as  of  the  aorta  into  the 
two  common  iliacs,  common  carotid  into  the  external  and  internal,  &c. ; 
but  in  some  few  instances  a  short  trunk  divides  suddenly  into  several 
branches,  which  proceed  in  different  directions ;  this  mode  of  division  is 
termed  an  axis,  as  the  thyroid  and  cceliac  axis. 

In  the  division  of  an  artery  into  two  branches,  it  is  observed  that  th 
combined  areoe  of  the  two  branches  are  somewhat  greater  than  that  of  th 
single  trunk ;  and  if  the  combined  arese  of  all  the  branches  at  the  peri 
phery  of  the  body  were  compared  with  that  of  the  aorta,  it  would  be  seen 
that  the  blood,  in  passing  from  the  aorta  into  the  numerous  distributing 
branches,  was  flowing  through  a  conical  space,  of  which  the  apex  might 
be  represented  by  the  aorta,  and  the  base  by  the  surface  of  the  body. 
The  advantage  of  this  important  principle  in  facilitating  the  circulation  is 
sufficiently  obvious ;  for  the  increased  channel  which  is  thus  provided  for 
the  current  of  the  blood,  serves  to  compensate  for  the  retarding  influence 
of  friction,  resulting  from  the  distance  of  the  heart  and  the  division  of  the 
vessels. 

Communications  between  arteries  are  very  free  and  numerous,  and  in- 
crease in  frequency  with  the  diminution  in  size  of  the  branches ;  so  that, 
through  the  medium  of  the  minute  ramifications,  the  entire  body  may  be 
considered  as  one  uninterrupted  circle  of  inosculations,  or  anastomoses 
(dva  between,  oVo'fjia  mouth).  This  increase  in  the  frequency  of  anastomosis 
in  the  smaller  branches  is  a  provision  for  counteracting  the  greater  liability 
to  impediment  existing  in  them  than  in  the  larger  branches.  Where  free- 
dom of  circulation  is  of  vital  importance,  this  communication  of  the  arteries 
is  very  remarkable,  as  in  the  circle  of  Willis  in  the  cranium,  or  in  the  dis- 
tribution of  the  arteries  of  Ihe  heart.  It  is  also  strikingly  seen  in  situations 
where  obstruction  is  most  likely  to  occur,  as  in  the  distribution  to  the  ali- 
mentary canal,  around  joints,  or  in  the  hand  and  foot.  Upon  this  free 
communication  existing  everywhere  between  arterial  branches  is  founded 
the  principle  of  cure  in  the  ligature  of  large  arteries ;  the  ramifications  of 
the  branches  given  off  from  the  artery  above  the  ligature  inosculate  with 
those  which  proceed  from  the  trunk  of  the  vessel  below  the  ligature ;  these 
anastomosing  branches  enlarge  and  constitute  a  collateral  circulation,  in 
which,  as  is  shown  in  the  beautifiul  preparations  made  by  Sir  Astley 
Cooper,  several  large  branches  perform  the  office  of  the  single  obliterated 
trunk.* 

The  arteries  do  not  terminate  directly  in  veins  ;  but  in  an  intermediate 
system  of  vessels,  which,  from  their  minute  size  (about  g^Va  of  an  inch  in 
diameter),  are  termed  capillaries  (capillus,  a  hair).  The  capillaries  con- 
stitute a  microscopic  network,  which  is  distributed  through  every  part  of 
the  body,  so  as  to  render  it  impossible  to  introduce  the  smallest  needle 
point  beneath  the  skin  without  wounding  several  of  these  fine  vessels.  It 
is  through  the  medium  of  the  capillaries,  that  all  the  phenomena  of  nutri- 
tion and  secretion  are  performed.  They  are  remarkable  for  their  unifor- 
mity of  diameter,  and  for  the  constant  divisions  and  communications 
which  take  place  between  them,  without  any  alteration  of  size.  They 

•  I  have  a  preparation,  showing  the  collateral  circulation  in  a  dog,  in  which  I  tied 
Uie  abdominal  aorta;  the  animal  died  from  over-feeding  nearly  two  years  after  the 
operation 


STRUCTURE    OF    ARTERIES.  277 

inosculate  on  the  one  hand  with  the  terminal  ramusculi  of  the  arteries ; 
and  on  the  other  widi  the  minute  radicles  of  the  veins. 

Arteries  are  composed  of  three  coats,  external,  middle,  and  internal. 
The  external  or  areolo-jibrous  coat  is  firm  and  strong,  and  serves  at  the 
same  time  as  the  chief  means  of  resistance  of  the  vessel,  and  of  connection 
to  surrounding  parts.  It  consists  of  condensed  areolo-fibrous  tissue, 
strengthened  by  an  interlacement  of  glistening  fibres  which  are  partly 
ongitudinal  and  partly  encircle  the  cylinder  of  the  tube  in  an  oblique 
direction.  Upon  the  surface  the  areolar  tissue  is  loose,  to  permit  of  the 
movements  of  the  artery  in  distention  and  contraction. 

The  middle  coat  is  that  upon  which  the  thickness  of  the  artery  depends; 
it  is  yellowish  in  colour,  and  so  brittle  as  to  be  cut  through  by  the  thread 
in  the  ligature  of  a  vessel.* 

The  internal  coat  is  a  thin  serous  membrane  which  lines  the  interior  of 
the  artery,  and  gives  it  the  smooth  polish  which  that  surface  presents.  It 
is  continuous  with  the  lining  membrane  of  the  heart,  and  through  the  me- 
dium of  the  capillaries  with  that  of  the  venous  system. 

In  intimate  structure  an  artery  is  more  complicated  than  the  above  de- 
scription wrould  imply.  The  internal  coat,  for  example,  is  composed  of 
two  layers,  and  the  middle  of  three,  so  that,  with  the  external  coat,  there 
are  six  layers  entering  into  the  composition  of  an  artery.  The  innermost 
coat  is  a  tesselated  epithelium  analogous  to  that  of  other  serous  membranes. 
The  second  coat  from  within  is  a  thin,  rigid  membrane,  pierced  with  a 
number  of  round  or  oval-shaped  holes,  and  supporting  a  thin  layer  of  flat, 
longitudinal  fibres.  From  these  characters  it  has  been  denominated  the 
fenestrated  or  striated  coat.  The  third  layer,  which  is  the  innermost  part 
of  the  middle  coat,  is  composed  of  flat,  longitudinal  fibres,  analogous  to 
those  of  organic  muscle.  The  fourth  layer,  the  thickest  of  the  whole,  is 
composed  of  muscular  fibres  of  organic  life,  arranged  in  a  circular  direc- 
tion around  the  vessel.  The  fifth,  or  outermost  part  of  the  middle  coat, 
is  a  thin  layer  of  elastic  tissue ;  this  is  present  only  in  the  large  arteries. 
The  sixth  is  the  external  or  areolo-fibrous  coat. 

The  arteries  in  their  distribution  through  the  body  are  included  in  a 
loose  areolar  investment  which  separates  them  from  surrounding  tissues, 
and  is  called  a  sheath.  Around  the  principal  vessels  the  sheath  is  an  im- 
portant structure ;  it  is  composed  of  areolo-fibrous  tissue,  intermingled 
with  tendinous  fibres,  and  is  continuous  with  the  fasciae  of  the  region  in 
which  the  arteries  are  situated,  as  with  the  thoracic  and  cervical  fascia?  in 
the  neck,  transversalis  and  iliac  fasciae,  and  fascia  lata  in  the  thigh,  &c. 
The  sheath  of  the  arteries  contains  also  their  accompanying  veins,  and 
sometimes  a  nerve. 

The  coats  of  arteries  are  supplied  with  blood  like  other  organs  of  the 
body,  and  the  vessels  which  are  distributed  to  them  are  named  vasa  vaso- 
rum.  They  are  also  provided  with  nerves ;  but  the  mode  of  distribution 
of  the  nerves  is  at  present  unknown. 

In  the  consideration  of  the  arteries,  we  shall  first  describe  the  aorta,  and 

*  The  second  or  middle  coat  of  the  arteries  has  given  rise  to  no  little  discussion  among 
the  continental  anatomists.  It  will  be  found,  however,  to  consist  of  fibres,  flat,  elastic, 
for  the  most  part  transverse,  and  belonging  to  the  yellow  elastic  tissue.  Some  of  the 
fibres  are  longitudinal,  and  some  of  the  transverse  present  strong  evidences  of  belonging 
to  the  muscular  system  of  organic  life  ;  so  that  the  coat  may,  I  think,  be  fairly  staled  to 
be  a  mixed  one,  composed  of  yellow,  elastic,  and  organic  muscular  fibres.  *.t  Is  best 
studied  in  tVe  aorta  or  some  large  trunk. — G. 

24 


278  AORTA. 

the  branches  of  that  trunk  with  their  subdivisions,  which  together  consti- 
tute the  efferent  portion  of  the  systemic  circulation ;  and  then  the  pul- 
monary artery  as  the  efferent  trunk  of  the  pulmonary  circulation. 

Fig.  145.» 


AORTA. 

The  AORTA  arises  from  the  left  ventricle,  at  the  middle  of  the  root  of  the 
heart,  and  opposite  the  articulation  of  the  fourth  costal  cartilage  with  the 
sternum.  At  its  commencement  it  presents  three  dilatations,  called  the 
sinus  aortici,  which  correspond  with  the  three  semilunar  valves.  It  as- 
cends at  first  to  the  right,  then  curves  backwards  and  to  the  left,  and  de- 
scends on  the  left  side  of  the  vertebral  column  to  the  fourth  lumbar  verte- 
bra. Hence  it  is  divided  into — ascending — arch — and  descending  aorta. 

*  The  large  vessels  which  proceed  from  the  root  of  the  heart,  with  their  relations  ; 
the  heart  has  been  removed.  1.  The  ascending  aorta.  2.  The  arch.  3.  The  thoracic 
portion  of  the  descending  aorta.  4.  The  arteria  innominata,  dividing  into,  5,  the  right 
carotid,  which  again  divides  at  6,  into  the  external  and  internal  carotid  ;  and  7,  the 
right  subdavian  artery.  8.  The  axillary  artery;  its  extent  is  designated  by  a  dotted 
line.  9.  The  brachial  artery.  10.  The  right  pneumogastric  nerve  running  by  the  side 
of  the  common  carotid,  in  front  of  the  right  subclavkin  artery,  and  behind  the  root  of 
the  right  lung.  11.  The  left  common  carotid,  having  to  its  outer  side  the  left  pneumo- 
gastric nerve,  which  crosses  the  arch  of  the  aorta,  and  as  it  reaches  its  lower  border  is 
seen  to  give  off  the  left  recurrent  nerve.  12.  The  left  subclavian  artery  becoming  axil- 
lary and  brachial  in  its  course,  like  the  artery  of  the  opposite  side.  13.  The  trunk  of 
the  pulmonary  artery  connected  to  the  concavity  of  the  arch  of  the  aorta  by  a  fibrous 
cord,  the  remains  of  the  ductus  arteriosus.  14.  The  left  pulmonary  artery.  15.  The 
right  pulmonary  artery.  16.  The  trachea.  17.  The  right  bronchus.  18.  The  left 
bronchus.  19,  19.  The  pulmonary  veins.  17,  15,  and  19,  on  the  right  side,  and  14,  18, 
and  19,  on  the  left,  constitute  the  roots  of  the  corresponding  lungs,  and  the  relative  posi- 
tion of  these  vessels  is  preserved.  20.  Bronchial  arteries.  21,  21.  Intercostal  arteries; 
the  branches  from  the  front  of  the  aorta  above  and  below  the  number  3  are  pericardiao 
and  oesopbageal  branches. 


ARCH    OF    THE    AORTA.  27U 

Relations. — The  ascending  aorta  has  in  relation  with  it,  in  front,  the 
trunk  of  the  pulmonary  artery,  thoracic  fascia,  and  pericardium ;  behind, 
the  right  pulmonary  veins  and  artery ;  to  the  right  side,  the  right  auricle 
and  superior  cava ;  and  to  the  left,  the  left  auricle  and  the  trunk  of  the 
pulmonary  artery. 

Plan  of  the  Relations  of  the  Ascending  Aorta. 

In  Front. 
Pericardium, 


Thoracic  fascia, 
Pulmonary  artery. 


Right  Side. 

Superior  cava, 
Right  auricle. 


Ascending  Aorta. 


Left  Side. 

Pulmonary  artery. 
Left  auricle. 


Behind. 

Right  pulmonary  artery, 
Right  pulmonary  veins. 

Arch. — The  upper  border  of  the  arch  of  the  aorta  is  parallel  with  tta 
upper  border  of  the  second  sterno-costal  articulation  of  the  right  side  m 
front,  and  the  second  dorsal  vertebra  behind,  and  terminates  opposite  the 
lower  border  of  the  third. 

The  anterior  surface  of  the  arch  is  crossed  by  the  left  pneumogastric 
nerve,  and  by  the  cardiac  branches  of  that  nerve  and  of  the  sympathetic. 
The  posterior  surface  of  the  arch  is  in  relation  with  the  bifurcation  of  the 
trachea  and  great  cardiac  plexus,  the  cardiac  nerves,  left  recurrent  nerve, 
and  the  thoracic  duct.  The  superior  border  gives  off  the  three  great  arte- 
ries, viz.  the  innominata,  left  carotid,  and  left  subclavian.  The  inferior 
border,  or  concavity  of  the  arch,  is  in  relation  with  the  remains  of  the 
ductus  arteriosus,  the  cardiac  ganglion  and  left  recurrent  nerve,  and  has 
passing  beneath  it  the  right  pulmonary  artery  and  left  bronchus. 

Plan  of  the  Relations  of  the  Arch  of  the  Aorta. 

Move. 

Arteria  innominata, 
Left  carotid, 
Left  subclavian. 

In  Front.  __^^_  Behind. 

Bifurcation  of  the  trachea, 


Left  pneumogastric 

nerve, 
Cardiac  nerves. 


Arch  of  the  Aorta, 


Great  cardiac  plexus, 
Cardiac  nerves, 
Left  recurrent  nerve, 
Thoracic  duct. 


Below. 

Cardiac  ganglion, 
Remains  of  ductus  arteriosus, 
Left  recurrent  nerve, 
Right  pulmonary  artery, 
Left  bronchus. 


The  descending  aorta  is  subdivided  in  correspondence  with  the  two 
great  cavities  of  the  trunk,  into  the  thoracic  and  abdominal  aorta. 


280  ABDOMINAL    AORTA. 

The  THORACIC  AORTA  is  situated  to  the  left  side  of  the  vertebral  column, 
but  approaches  the  middle  line  as  it  descends,  and  at  the  aortic  opening 
of  the  diaphragm  is  altogether  in  front  of  the  column.  After  entering  the 
abdomen  it  again  falls  back  to  the  left  side. 

Relations. — It  is  in  relation,  behind,  \vith  the  vertebral  column  and 
lesser  vena  azygos ;  in  front,  with  the  ossophagus  and  right  pneumogastrie 
nerve ;  to  the  left  side,  with  the  pleura ;  and  to  the  right,  with  the  thoracic 
duct. 

Plan  of  the  Relations  of  the  Thoracic  Aorta. 

In  Front. 


(Esophagus, 

Right  pneumogastrie  nerve. 


Right  Side. 
Thoracic  duct. 


Thoracic  Aorta. 


Left  Side. 
Pleura. 


Behind. 

Lesser  vena  azygos, 
Vertebral  column. 

The  ABDOMINAL  AORTA  enters  the  abdomen  through  the  aortic  opening 
of  the  diaphragm,  and  descends,  lying  rather  to  the  left  side  of  the  verte- 
bral column,  to  the  fourth  lumbar  vertebra,  where  it  divides  into  the  two 
common  iliac  arteries. 

Relations. — It  is  crossed  in  front,  by  the  left  renal  vein,  pancreas,  trans- 
verse duodenum,  and  mesentery,  and  is  embraced  by  the  aortic  plexus ; 
behind  it  is  in  relation  with  the  thoracic  duct,  receptaculum  chyli,  and  left 
lumbar  veins. 

On  its  left  side  is  the  left  semilunar  ganglion  and  sympathetic  nerve  ; 
and  on  the  right,  the  vena  cava,  right  semilunar  ganglion,  and  the  com- 
mencement of  the  vena  azygos. 

Plan  of  the  Relations  of  the  Abdominal  Aorta. 

In  Front. 

Left  renal  vein, 

Pancreas, 

Transverse  duodenum, 

Mesentery, 

Aortic  plexus. 


Right  Side. 
Vena  cava, 
Kight  semilunar  gan- 
glion, 
Vena  azygos. 


Abdominal  Aorta. 


Left  Side. 

Left  semilunar  gan- 
glion, 
Sympathetic  ne've 


Behind. 

Thoracic  duct, 
Receptaculum  chyli, 
Left  lumbar  veins. 


Thoracic  aorta 


.Abdominal  aorta 


ARTERIA    INNOMINATA.  281 

Branches. — The  branches  of  the  aorta,  arranged  into  a  tabular  form, 
are, — 

Ascending  aorta     .     .         Coronary. 

(  Arteria  innominata,  '  carotl">. 

Arch  of  the  aorta  .     .      3  Left  carotid,  *  Rlght  subclavian. 

f  Left  subclavian. 
Pericardiac, 
Bronchial, 
CEsophageal, 
Intercostal. 
Phrenic, 

C  Gastric, 
Goalie  axis,  <  Hepatic, 

(  Splenic. 
Supra-renal, 
Renal, 

Superior  mesenteric, 
Spermatic, 
Inferior  mesenteric, 
Lumbar, 
Sacramedia, 
Common  iliacs. 

The  CORONARY  ARTERIES  arise  from  the  aortic  sinuses  at  the  commence- 
ment of  the  ascending  aorta,  immediately  above  the  free  margin  01  the 
semilunar  valves.  The  left  or  anterior  coronary,  passes  forwards,  be 
tween  the  pulmonary  artery  and  left  appendix  auriculas,  and  divides  into 
two  branches;  one  of  which  winds  around  the  base  of  the  left  ventricle  in 
the  auriculo-ventricular  groove,  and  inosculates  with  the  right  coronary, 
forming  an  arterial  circle  around  the  base  of  the  heart ;  while  the  other 
passes  along  the  line  of  union  of  the  two  ventricles,  upon  the  anterior  as- 
pect of  the  heart,  to  its  apex,  where  it  anastomoses  with  the  descending 
branch  of  the  right  coronary.  It  supplies  the  left  auricle  and  the  anterior 
surface  of  both  ventricles. 

The  right,  or  posterior  coronary,  passes  forwards,  between  the  root  of 
the  pulmonary  artery  and  the  right  auricle,  and  winds  along  the  auriculo- 
ventricular  groove,  to  the  posterior  median  furrow,  where  it  descends  upon 
the  posterior  aspect  of  the  heart  to  its  apex,  and  inosculates  with  the  left 
coronary.  It  is  distributed  to  the  right  auricle,  and  to  the  posterior  surface 
of  both  ventricles,  and  sends  a  large  branch  along  the  sharp  margin  of  the 
right  ventricle  to  the  apex  of  the  heart. 

ARTERIA    INNOMINATA. 

The  Arteria  innominata  (fig.  145,  No.  4)  is  the  first  artery  given  off  by 
the  arch  of  the  aorta.  It  is  an  inch  and  a  half  in  length,  and  ascends 
obliquely  towards  the  right  sterno-clavicular  articulation,  where  it  divides 
into  the  right  carotid  and  right  subclavian  artery. 

Relations. — It  is  in  relation,  in  front,  with  the  left  vena  innominata,  the 
thymus  gland,  and  the  origins  of  the  sterno-thyroid  and  sterno-hyoid  mus- 
cles, which  separate  it  from  the  sternum.  Behind,  with  the  trachea,  pneu- 
24* 


282  COMMON    CAROTID    ARTERIES. 

mogastric  nerve  and  cardiac  nerves ;  externally,  with  the  right  vena  inno- 
ininata  and  pleura ;  and  internally,  with  the  origin  of  the  left  carotid. 

Plan  of  the  Relations  of  the  Arteria  Innominata. 

In  Front. 
Left  vena  innominata, 


Tliymus  eland, 
Sterno-thyroid, 
Sterno-hyoid. 


Right  Side. 

Ri^ht  vena  innominata, 
Pleura. 


Arteria  innominata. 


Left  Side. 
Left  carotid. 


Behind. 
Trachea, 

Pneumogastric  nerve, 
Cardiac  nerves. 

The  arteria  innominata  occasionally  gives  off  a  small  branch,  which 
ascends  along  the  middle  of  the  trachea  to  the  thyroid  gland.  This  branch 
was  described  by  Neubauer,  and  Dr.  Harrison  names  it  the  middle  thyroid 
artery.  A  knowledge  of  its  existence  is  important  in  performing  the  ope- 
ration of  tracheotomy. 

COMMON    CAROTID   ARTERIES. 

The  common  carotid  arteries  (xapa,  the  head,)  arise,  the  right  from  the 
bifurcation  of  the  arteria  innominata  opposite  the  right  sterno-clavicular 
articulation,  the  left  from  the  arch  of  the  aorta.  It  follows,  therefore,  that 
the  right  carotid  is  shorter  than  the  left ;  it  is  also  more  anterior;  and,  in 
consequence  of  proceeding  from  a  branch  instead  of  from  the  main  trunk, 
it  is  larger  than  its  fellow. 

The  Right  common  carotid  artery  (fig.  145,  No.  5)  ascends  the  neck 
perpendicularly,  from  the  right  sterno-clavicular  articulation  to  a  level  with 
the  upper  border  of  the  thyroid  cartilage,  where  it  divides  into  the  external 
and  internal  carotid. 

The  Left  common  carotid  (fig.  145,  No.  11)  passes  somewhat  obliquely 
outwards  from  the  arch  of  the  aorta  to  the  side  of  the  neck,  and  thence 
upwards  to  a  level  with  the  upper  border  of  the  thyroid  cartilage,  where  it 
divides  like  the  right  common  carotid  into  the  external  and  internal  carotid. 

Relations. — The  right  common  carotid  rests,  first,  upon  the  longus  colli 
muscle,  then  upon  the  rectus  anticus  major,  the  sympathetic  nerve  being 
interposed.  The  inferior  thyroid  artery  and  recurrent  laryngeal  nerve 
pass  behind  it  at  its  lower  part.  To  its  inner  side  is  the  trachea,  recurrent 
laryngeal  nerve,  and  larynx ;  to  its  outer  side,  and  enclosed  in  the  same 
sheath,  the  jugular  vein  and  pneumogastric  nerve ;  and  in  front,  the  sterno- 
thyroid,  sterno-hyoid,  sterno-mastoid,  omo-hyoid,  and  platysma  muscles, 
and  the  descendens  noni  nerve.  The  left  common  carotid,  in  addition  to 
the  relations  just  enumerated,  which  are  common  to  both,  is  crossed  near 
its  commencement  by  the  left  vena  innominata ;  it  lies  upon  the  trachea  ; 
then  gets  to  its  side,  and  is  in  relation  with  the  oesophagus  and  thoracic 
duct :  to  facilitate  the  study  of  these  relations,  I  have  arranged  them  in  a 
(abular  form. 


EXTERNAL  CAROTID  ARTERY. 


283 


Plan  of  Relations  of  the  Common  Carotid  Artery. 

In  Front. 
Platysma, 

Descendens  noni  nerve, 
Omo-hyoid, 
Sterno-mastoid, 
Sterno-hyoid, 
Sterno-thyroid. 


Externally. 

Interna.  jugular  vein, 
Pneumogastric  nerve. 


Common 

Carotid  Artery. 

Internally. 
Trachea, 
Larynx, 
Recurrent  laryngeal  nerve 


Behind. 
Longus  colli, 
Rectus  anticus  major, 
Sympathetic, 
Inferior  thyroid  artery, 
Recurrent  laryngeal  nerve. 

Additional  Relations  of  the  Left  Common  Carotid. 

In  Front.  Behind.  Internally.  Externally 

Left  vena  innominata.  Trachea,  Arteria  innominata,  Pleura. 

Thoracic  duct.  (Esophagus. 


EXTERNAL  CAROTID  ARTERY. 

The  External  carotid  artery  ascends  nearly  perpendicularly  from  oppo- 
site the  upper  border  of  the  thyroid  cartilage,  to  the  space  between  the 
neck  of  the  lower  jaw  and  the  meatus  auditorius,  where  it  divides  into  the 
temporal  and  internal  maxillary  artery. 

Relations.  —  In  front  it  is  crossed  by  the  posterior  belly  of  the  digas- 
tricus,  stylo-hyoideus,  and  platysma  myoides  muscles ;  by  the  hypoglossal 
nerve  near  its  origin ;  higher  up  it  is  situated  in  the  substance  of  the 
parotid  gland,  and  is  crossed  by  the  facial  nerve.  Behind,  it  is  separated 
from  the  internal  carotid  by  the  stylo-pharyngeus  and  stylo-glossus 
muscles,  glosso-pharyngeal  nerve,  and  part  of  the  parotid  gland. 

Plan  of  the  Relations  of  the  External  Carotid  Artery. 

In  Front. 
Platysma, 
Digastricus, 
Stylo-hyoid, 
Hypoglossal  nerve, 
Facial  nerve, 
Parotid  gland. 


External  Carotid  Artery. 


Behind. 

Stylo-pharyngeus, 
Stylo-glossus, 
Glosso-pharyngeal  nerve. 
Parotid  gland. 


284 


SUPERIOR    THYROID    ARTERY. 


Posterior. 

4.  Mastoid, 

5.  Occipital, 

6.  Posterior  auricular. 

Terminal. 

10.  Temporal, 

11.  Internal  maxillary. 


Branches. — The  branches  of  the  external  carotid  are  eleven  in  number, 
anc'  may  be  arranged  into  four  groups,  viz. 

Anterior. 

1.  Superior  thyroid, 

2.  Lingual, 

3.  Facial. 

Superior. 

7.  Ascending  pharyngeal, 

8.  Parotidean, 

9.  Transverse  facial. 

The  anterior  branches  arise  from  the  commencement  of  the  external 
carotid,  within  a  short  distance  of  each  other.  The  lingual  and  facial 
bifurcate,  not  unfrequently,  from  a  common  trunk. 

1.  The  SUPERIOR  THYROID  AHTERY  (the  first  of  the  branches  of  the  ex- 
ternal carotid)  curves  downwards  to  the  thyroid  gland  to  which  it  is  dis- 
tributed, anastomosing  with  its  fellow  of  the  opposite  side,  and  with  the 
inferior  thyroid  arteries.  In  its  course  it  passes  beneath  the  omo-hyoid, 
sterno-thyroid,  and  sterno-hyoid  muscles. 

Fig.  146.» 


Branches. — Hyoid, 

Superior  laryngeal, 
Inferior  laryngeal, 
Muscular. 

•The  carotid  arteries,  with  the  branches  of  the  external  carotid.     1.  The  common 

00.     2.  The  external  carotid.     3.  The  internal  carotid.     4.  The  carotid  foramen  in 

ie  petrous  portion  of  the  temporal  bone.     5.  The  superior  thyroid  artery.     G.  The  lin- 

rtery.     -J    The  facial  artery.     8.  The  mastoid  artery.     9.  The  <v;  pital       10    Tha 

posterior   auricular .     11.   The    transverse    facial   artery.      12.   The   internal    maxillary 

13.  I  he  temporal.     14.  The  ascending  phar/ngeal  artery. 


LINGUAL    AND    FACIAL    ARTERIES.  285 

The  Hyoid  branch  passes  forwards  beneath  the  thyro-hyoideus,  and  is 
distributed  to  the  depressor  muscles  of  the  os  hyoides  near  their  insertion. 

The  Superior  laryngeal  pierces  the  thyro-hyoidean  membrane,  in  com- 
pany with  the  superior  laryngeal  nerve,  and  supplies  the  mucous  mem- 
brane and  muscles  of  the  larynx,  sending  a  branch  upwards  to  the 
epiglottis. 

The  Inferior  laryngeal  is  a  small  branch  which,  crosses  the  crico-thyroi- 
dean  membrane  along  the  lower  border  of  the  thyroid  cartilage.  It  sends 
branches  through  the  membrane,  to  supply  the  mucous  lining  of  the  larynx, 
and  inosculates  with  its  fellow  of  the  opposite  side. 

The  Muscular  branches  are  distributed  to  the  depressor  muscles  of  the 
os  hyoides  and  larynx.  One  of  these  branches  crosses  the  sheath  of  the 
common  carotid  to  the  under  surface  of  the  sterno-mastoid  muscle. 

2.  The  LINGUAL  ARTEBY  ascends  obliquely  from  its  origin,  it  then 
passes  forwards  parallel  with  the  great  cornu  of  the  os  hyoides ;  thirdly,  it 
ascends  to  the  under  surface  of  the  tongue ;  and,  fourthly,  runs  forward 
in  a  serpentine  direction  to  its  tip  (under  the  name  of  the  ranine  artery), 
where  it  terminates  by  inosculating  with  its  fellow  of  the  opposite  side. 

Relations. — The^rs^  part  of  its  course  rests  upon  the  middle  constrictor 
muscle  of  the  pharynx,  being  covered  in  by  the  tendon  of  the  digastricus 
and  the  stylo-hyoid  muscle ;  the  second  is  situated  between  the  middle 
constrictor  and  hyo-glossus  muscle,  the  latter  separating  it  from  the  hypo- 
glossal  nerve ;  in  the  third  part  of  its  course  it  lies  between  the  hyo-glossus 
and  genio-hyo-glossus;  and  in  the  fourth  (ranine)  rests  upon  the  lingualis 
to  the  tip  of  the  tongue. 

Branches. — Hyoid, 

Dorsalis  linguse, 
Sublingual. 

The  Hyoid  branch  runs  along  the  upper  border  of  the  os  hyoides,  and 
is  distributed  to  the  elevator  muscles  of  the  os  hyoides  near  their  origin, 
inosculating  with  its  fellow  of  the  opposite  side. 

The  Dorsalis  linguae,  ascends  along  the  posterior  border  of  the  hyo- 
glossus  muscle  to  the  dorsum  of  the  tongue,  and  is  distributed  to  the 
tongue,  the  fauces,  and  epiglottis,  anastomosing  with  its  fellow  of  the  op- 
posite side. 

The  Sublingual  branch,  sometimes  considered  as  a  branch  of  bifurca- 
tion of  the  lingual,  runs  along  the  anterior  border  of  the  hyo-glossus,  and 
is  distributed  to  the  sublingual  gland  and  to  the  muscles  of  the  tongue. 
It,  is  situated  between  the  mylo-hyoideus  and  genio-hyo-glossus,  generally 
accompanies  Wharton's  duct  for  a  part  of  its  course,  and  sends  a  branch 
to  the  fraenum  linguse.  It  is  the  latter  branch  which  affords  the  consider 
able  haemorrhage  which  sometimes  follows  the  operation  of  snipping  the 
frffinum  in  children. 

3.  FACIAL  ARTERY.  —  The  Facial  artery  arises  a  little  above  the  greai 
cornu  of  the  os  hyoides,  and  descends  obliquely  to  the  submaxillary  gland, 
in  which  it  lies  embedded.     It  then  curves  around  the  body  of  the  lower 
jaw,  close  to  the  anterior  inferior  angle  of  the  masseter  muscle,  ascends 
to  the  anjjle  of  the  mouth,  and  thence  to  the  angle  of  the  eye,  where  it  w 
named  the  angular  artery.     The  facial  artery  is  tortuous  in  its  course 


036  FACIAL   ARTERY. 

over  the  buccinator  muscle,  to  accommodate  itself  to  the  movements  of 
the  jaws. 

Relations. — Below  the  jaw  it  passes  beneath  the  digastncus  and  styio- 
hyoid  muscles ;  on  the  body  of  the  lower  jaw  it  is  covered  by  the  platysma 
myoides,  and  at  the  angle  of  the  mouth  by  the  depressor  anguli  oris  and 
zygomatic  muscles.  It  rests  upon  the  submaxillary  gland,  the  lower  jaw, 
buccinator,  orbicularis  oris,  levator  anguli  oris,  levator  labii  superioris 
proprius,  and  levator  labii  superioris  alseque  nasi. 

Its  branches  are  divided  into  those  which  are  given  off  below  the  jaw 
and  those  on  the  face :  they  may  be  thus  arranged : — 

Below  the  Jaw. — Inferior  palatine, 
Submaxillary, 
Submental, 
Pterygoid. 

On  the  Face. — Masseteric, 

Inferior  labial, 
Inferior  coronary, 
Superior  coronary, 
Lateralis  nasi. 

The  Inferior  palatine  branch  ascends  between  the  stylo-glossus  and 
stylo-pharyngeus  muscles,  to  be  distributed  to  the  tonsil  and  soft  palate, 
and  anastomoses  with  the  posterior  palatine  branch  of  the  internal  maxil- 
lary artery. 

The  Submaxillary  are  four  or  five  branches  which  supply  the  submaxil- 
lary gland. 

The  Submental  branch  runs  forwards  upon  the  mylo-hyoid  muscle,  under 
cover  of  the  body  of  the  lower  jaw,  and  anastomoses  with  branches  of  the 
sublingual  and  inferior  dental  artery. 

The  Pterygoid  branch  is  distributed  to  the  internal  pterygoid  muscle. 

The  Masseteric  branches  are  distributed  to  the  masseter  and  buccinator 
muscles. 

The  Inferior  labial  branch  is  distributed  to  the  muscles  and  integument 
of  the  lower  lip. 

The  Inferior  coronary  runs  along  the  edge  of  the  lower  lip,  between  the 
mucous  membrane  and  the  orbicularis  oris ;  it  inosculates  with  the  cor- 
responding artery  of  the  opposite  side. 

The  Superior  coronary  follows  the  same  course  along  the  upper  lip,  in- 
osculating with  the  opposite  superior  coronary  artery,  and  at  the  middle 
of  the  lip  it  sends  a  branch  upwards,  to  supply  the  septum  of  the  nose  and 
the  mucous  membrane. 

The  Lateralis  nasi  is  distributed  to  the  ala  and  septum  of  the  nose. 

The  Inosculations  of  the  facial  artery  are  very  numerous :  thus,  it  anas- 
tomoses with  the  sublingual  branch  of  the  lingual,  with  the  ascending 
pharyngeal  and  posterior  palatine  arteries,  with  the  inferior  dental  as  it  es- 
capes from  the  mental  foramen,  infra-orbital  at  the  infra-orbital  foramen, 
transverse  facial  on  the  side  of  the  face,  and  at  the  angle  of  the  eye  with 
the  nasal  and  frontal  branches  of  the  ophthalmic  artery. 

The  facial  artery  is  subject  to  considerable  variety  in  its  extent :  it  not 
unfrequently  terminates  at  the  angle  of  the  nose  or  mouth,  and  is  rarely 
Mvmmetrical  on  both  sides  of  the  face. 


TRANSVERSALIS    FACIEI.  287 

4.  The  MASTOID  ARTERY  turns  downwards  from  its  origin,  to  be  dis- 
tributed to  the  sterno-mastoid  muscle,  and  to  the  lymphatic  glands  of  the 
neck ;  sometimes  it  is  replaced  by  two  small  branches. 

5.  The  OCCIPITAL  ARTERY,  smaller  than  the  anterior  branches,  passes 
backwards  beneath  the  posterior  belly  of  the  digastricus,  the  trachelo- 
mastoid  and  sterno-mastoid  muscles,  to  the  occipital  groove  in  the  mastoid 
portion  of  the  temporal  bone.     It  then  ascends  between  the  splenius  and 
complexus  muscles,  and  divides  into  two  branches  which  are  distributed 
upon  the  occiput,  anastomosing  with  the  opposite  occipital,  the  posterior 
auricular,  and  temporal  artery.     The  hypoglossal  nerve  curves  around  this 
artery  near  its  origin  from  the  external  carotid. 

Branches. — It  gives  off  only  two  branches  deserving  of  name,  the  infe- 
rior meningeal  and  princeps  cervicis. 

The  Inferior  meningeal  ascends  by  the  side  of  the  internal  jugular  vein, 
and  passes  through  the  foramen  lacerum  posterius,  to  be  distributed  to 
the  dura  mater. 

The  Arteria  princeps  cervicis  is  a  large  and  irregular  branch.  It  de- 
scends the  neck  between  the  complexus  and  semi-spinalis  colli,  and  inos- 
culates with  the  profunda  cervicis  of  the  subclavian.  This  branch  is  the 
means  of  establishing  a  very  important  collateral  circulation  between  the 
branches  of  the  carotid  and  subclavian,  after  the  ligature  of  the  common 
carotid  artery. 

6.  The  POSTERIOR  AURICULAR  ARTERY  arises  from  the  external  carotid, 
above  the  level  of  the  digastric  and  stylo-hyoid  muscles,  and  ascends  be- 
neath the  lower  border  of  the  parotid  gland,  and  behind  the  concha,  to  be 
distributed  by  two  branches  to  the  external  ear  and  side  of  the  head,  anas- 
tomosing with  the  occipital  and  temporal  arteries ;  some  of  its  branches 
pass  through  fissures  in  the  fibro-cartilage,  to  be  distributed  to  the  anterior 
surface  of  the  pinna.     The  anterior  auricular  arteries  are  branches  of  the 
temporal. 

Branches. — The  posterior  auricular  gives  off  but  one  named  branch,  the 
slylo-mastoid,  which  enters  the  stylo-mastoid  foramen  to  be  distributed  to 
the  aquaeductus  Fallopii  and  tympanum. 

7.  The  ASCENDING  PHARYNGEAL  ARTERY,  the  smallest  of  the  branches 
of  the  external  carotid,  arises  from  that  trunk  near  its  bifurcation,  and  as- 
cends between  the  internal  carotid  and  the  side  of  the  pharynx  to  the  base 
of  the  skull,  where  it  divides  into  two  branches ;  meningeal,  which  enters 
the  foramen  lacerum  posterius,  to  be  distributed  to  the  dura  mater ;  and 
pharyngeal.     It  supplies  the  pharynx,  tonsils,  and  Eustachian  tube. 

8.  The  PAROTIDEAN  ARTERIES  are  four  or  five  large  branches  which  are 
given  off  from  the  external  carotid  whilst  that  vessel  is  situated  in  the  pa- 
rotid gland.     They  are  distributed  to  the  structure  of  the  gland,  their  ter- 
minal branches  reaching  the  integument  and  the  side  of  the  face. 

9.  The  TRANSVERSALIS  FACIEI  arises  from  tha  external  carotid,  whilst 
that  trunk  is  lodged  within  the  parotid  gland ;  it  crosses  the  massetei 
muscle,  lying  parallel  with  and  a  little  above  Stenon's  duct ;  and  is  dis- 
tributed to  the  temporo-maxillary  articulation,  and  to  the  muscles  and  in 


288  INTERNAL    MAXILLARY    ARTERY. 

tegument  of  the  side  of  the  face,  inosculating  with  the  infra-orbital  and 
facial  artery.     This  artery  is  not  unfrequently  a  branch  of  the  temporal. 

10.  The  TEMPORAL  ARTERY  is  one  of  the  two  terminal  branches  of  the 
external  carotid.     It  ascends  over  the  root  of  the  zygoma;  and,  at  about 
an  inch  and  a  half  above  the  zygomatic  arch,  divides  into  an  anterior  and 
a  posterior  temporal  branch.     The  anterior  temporal  is  distributed  over 
the  front  of  the  temple  and  arch  of  the  skull,  and  anastomoses  with  the 
opposite  anterior  temporal,  and  with  the  supra-orbital  and  frontal  artery. 
The  posterior  temporal  curves  upwards  and  backwards,  and  inosculates 
with  its  fellow  of  the  opposite  side,  with  the  posterior  auricular  and  occi- 
pital artery. 

The  trunk  of  the  temporal  artery  is  covered  in  by  the  parotid  gland  and 
by  the  attrahens  aurem  muscle,  and  rests  on  the  temporal  fascia. 

Brandies. — Orbitar, 

Anterior  auricular, 
Middle  temporal. 

The  Orbitar  artery  is  a  small  branch,  not  always  present,  which  passes 
forward  immediately  above  the  zygoma,  between  the  two  layers  of  the 
temporal  fascia,  and  inosculates  beneath  the  orbicularis  palpebrarum  with 
the  palpebral  arteries. 

The  interior  auricular  arteries  are  distributed  to  the  anterior  portion 
of  the  pinna. 

The  Middle  temporal  branch  passes  through  an  opening  in  the  temporal 
fascia  immediately  above  the  zygoma,  and  supplies  the  temporal  muscle 
inosculating  with  the  deep  temporal  arteries. 

11.  The  INTERNAL  MAXILLARY  ARTERY,  the  other  terminal  branch  of  the 
external  carotid,  has  next  to  be  examined. 

Dissection. — The  Internal  maxillary  artery  passes  inwards  behind  the 
neck  of  the  lower  jaw  to  the  deep  structures  in  the  face  ;  we  require, 
therefore,  to  remove  several  parts  for  the  purpose  of  seeing  it  completely. 
To  obtain  a  good  view  of  the  vessel,  the  zygoma  should  be  sawn  across 
in  front  of  the  external  ear,  and  the  malar  bone  near  the  orbit.  Turn 
down  the  zygomatic  arch  with  the  masseter  muscle.  In  doing  this,  a 
small  artery  and  nerve  will  be  seen  crossing  the  sigmoid  notch  of  the 
lower  jaw,  and  entering  the  masseter  muscle  (the  masseteric).  Cut  away 
the  tendon  of  the  temporal  muscle  from  its  insertion  into  the  coronoid 
process,  and  turn  it  upwards  towards  its  origin ;  some  vessels  will  be  seen 
entering  its  under  surface ;  these  are  the  deep  temporal.  Then  saw  the 
ramus  of  the  jaw  across  its  middle,  and  dislocate  it  from  its  articulation 
with  the  temporal  bone.  Be  careful  in  doing  this  to  carry  the  blade  of 
the  knife  close  to  the  bone,  lest  any  branches  of  nerves  should  be  injured. 
Next  raise  this  portion  of  bone,  and  with  it  the  external  pterygoid  muscle. 
The  artery,  together  with  the  deep  branches  of  the  inferior  maxillary  nerve, 
will  be  seen  lying  on  the  pterygoid  muscles.  These  are  to  be  carefully 
freed  from  fat  and  areolar  tissue,  and  then  examined. 

This  artery  commences  in  the  substance  of  the  parotid  gland,  opposite 
the  meatus  auditorius  externus ;  it  passes  in  the  first  instance  horizontally 
forward  behind  the  neck  of  the  lower  jaw ;  next,  curves  around  the  lowei 
border  of  the  external  pterygoid  muscle  near  its  origin,  and  ascends  ob- 
liquely forwards  upon  the  outer  side  of  that  muscle  ;  it  then  passes  between 


INTERNAL    MAXILLARY    ARTERY. 


289 


the  two  heads  of  the  external  pterygoid,  Fig.  147.* 

and  enters  the  pterygo-raaxillary  fossa. 
Occasionally  it  passes  between  the  two 
pterygoid  muscles,  without  appearing  on 
the  outer  surface  of  the  external  ptery- 
goid. In  consideration  of  its  course, 
this  artery  may  be  divided  into  three 
portions :  maxillary,  pterygoid,  and 
spheno-maxillary. 

Relations. — The  maxillary  portion  is 
situated  between  the  ramus  of  the  jaw 
and  the  internal  lateral  ligament,  lying 
parallel  with  the  auricular  nerve ;  the 
pterygoid  portion  between  the  external 
pterygoid  muscle,  and  the  masseter  and 
temporal  muscle.  The  pterygo-maxillary  portion  lies  between  the  two 
heads  of  the  external  pterygoid  muscle,  and,  in  the  spheno-maxillary  fossa, 
is  in  relation  with  Meckel's  ganglion. 


Maxillary  Portion. 
Tympanic, 
Inferior  dental, 
Arteria  meningea  media, 
Arteria  meningea  parva. 


Branches. 


Pterygoid  Portion. 
Deep  temporal  branches, 
External  pterygoid, 
Internal  pterygoid, 
Masseteric, 
Buccal. 


Pterygo-maxillary  Portion. 
Superior  dental, 
Infra-orbital, 
Pterygo-palatine, 
Spheno-palatine, 
Posterior  palatine, 
Vidian. 

The  Tympanic  branch  is  small,  and  not  likely  to  be  seen  in  an  ordinary 
dissection ;  it  is  distributed  to  the  temporo-maxillary  articulation  and 
meatus,  and  passes  into  the  tympanum  through  the  fissura  Glaseri. 

The  Inferior  dental  descends  to  the  dental  foramen,  and  enters  the 
canal  of  the  lower  jaw  in  company  with  the  dental  nerve.  Opposite  the 
bicuspid  teeth  it  divides  into  two  branches,  one  of  which  is  continued  on- 
wards within  the  bone  as  far  as  the  symphisis,  to  supply  the  incisor  teeth, 

*  1.  The  external  carotid  artery.  2.  The  trunk  of  the  transverse  facial  artery.  3,  4. 
The  two  terminal  branches  of  the  external  carotid.  3.  The  temporal  artery ;  and  4. 
The  internal  rhaxillary,  the  first  or  maxillary  portion  of  its  course;  the  limit  of  this  por- 
tion is  marked  by  an  arrow.  5.  The  second,  or  pterygoid  portion,  of  the  artery;  me 
limits  are  bounded  by  the  arrows.  6.  The  third  or  ptery go-maxillary  portion.  The 
branches  of  the  maxillary  portion  are,  7.  A  tympanic  branch.  8.  The  arteria  meningea 
magna.  9.  The  arteria  meningea  parva.  10.  The  inferior  dental  artery.  The  branches 
of  the  second  portion  are  wholly  muscular,  the  ascending  ones  being  distributed  to  tn» 
temporal,  and  the  descending  to  the  four  other  muscles  of  the  inter-maxillary  region, 
viz.  the  two  pterygoids,  the  masseter  and  buccinator.  The  branches  of  the  pterygo 
maxillary  portion  of  the  artery  are,  11.  The  superior  dental  artery.  12.  The  infra-or- 
bital artery.  13.  The  posterior  palatine.  14.  The  spheno-palatine  or  nasal.  15.  Tha 
pterygo-palatine.  16.  The  Vidian.  *  The  remarkable  bend  which  the  third  portion 
of  the  artery  makes  as  it  turns  inwards  to  enter  the  pterygo-'.naxillary  fossa. 

25  T 


290  INTERNAL    MAXILLARY    ARTERY. 

•while  the  other  escapes  with  the  nerve  at  the  mental  foramen,  and  anasto- 
moses with  the  inferior  labial  and  submental  branch  of  the  facial.  It  sup- 
plies the  teeth  of  the  lower  jaw,  sending  small  branches  along  the  canals 
in  their  roots. 

The  Jlrteria  meningea  media  ascends  behind  the  temporo-maxillary  ar- 
ticulation to  the  foramen  spinosum  in  the  spinous  process  of  the  sphenoid 
bone,  and  entering  the  cranium,  divides  into  an  anterior  and  a  posterior 
branch.  The  anterior  branch  crosses  the  great  ala  of  the  sphenoid  to  the 
groove  or  canal  in  the  anterior  inferior  angle  of  the  parietal  bone,  and  di- 
vides into  branches,  which  ramify  upon  the  external  surface  of  the  dura 
mater,  and  anastomose  with  corresponding  branches  from  the  opposite 
side.  The  posterior  branch  crosses  the  squamous  portion  of  the  temporal 
oone,  to  the  posterior  part  of  the  dura  mater  and  cranium.  The  branches 
of  the  arteria  meningea  media  are  distributed  chiefly  to  the  bones  of  the 
skull ;  in  the  middle  fossa  this  artery  sends  a  small  branch  through  the 
hiatus  Fallopii  to  the  facial  nerve. 

The  Meningea  parva  is  a  small  branch  which  ascends  to  the  foramen 
ovale,  and  passes  into  the  skull  to  be  distributed  to  the  Casserian  ganglion 
and  dura  mater.  It  gives  off  a  twig  to  the  nasal  fossae  and  soft  palate. 

The  Muscular  branches  are  distributed,  as  their  names  imply,  to  the  five 
muscles  of  the  maxillary  region ;  the  temporal  branches  (temporales  pro- 
fundae)  are  two  in  number. 

The  Superior  dental  artery  is  given  off  from  the  internal  maxillary,  just 
as  that  vessel  is  about  to  make  its  turn  inwards  to  reach  the  spheno-max- 
illary  fossa.  It  descends  upon  the  tuberosity  of  the  superior  maxillary 
bone,  and  sends  its  branches  through  several  small  foramina  to  supply  the 
posterior  teeth  of  the  upper  ja\v,  and  the  antrum.  The  terminal  branches 
are  continued  forwards  upon  the  alveolar  process,  to  be  distributed  to  the 
gums  and  to  the  sockets  of  the  teeth. 

The  Infra-orbital  would  appear,  from  its  size,  to  be  the  proper  con- 
tinuation of  the  artery.  It  runs  along  the  infra-orbital  canal  with  the 
superior  maxillary  nerve,  sending  branches  into  the  orbit  and  downwards, 
through  canals  in  the  bone,  to  supply  the  mucous  lining  of  the  antrum 
and  the  teeth  of  the  upper  jaw,  and  it  emerges  on  the  face  at  the  infra- 
orbital  foramen.  The  branch  which  supplies  the  incisor  teeth  is  the  ante- 
rior dental  artery ;  on  the  face  the  infra-orbital  inosculates  with  the  facial 
and  transverse  facial  arteries. 

The  Pterygo-palatine  is  a  small  branch  which  passes  through  the 
pterygo-palatine  canal,  and  supplies  the  upper  part  of  the  pharynx  and 
Eustachian  tube. 

The  Spheno-palatine,  or  nasal,  enters  the  superior  meatus  of  the  nose 
through  the  spheno-palatine  foramen,  in  company  with  the  nasal  branches 
of  Meckel's  ganglion,  and  divides  into  two  branches ;  one  of  which  is 
distributed  in  the  mucous  membrane  of  the  septum,  while  the  other  sup- 
plies the  mucous  membrane  of  the  lateral  wall  of  the  nares,  together  with 
the  sphenoid  and  ethmoid  cells. 

T«e  Posterior  palatine  artery  descends  along  the  posterior  palatine 
canal,  in  company  witn  the  posterior  palatine  branches  of  Meckel's  gan- 
glion, to  the  posterior  palatine  foramen  ;  it  then  curves  forward,  lying  in 
a  groove  upon  the  bone,  and  is  distributed  to  the  palate.  While  in  the 
posterior  palatine  canal  it  sends  a  branch  backwards,  through  the  small 
posterior  palatine  foramen,  to  supply  the  soft  palate,  arid  anteriorly  it  dis- 


INTERNAL    CAROTID    ARTERY. 


291 


tributes  a  branch  to  the  anterior  palatine  canal,  which  reaches  the  naies, 
and  inosculates  with  the  branches  of  the  spheno-palatine  artery. 

The  Vidian  branch  passes  backwards  along  the  pterygoid  canal,  and  is 
distributed  to  the  sheath  of  the  Vidian  nerve,  and  to  the  Eustachian  tube. 

INTERNAL  CAROTID  ARTERY. 

The  internal  carotid  artery  curves  slightly  outwards  from  the  bifurcation 
of  the  common  carotid,  and  then  ascends  nearly  perpendicularly  through 
the  maxillo-pharyngeal  space*  to  the  carotid  foramen  in  the  petrous  bone. 
It  next  passes  inwards,  along  the  carotid  canal,  forwards  by  the  side  of 
the  sella  turcica,  and  upwards  by  the  anterior  clinoid  process,  where  it 
pierces  the  dura  mater,  and  divides  into  three  terminal  branches.  The 
course  of  this  artery  is  remarkable  for  the  number  of  angular  curves  which 
it  forms ;  one  or  two  of  these  flexures  are  sometimes  seen  in  the  cervical 
portion  of  the  vessel,  near  the  base  of  the  skull ;  and  by  the  side  of  the 
sella  turcica  it  resembles  the  italic  letter  s,  placed  horizontally. 

Relations.  —  In  consideration  of  its  connexions,  the  artery  is  divisible 
into  a  cervical,  petrous,  cavernous,  and  cerebral  portion.  The  Cervical 
portion  is  in  relation  posteriorly  with  the  rectus  anticus  major,  sympathetic 
nerve,  pharyngeal  and  laryngeal  nerves,  which  cross  behind  it,  and  near 
the  carotid  foramen  with  the  glosso-pharyngeal,  pneumogastric,  and  hypo- 
glossal  nerves,  and  partially  with  the  internal  jugular  vein.  Internally  it 
is  in  relation  with  the  side  of  the  pharynx,  the  tonsil,  and  the  ascending 
pharyngeal  artery.  Externally  with  the  internal  jugular  vein,  glosso- 
pharyngeal,  pneumogastric,  and  hypo-glossal  nerves;  and  in  front  with 
the  stylo-glossus,  and  stylo-pharyngeus  muscle,  glosso-pharyngeal  nerve, 
and  parotid  gland. 

Plan  of  the  Relations  of  the  Cervical  Portion  of  the  Internal  Carotid 

Artery. 

In  Front. 
Parotid  gland, 
Stylo-glossus  muscle, 
Stylo-pharyngeus  muscle, 
Glosso-pharyngeal  nerve. 


Internally. 

Pharynx, 
Tonsil, 
Ascending  pharyn- 
geal artery. 

Internal  Carotid 
Artery. 

Externally. 

Jugular  vein, 
Glosso-pharyngeal, 
Pneumogastric, 
Hypo-glossal  nerve. 

Behind. 

Superior  cervical  ganglion, 
Pneumogastric  nerve, 
Glosso-pharyngeal  nerve, 
Pharyngeal  nerve, 
Superior  laryngeal  nerve, 
Sympathetic  nerve, 
Rectus  anticus  major. 


The  Petrous  portion  is  separated  from  the  bony  wall  of  the  carotin 
canal  by  a  lining  of  dura  mater ;  it  is  in  relation  with  the  carotid  plexus, 
and  is  covered  in  by  the  Casserian  ganglion. 

•For  the  boundaries  of  this  space  see  page  188. 


292  OPHTHALMIC    ARTERY. 

The  Cavernous  portion  is  situated  in  the  inner  wall  of  the  cavernous 
sinus,  and  is  in  relation  by  its  outer  side  with  the  lining  membrane  of  the 
sinus,  the  sixth  nerve,  and  the  ascending  branches  of  the  carotid  plexus. 
The  third,  fourth,  and  ophthalmic  nerves  are  placed  in  the  outer  wall  of 
the  cavernous  sinus,  and  are  separated  from  the  artery  by  the  lining  mem- 
brane of  the  sinus. 

The  Cerebral  portion  of  the  artery  is  enclosed  in  a  sheath  of  the  arach 
noid,  and  is  in  relation  with  the  optic  nerve.  At  its  point  of  division  it  i 
situated  in  the  fissure  of  Sylvius. 

Branches. — The  cervical  portion  of  the  internal  carotid  gives  off  no 
branches :  from  the  other  portions  are  derived  the  following : — 

Tympanic, 

Anterior  meningeal, 

Ophthalmic, 

Anterior  cerebral, 

Middle  cerebral, 

Posterior  communicating, 

Choroidean. 

The  Tympanic  is  a  small  branch  which  enters  the  tympanum  through  a 
minute  foramen  in  the  carotid  canal. 

The  Anterior  meningeal  is  distributed  to  the  dura  mater  and  Casserian 
ganglion. 

The  Ophthalmic  artery  arises  from  the  cerebral  portion  of  the  internal 
carotid,  and  enters  the  orbit  through  the  foramen  opticum,  immediately  to 
the  outer  side  of  the  optic  nerve.  It  then  crosses  the  optic  nerve  to  the 
inner  wall  of  the  orbit,  and  runs  along  the  lower  border  of  the  superior 
oblique  muscle,  to  the  inner  angle  of  the  eye,  where  it  divides  into  two 
terminal  branches,  the  frontal  and  nasal. 

Branches. — The  branches  of  the  ophthalmic  artery  may  be  arranged  into 
two  groups :  first,  those  distributed  to  the  orbit  and  surrounding  parts ; 
and,  secondly,  those  which  supply  the  muscles  and  globe  of  the  eye. 
They  are — 

First  Group.  Second  Group. 

Lachrymal,  Muscular, 

Supra-orbital,  Anterior  ciliary, 

Posterior  ethmoidal,  Ciliary  short  and  long, 

Anterior  ethmoidal,  Centralis  retina;. 

Palpebral, 

Frontal, 

Nasal. 

The  Lachrymal  is  the  first  branch  of  the  ophthalmic  artery,  and  is  usu 
ally  given  off  immediately  before  that  artery  enters  the  optic  foramen.  It 
follows  the  course  of  the  lachrymal  nerve,  along  the  upper  border  of  the 
oxternal  rectus  muscle,  and  is  distributed  to  the  lachrymal  gland.  The 
small  branches  which  escape  from  the  gland  supply  the  conjunctiva  and 
upper  eyelid.  The  lachrymal  artery  gives  off  a  malar  branch  which  passes 
through  the  malar  bone  into  the  temporal  fossa  and  inosculates  with  the 
deep  temporal  arteries,  while  some  of  its  branches  become  subcutaneous 
on  the  cheek,  and  anastomose  with  the  transverse  facial. 


OPHTHALMIC    ARTERY. 

The  Supra-orbital  artery  follows  the  course  of  the  frontal  nerve,  resting 
on  the  levator  palpebrse  muscle ;  it  passes  through  the  supra-orbital  fora- 
men, and  divides  into  a  superficial  and  deep  branch,  which  are  distributed 
to  the  muscles  and  integument  of  the  forehead,  and  to  the  pericranium. 
At  the  supra-orbital  foramen  it  sends  a  branch  inwards  to  the  diploe. 

The  Ethmoidal  arteries,  posterior  and  anterior,  pass  through  the  eth- 
moidal  foramina,  and  are  distributed  to  the  falx  cerebri  and  to  the 
ethmoidal  cells  and  nasal  fossoe.  The  latter  accompanies  the  nasal  nerve. 

The  Palpebral  arteries,  superior  and  inferior,  are  given  off'  from  the 
ophthalmic,  near  the  inner  angle  of  the  orbit;  they  encircle  the  eyelids, 
forming  a  superior  and  an  inferior  arch  near  the  borders  of  the  lids,  between 
the  orbicularis  palpebrarum  an dtarsal  cartilage.  At  the  outer  angle  of  the 
eyelids  the  superior  palpebral  inosculates  with  the  orbitar  branch  of  the 
temporal  artery.  The  inferior  palpebral  artery  sends  a  branch  to  the  nasal 
duct. 

The  Frontal  artery,  one  of  the  terminal  branches  of  the  ophthalmic, 
emerges  from  the  orbit  at  its  inner  angle,  and  ascends  along  the  middle 
of  the  forehead.  It  is  distributed  to  the  integument,  muscles,  and  peri- 
cranium. 

The  Nasal  artery,  the  other  terminal  branch  of  the  ophthalmic,  passes 
out  of  the  orbit  above  the  tendo  oculi,  and  divides  into  two  branches  ;  one 
of  which  inosculates  with  the  angular  artery,  while  the  other,  the  dorsalis 
nasi,  runs  along  the  ridge  of  the  nose,  and  is  distributed  to  the  integument 
of  that  organ.  The  nasal  artery  sends  a  small  branch  to  the  lachrymal 
sac. 

The  Muscular  branches,  usually  two  in  number,  superior  and  inferior, 
supply  the  muscles  of  the  orbit ;  and  upon  the  anterior  aspect  of  the  globe 
of  the  eye  give  off  the  anterior  ciliary  arteries,  which  pierce  the  sclerotic 
near  its  margin  of  connection  with  the  cornea,  and  are  distributed  to  the 
iris.  It  is  the  congestion  of  these  vessels  that  gives  rise  to  the  vascular 
zone  around  the  cornea  in  iritis. 

The  Ciliary  arteries  are  divisible  into  three  groups,  short,  long,  and 
anterior. 

The  Short  ciliary  are  very  numerous ;  they  pierce  the  sclerotic  around 
the  entrance  of  the  optic  nerve,  and  supply  the  choroid  coat  and  ciliary 
processes.  The  long  ciliary,  two  in  number,  pierce  the  sclerotic  on  oppo- 
site sides  of  the  globe  of  the  eye,  and  pass  forwards  between  it  and  the 
choroid  to  the  iris.  They  form  an  arterial  circle  around  the  circumference 
of  the  iris  by  inosculating  with  each  other,  and  from  this  circle  branches 
are  given  off  which  ramify  in  the  substance  of  the  iris,  and  form  a  second 
circle  around  the  pupil.  The  anterior  ciliary  are  branches  of  the  muscular 
arteries ;  they  terminate  in  the  great  arterial  circle  of  the  iris. 

The  Centralis  retina  artery  pierces  the  optic  nerve  obliquely,  and  passes 
forwards  in  the  centre  of  its  cylinder  to  the  retina,  where  it  divides  into 
branches,  which  ramify  in  the  inner  layer  of  that  membrane.  It  supplies 
the  retina,  hyaloid  membrane,  and  zonula  ciliaris ;  and,  by  means  of  a 
branch  sent  forwards  through  the  centre  of  the  vitreous  humour  in  a  tubular 
sheath  of  the  hyaloid  membrane,  the  capsule  of  the  lens. 

The  interior  cerebral  artery  passes  forwards  in  the  great  longitudma. 
fissure  between  the  two  hemispheres  of  the  brain ;  then  curves  backwards 
along  the  corpus  callosum  to  its  posterior  extremity.  It  gives  branches 
25* 


294  SUBCLAVIAN    ARTERY. 

to  the  olfactory  and  optic  nerves,  to  the  under  surface  of  the  anterior  lobes, 
the  third  ventricle,  the  corpus  callosum,  and  the  inner  surface  of  the 
hemispheres.  The  two  anterior  cerebral  arteries  are  connected  soon  after 
their  origin  by  a  short  anastomosing  trunk,  the  anterior  communicating 

artery. 

The  Middle  cerebral  artery,  larger  than  the  preceding,  passes  outwards 
along  the  fissure  of  Sylvius,  and  divides  into  three  principal  branches, 
which  supply  the  anterior  and  middle  lobes  of  the  brain,  and  the  island 
of  Reil.  Near  its  origin  it  gives  off  the  numerous  small  branches  which 
enter  the  substantia  perforata,  to  be  distributed  to  the  corpus  striatum. 

The  Posterior  Communicating  artery,  very  variable  in  size,  sometimes 
double,  and  sometimes  altogether  absent,  passes  backwards  and  inoscu- 
lates with  the  posterior  cerebral,  a  branch  of  the  basilar  artery.  Occa- 
sionally it  is  so  large  as  to  take  the  place  of  the  posterior  cerebral 
artery. 

The  Choroidean  is  a  small  branch  which  is  given  off  from  the  internal 
carotid,  near  the  origin  of  the  posterior  communicating  artery,  and  passes 
beneath  the  edge  of  the  middle  lobe  of  the  brain  to  enter  the  descending 
cornu  of  the  lateral  ventricle.  It  is  distributed  to  the  choroid  plexus,  and 
to  the  walls  of  the  middle  cornu. 


SUBCLAVIAN    ARTERY. 


The  Subclavian  artery,  on  the  right  side,  arises  from  the  arteria  mno- 
minata,  opposite  the  sterno-clavicular  articulation,  and  on  the  left,  from 
the  arch  of  the  aorta.  The  right  is  consequently  shorter  than  the  left,  and 
is  situated  nearer  the  anterior  wall  of  the  chest ;  it  is  also  somewhat  greater 
in  diameter,  from  being  a  branch  of  a  branch,  in  place  of  a  division  from 
the  main  trunk. 

The  course  of  the  subclavian  artery  is  divisible,  for  the  sake  of  precision 
and  surgical  observation,  into  three  portions.  The  first  portion  of  the 
right  and  left  arteries  differs  in  its  course  and  relations  in  correspondence 
with  the  dissimilarity  of  origin  of  the  respective  arteries.  The  other  two 
portions  are  precisely  alike  on  both  sides. 

The  first  portion,  on  the  right  side,  ascends  obliquely  outwards  to  the 
inner  border  of  the  scalenus  anticus.  On  the  left  side  it  ascends  perpen- 
dicularly to  the  inner  border  of  that  muscle.  The  second  portion  curves 
outwards  behind  the  scalenus  anticus  ;  and  the  third  portion  passes  down- 
wards and  outwards  beneath  the  clavicle,  to  the  lower  border  of  the  first 
rib,  where  it  becomes  the  axillary  artery. 

Relations. — The  first  portion,  on  the  right  side,  is  in  relation,  in  front. 
with  the  internal  jugular  and  subclavian  vein  at  their  point  of  junction, 
and  is  crossed  by  the  pneumogastric  nerve,  cardiac  nerves,  and  phrenic 
nerve.  Behind  and  beneath  it  is  invested  by  the  pleura,  is  crossed  by  the 
right  recurrent  laryngeal  nerve  and  vertebral  vein,  and  is  in  relation  with 
the  transverse  process  of  the  seventh  cervical  vertebra.  The  first  portion 
on  the  left  side  is  in  relation  in  front  with  the  pleura,  the  vena  innomi- 
nata,  the  pneumogastric  and  phrenic  nerves  (which  lie  parallel  to  it),  and 
the  left  carotid  artery.  To  its  inner  side  is  the  oesophagus ;  to  its  outer 
side  the  pleura;  and  behind,  the  thoracic  duct,  longus  colli,  and  vertebral 
rolumn 


SLBCLAVIAN    ARTERY RELATIONS. 


205 


Plan  of  the  Relations  of  the  First  Portion  of  the  Right  Subclavian  Artery 

In  Front. 

Internal  jugular  vein, 
Subclavian  vein, 
Pneumogastric  nerve, 
Cardiac  nerves, 
Phrenic  nerve. 


Right  Subclavian  Artery. 


Behind  and  Beneath. 

Pleura, 
Recurrent  laryngeal  nerve, 

Vertebral  vein, 
Transverse  process  of  the  7th  cervical  vertebra. 


Plan  of  the  Relations  of  the  First  Portion  of  the  Left  Subclavian  Artery. 

In  Front. 
Pleura, 

Vena  innominata, 
Pneumogastric  nerve, 
Phrenic  nerve, 
Left  carotid  artery. 


Inner  Side. 
CEsophagus. 


Left  Subclavian  Artery. 


Outer  Side. 
Pleura. 


Behind. 

Thoracic  duct, 
Longus  colli, 
Vertebral  column. 

The  Second  portion  is  situated  between  the  two  scaleni,  and  is  supported 
by  the  margin  of  the  first  rib.  The  scalenus  anticus  separates  it  from  the 
Subclavian  vein  and  phrenic  nerve.  Behind,  it  is  in  relation  with  the 
brachial  plexus. 

The  Third  portion  is  in  relation,  in  front,  with  the  Subclavian  vein  and 
subclavius  muscle  ;  behind,  with  the  brachial  plexus  and  scalenus  posti- 
cus ;  below  with  the  first  rib ;  and  above  with  the  supra-scapular  artery 
and  platysma. 

Plan  of  the  Relations  of  the  Third  Portion  of  the  Subclavian  Artery. 

Above. 

Supra-scapular  artery, 
Platysma  myoides. 


In  Front. 

Subclavian  vein, 
Subclavius. 


Subclavian  artery, 
Third  portion. 


Behind. 

Brachial  plexus, 
Scalenus  posticun 


Below. 
First  rib. 


296 


VERTEBRAL    AND    BASILAR    ARTERIES. 


Branches. — The  greater  part  of  the  branches  of  the  subclavian  are  given 
off  from  the  artery  before  it  arrives  at  the  margin  of  the  first  rib.  The 
profunda  cervicis  and  superior  intercostal  frequently  encroach  upon  the 
second  portion,  and  not  unfrequently  a  branch  or  branches  may  be  found 
proceeding  from  the  third  portion. 

The  primary  branches  are  five  in  number,  the  first  three  being  ascend- 
ing, and  the  remaining  two  descending :  they  are  the — 


Vertebral, 
Thyroid  axis, 

Profunda  cervicis, 
Superior  intercostal. 
Internal  mammary. 


f  Inferior  thyroid, 
I  Supra-scapular, 
I  Posterior  scapular, 
[  Superficial  cervicis. 


Fig.  148.* 


The  VERTEBRAL  ARTERY  is  the  first  and  the  largest  of  the  branches  of 
the  subclavian  artery ;  it  ascends  through  the  foramina  in  the  transverse 

processes  of  all  the  cervical  vertebra?,  ex- 
cepting the  last ;  then  winds  backwards 
around  the  articulating  process  of  the  atlas ; 
and,  piercing  the  dura  mater,  enters  the  skull 
through  the  foramen  magnum.  The  two  arte- 
ries unite  at  the  lower  border  of  the  pons 
Varolii,  to  form  the  basilar  artery.  In  the 
foramina  of  the  transverse  processes  of  the 
vertebrae  the  artery  lies  in  front  of  the  cer- 
vical nerves. 

Dr.  John  Davyf  has  observed  that,  when 
the  vertebral  arteries  differ  in  size,  the  left  is 
generally  the  larger:  thus  in  ninety-eight 
cases  he  found  the  left  vertebral  the  larger 
twenty-six  times,  and  the  right  only  eight. 
In  the  same  number  of  cases  he  found  a 
small  band  stretching  across  the  cylinder  of 
the  basilar  artery,  near  the  junction  of  the  two  vertebral  arteries,  seventeen 
times,  and  in  a  few  instances  a  small  communicating  trunk  between  the 
two  vertebral  arteries  previously  to  their  union.  I  have  several  times  seen 
this  communicating  branch,  and  have  a  preparation  now  before  me  in 
which  it  is  exhibited. 

The  BASILAR  ARTERY,  so  named  from  its  position  at  the  base  of  the 
brain,  runs  forwards  to  the  anterior  border  of  the  pons  Varolii,  where  it 
divides  into  four  ultimate  branches,  two  to  either  side. 

Branches.  —  The  branches  of  the  vertebral  and  basilar  arteries  are  the 
following  :— 

*The  branches  of  the  right  subclavian  artery.  1.  The  arteria  innominata.  2.  The 
right  carotid.  3.  The  first  portion  of  the  subclavian  artery.  4.  The  second  portion 
f).  The  third  portion.  6.  The  vertebral  artery.  .  7.  The  inferior  thyroid.  8.  The  thyroid 
axis.  9.  The  superficialis  cervicis.  10.  The  profunda  cervicis.  11.  The  posterior 
scapular  or  transversalis  colli.  12.  The  supra-scapular.  13.  The  internal  mammary 
arteiy.  1-1.  Tin-  superior  intercostal. 

•j  F-linbuigh  Medical  and  Surgical  Journal,  1839. 


BASILAR   ARTERY  297 

'  Lateral  spinal, 
Posterior  meningeal, 
Vertebral,    <{  Anterior  spinal,1 
Posterior  spinal, 
Inferior  cerebellar. 

f  Transverse, 

Basilar  ^    <  Superior  cerebellar, 
[  Posterior  cerebral. 

The  Lateral  spinal  branches  enter  the  intervertebral  foramina,  and  are 
distributed  to  the  spinal  cord  and  to  its  membranes.  Where  the  vertebral 
artery  curves  around  the  articular  process  of  the  atlas,  it  gives  off  several 
muscular  branches. 

The  Posterior  meningeal  are  one  or  two  small  branches  which  enter  the 
cranium  through  the  foramen  magnum,  to  be  distributed  to  the  dura  mater 
of  the  cerebellar  fossae,  and  to  the  falx  cerebelli.  One  branch,  described 
by  Soemmering,  passes  into  the  cranium  along  the  first  cervical  nerve. 

The  interior  spinal  is  a  small  branch  which  unites  with  its  fellow  of  the 
opposite  side,  on  the  front  of  the  medulla  oblongata.  The  artery  formed 
by  the  union  of  these  two  vessels,  descends  along  the  anterior  aspect  of 
the  spinal  cord,  to  which  it  distributes  branches. 

The  Posterior  spinal  winds  around  the  medulla  oblongata  to  the  poste- 
rior aspect  of  the  cord,  and  descends  on  either  side,  communicating  very 
freely  with  the  spinal  branches  of  the  intercostal  and  lumbar  arteries. 
Near  its  commencement  it  sends  a  branch  upwards  to  the  four  ventricle. 

The  Inferior  cerebellar  arteries  wind  around  the  upper  part  of  the  me- 
dulla oblongata  to  the  under  surface  of  the  cerebellum,  to  which  they  are 
distributed.  They  pass  between  the  filaments  of  origin  of  the  hypo- 
glossal  nerve  in  their  course,  and  anastomose  with  the  superior  cerebellar 
arteries. 

The  Transverse  branches  of  the  basilar  artery  supply  the  pons  Varolii, 
and  adjacent  parts  of  the  brain.  One  of  these  branches,  larger  than  the 
rest,  passes  along  the  crus  cerebelli,  to  be  distributed  to  the  anterior  bor- 
der of  the  cerebellum.  This  may  be  called  the  middle  cerebellar  artery. 

The  Superior  cerebellar  arteries,  two  of  the  terminal  branches  of  the 
basilar,  wind  around  the  crus  cerebri  on  each  side,  lying  in  relation  with 
the  fourth  nerve,  and  are  distributed  to  the  upper  surface  of  the  cerebellum, 
inosculating  with  the  inferior  cerebellar.  This  artery  gives  off  a  small 
branch,  which  accompanies  the  seventh  pair  of  nerves  into  the  meatus 
auditorius  internus. 

The  Posterior  cerebral  arteries,  the  other  two  terminal  branches  of  the 
basilar,  wind  around  the  crus  cerebri  at  each  side,  and  are  distributed  to 
the  posterior  lobes  of  the  cerebrum.  They  are  separated  from  the  supe- 
rior cerebellar  arteries,  near  their  origin,  by  the  third  pair  of  nerves,  and  are 
in  close  relation  with  the  fourth  pair,  in  their  course  around  the  crura 
cerebri.  Anteriorly,  near  their  origin,  they  give  off  a  tuft  of  small  vessels, 
which  enter  the  locus  perforatus,  and  they  receive  the  posterior  communi- 
cating arteries  from  the  internal  carotid.  They  also  send  a  branch  to  the 
velum  interpositum  and  plexus  choroides. 

The  communications  established  between  the  anterior  cerebral  arteries 
in  front,  and  the  internal  carotids  and  posterior  cerebral  arteries  behind, 
by  the  communicating  arteries,  constitute  the  circle  of  Willis.  This 


IDS 


SUPRA-SCAPULAR    ARTERY. 


remarkable  communication  at  the  base  of  the  brain  is  formed  by  the  ante- 
rior communicating  branch,  anterior  cerebrals,  and  internal  carotid  arteries, 


Fig.  14  9» 


in  front,  and  by  the  posterior  communicating,  posterior  cerebrals,  and 
basilar  artery,  behind. 

The  THYROID  AXIS  is  a  short  trunk,  which  divides  almost  immediately 
after  its  origin  into  four  branches,  some  of  which  are  occasionally  branches 
of  the  subclavian  artery  itself. 

The  INFERIOR  THYROID  ARTERY  ascends  obliquely  in  a  serpentine  course 
behind  the  sheath  of  the  carotid  vessels,  to  the  inferior  part  of  the  thyroid 
gland,  to  which  it  is  distributed ;  it  sends  branches  also  to  the  trachea, 
lower  part  of  the  larynx,  and  oesophagus.  It  is  in  relation  with  the  middle 
cervical  ganglion  of  the  sympathetic,  which  lies  in  front  of  it. 

The  SUPRA-SCAPULAR  ARTERY  (transversalis  humeri)  passes  obliquely 
outwards  behind  the  clavicle,  and  over  the  ligament  of  the  supra-scapular 
notch,  to  the  supra-spinatus  fossa.  It  crosses  in  its  course  the  scalenus 
anticus  muscle,  phrenic  nerve,  and  subclavian  artery,  is  distributed  to  the 

*  The  circle  of  Willis.  The  arteries  have  references  only  on  one  side,  on  account  of 
their  symmetrical  distribution.  1.  The  vertebral  arteries.  2.  The  two  anterior  spinal 
branches  uniting  to  form  a  single  vessel.  3.  One  of  the  posterior  spinal  arteries.  4.  The 
posterior  meningeal.  5.  The  inferior  cerebellar.  6.  The  basilar  artery  giving  off  its 
transverse  branches  to  either  side.  7.  The  superior  cerebellar  artery.  8.  The  posterior 
cerebral.  9.  The  posterior  communicating  branch  of  the  internal  carotid.  10.  The  in- 
ternal carotid  artery,  showing  the  curvatures  it  makes  within  the  skull.  11.  The  oph- 
thalmic artery  divided  across.  12.  The  middle  cerebral  artery.  13.  The  anterior  cere- 
bral arteries  connected  by,  14.  The  anterior  communicating  artery. 


INTERNAL    MAMMARY    ARTERY.  299 

muscles  on  the  dorsum  of  the  scapula,  and  inosculates  with  the  posterior 
scapular,  and  beneath  the  acromion  process  with  the  dorsal  branch  of  the 
subscapular  artery.  At  the  supra-scapular  notch  it  sends  a  large  branch  to 
the  trapezius  muscle.  The  supra-scapular  artery  is  not  unfrequently  a 
branch  of  the  subclavian. 

The  POSTERIOR  SCAPULAR  ARTERY  (transversalis  colli)  passes  trans- 
versely across  the  subclavian  triangle  at  the  root  of  the  neck,  to  the  supe- 
rior angle  of  the  scapula.  It  then  descends  along  the  posterior  border  of 
that  bone  to  its  inferior  angle,  where  it  inosculates  with  the  subscapular 
artery,  a  branch  of  the  axillary.  In  its  course  across  the  neck  it  passes  in 
front  of  the  scalenus  anticus,  and  across  the  brachial  plexus ;  in  the  rest 
of  its  course  it  is  covered  in  by  the  trapezius,  levator  anguli  scapulae, 
rhomboideus  minor,  and  rhomboideus  major  muscles.  Sometimes  it  passes 
behind  the  scalenus  anticus,  and  between  the  nerves,  which  constitute  the 
brachial  plexus.  This  artery,  which  is  very  irregular  in  its  origin,  pro- 
ceeds more  frequently  from  the  third  portion  of  the  subclavian  artery  than 
from  the  first. 

The  posterior  scapular  gives  branches  to  the  neck,  and  opposite  the 
angle  of  the  scapula  inosculates  with  the  profunda  cervicis.  It  supplies 
the  muscles  along  the  posterior  border  of  the  scapula,  and  establishes  an 
important  anastomotic  communication  between  the  branches  of  the  exter- 
nal carotid,  subclavian,  and  axillary  arteries. 

The  SUPERFICTALIS  CERVICIS  ARTERY  (cervicalis  anterior)  is  a  small 
vessel,  which  ascends  upon  the  anterior  tubercles  of  the  transverse  pro- 
cesses of  the  cervical  vertebrae,  lying  in  the  groove  between  the  scalenus 
anticus  and  rectus  anticus  major.  It  is  distributed  to  the  deep  muscles 
and  glands  of  the  neck,  and  sends  branches  through  the  intervertebral 
foramina  to  supply  the  spinal  cord  and  its  membranes. 

The  PROFUNDA  CERVICIS  (cervicalis  posterior)  passes  backwards  between 
the  transverse  processes  of  the  seventh  cervical  and  first  dorsal  vertebrae, 
and  then  ascends  the  back  part  of  the  neck,  between  the  complexus  and 
semi-spinalis  colli  muscles.  It  inosculates  above  with  the  princeps  cervicis 
of  the  occipital  artery,  and  below,  by  a  descending  branch,  with  the  pos- 
terior scapular. 

The  SUPERIOR  INTERCOSTAL  ARTERY  descends  behind  the  pleura  upon 
the  necks  of  the  first  two  ribs,  and  inosculates  with  the  first  aortic  inter- 
costal. It  gives  off  two  branches  which  supply  the  first  two  intercostal 
spaces. 

The  INTERNAL  MAMMARY  ARTERY  descends  by  the  side  of  the  sternum, 
resting  against  the  costal  cartilages,  to  the  diaphragm ;  it  then  pierces  the 
anterior  fibres  of  the  diaphragm,  and  enters  the  sheath  of  the  rectus,  where 
it  inosculates  with  the  epigastric  artery,  a  branch  of  the  external  iliac.  In 
the  upper  part  of  its  course  it  is  crossed  by  the  phrenic  nerve,  and  lower 
down  lies  between  the  triangularis  sterni  and  the  internal  intercos*aJ 
muscles. 

The  Branches  of  the  internal  mammary  are, — 

Anterior  intercostal,  Mediastinal, 

Mammary,  Pericardiac, 

Comes  neivi  phrenic!,  Musculo-phrenic. 


300  AXILLARY    ARTERY. 

The  ^/Interior  intercostals  supply  the  intercostal  muscles  of  the  front  of 
the  chest,  and  inosculate  with  the  aortic  intercostal  arteries.  Each  of  the 
first  three  anterior  intercostals  gives  off  a  large  branch  to  the  mammary 
gland,  which  anastomoses  freely  with  the  thoracic  branches  of  the  axillary 
artery ;  the  corresponding  branches  from  the  remaining  intercostals  supply 
the  integument  and  pectoralis  major  muscle.  There  are  usually  two  an- 
terior intercostal  arteries  in  each  space. 

The  Comes  nervi  phrenici  is  a  long  and  slender  branch  which  accom- 
panies the  phrenic  nerve. 

The  mediastinal  and  pericardiac  branches  are  small  vessels  distributed 
to  the  anterior  mediastinum,  the  thymus  gland,  and  pericardium. 

The  Musculo-phrenic  artery  winds  along  the  attachment  of  the  diaphragm 
to  the  ribs,  supplying  that  muscle,  and  sending  branches  to  the  inferior 
intercostal  spaces.  "  The  mammary  arteries,"  says  Dr.  Harrison,  "  are 
remarkable  for  the  number  of  their  inosculations,  and  for  the  distant  parts 
of  the  arterial  system  which  they  serve  to  connect.  They  anastomose  with 
each  other,  and  their  inosculations,  with  the  thoracic  aorta,  encircle  the 
thorax.  On  the  parietes  of  this  cavity  their  branches  connect  the  axillary 
and  subclavian  arteries ;  on  the  diaphragm  they  form  a  link  in  the  chain 
of  inosculations  between  the  subclavian  artery  and  abdominal  aorta,  and 
in  the  parietes  of  the  abdomen  they  form  an  anastomosis  most  remarkable 
for  the  distance  between  those  vessels  which  it  serves  to  connect ;  namely, 
the  arteries  of  the  superior  and  inferior  extremities." 

Varieties  of  the  subclavian  Arteries. — Varieties  in  these  arteries  are  rare ; 
that  which  most  frequently  occurs  is  the  origin  of  the  right  subclavian, 
from  the  left  extremity  of  the  arch  of  the  aorta,  below  the  left  subclavian 
artery.  The  vessel,  in  this  case,  curves  behind  the  oesophagus  and  right 
carotid  artery,  and  sometimes  between  the  O3sophagus  and  trachea,  to  the 
upper  border  of  the  first  rib  on  the  right  side  of  the  chest,  where  it  assumes 
its  ordinary  course.  In  a  case*  of  subclavian  aneurism  on  the  right  side, 
above  the  clavicle,  which  happened  during  the  summer  of  1839,  Mr.  Lis- 
ton  proceeded  to  perform  the  operation  of  tying  the  carotid  and  subclavian 
arteries  at  their  point  of  division  from  the  innominata.  Upon  reaching 
the  spot  where  the  bifurcation  should  have  existed,  he  found  that  there 
was  no  subclavian  artery.  With  the  admirable  self-possession  which  dis- 
tinguishes this  eminent  surgeon  in  all  cases  of  emergency,  he  continued 
his  dissection  more  deeply,  towards  the  vertebral  column,  and  succeeded 
in  securing  the  artery.  It  was  ascertained  after  death,  that  the  arteria 
innominata  was  extremely  short,  and  that  the  subclavian  was  given  off 
within  the  chest  from  the  posterior  aspect  of  its  trunk,  and  pursued  a  deep 
course  to  the  upper  margin  of  the  first  rib.  In  a  preparation  which  was 
shown  to  me  in  Heidelberg  some  years  since  by  Professor  Tiedemann, 
the  right  subclavian  artery  arose  from  the  thoracic  aorta,  as  low  down  as 
the  fourth  dorsal  vertebra,  and  ascended  from  that  point  to  the  border  of 
the  first  rib.  Varieties  in  the  branches  of  the  subclavian  are  not  unfre- 
quenc ;  the  most  interesting  is  the  origin  of  the  left  vertebral  from  the  arch 
of  the  aorta,  of  which  I  possess  several  preparations. 

AXILLARY    ARTERY. 

The  axillary  artery  forms  a  gentle  curve  through  the  middle  of  the 

*  This  case  is  recorded  in  the  Lancet,  vol.  i.  1839-40,  pp.  37  and  419. 


AXILLARY    ARTERY — BRANCHES. 


301 


axillary  space  from  the  lower  border  of  the  first  rib  to  the  lower  border  of 
the  latissimus  dorsi,  where  it  becomes  the  brachial. 

Relations. — After  emerging  from  beneath  the  margin  of  the  costo-cora- 
coid  membrane,  it  is  in  relation  with  the  axillary  vein,  which  lies  at  first 
to  the  inner  side,  and  then  in  front  of  the  artery.  Near  the  middle  of  the 
axilla  it  is  embraced  by  the  two  heads  of  the  median  nerve,  and  is  covered 
in  by  the  pectoral  muscles.  Upon  the  inner  or  thoracic  side  it  is  in  rela- 
tion, first,  with  the  first  intercostal  muscle ;  it  next  rests  upon  the  first 
serration  of  the  serratus  magnus ;  and  is  then  separated  from  the  chest  by 
the  brachial  plexus  of  nerves.  By  its  outer  or  humeral  side  it  is  at  first 
separated  from  the  brachial  plexus  by  a  triangular  interval  of  areolar  tis- 
sue ;  it  next  rests  against  the  tendon  of  the  subscapularis  muscle ;  and 
thirdly,  upon  the  coraco-brachialis  muscle. 

The  relations  of  the  axillary  artery  may  be  thus  arranged : — 

In  Front.  Inner  or  Thoracic  Side.       Outer  or  Humeral  Side. 

First  intercostal  muscle,          Plexus  of  nerves, 
First  serration  of  serra-          Tendon   of  sub- 

tus  magnus,  scapularis, 

Plexus  of  nerves.  Coraco-brachialis. 


Pectoralis  major, 
Pectoralis  minor, 
Pectoralis  major. 


Branches. — The  branches  of  the  Axillary  artery  are  seven  in  number : — • 

Thoracica  acromialis,  Fig.  150.* 

Superior  thoracic, 

Inferior  thoracic, 

Thoracica  axillaris, 

Subscapular, 

Circumflex  anterior, 

Circumflex  posterior. 

The  thoracica  acromialis  and  superior 
thoracic  are  found  in  the  triangular  space 
above  the  pectoralis  minor.  The  inferior 
thoracic  and  thoracica  axillaris,  below  the 
pectoralis  minor.  And  the  three  remaining 
branches  below  the  lower  border  of  the  sub- 
scapularis. 

The  Thoracica  acromialis  is  a  short  trunk 
which  ascends  to  the  space  above  the  pec- 
toralis minor  muscle,  and  divides  into  three 
branches,  thoracic,  which  is  distributed  to 
the  pectoral  muscles  and  mammary  gland ; 
acromial,  which  passes  outwards  to  the 
acromion,  and  inosculates  with  branches  of 
the  supra-scapular  artery;  and  descending, 
which  follows  the  interspace  between  the 
deltoid  and  pectoralis  major  muscles,  and 
is  in  relation  with  the  cephalic  vein. 

*  The  axillary  and  brachial  artery,  with  their  branches.  1.  The  deltoid  muscle.  2 
The  biceps.  3.  The  tendinous  process  given  off  from  the  tendon  of  the  biceps,  to  .!ie 
deep  fascia  of  the  fore-arm.  It  is  this  process  which  separates  the  median  basilic  vein 
from  the  brachial  artery.  4.  The  outer  border  of  the  brachialis  anticus  muscle.  5.  Th«- 
supinator  longus.  6.  The  coraco-brachialis.  7.  Tlie  middle  portion  of  the  tricuin 

26 


302  VARIETIES    OF   THE    AXILLARY    ARTERY. 

The  Superior  thoracic  (short)  frequently  arises  by  a  common  trunk  with 
the  preceding;  it  runs  along  the  upper  border  of  the  pectoralis  minor, 
and  is  distributed  to  the  pectoral  muscles  and  mammary  gland,  inosculat 
ino-  with  the  intercostal  and  mammary  arteries. 

'The  Inferior  thoracic  (long  external  mammary)  descends  along  the 
lower  border  of  the  pectoralis  minor  to  the  side  of  the  chest.  It  is  distri- 
buted to  the  pectoralis  major  and  minor,  serratus  magnus,  and  subscapu- 
laris  muscle,  to  the  axillary  glands  and  mammary  gland;  inosculating 
with  the  superior  thoracic,  intercostal,  and  mammary  arteries. 

The  Thoracica  axillaris  is  a  small  branch  distributed  to  the  plexus  of 
nerves  and  glands  in  the  axilla.  It  is  frequently  derived  from  one  of  the 
other  thoracic  branches. 

The  Subscapular  artery,  the  largest  of  the  branches  of  the  axillary,  runs 
along  the  lower  border  of  the  subscapularis  muscle,  to  the  inferior  angle 
of  the  scapula,  where  it  inosculates  with  the  posterior  scapular,  a  branch 
of  the  subclavian.  It  supplies,  in  its  course,  the  muscles  on  the  under 
surface  and  inferior  border  of  the  scapula,  and  the  side  of  the  chest.  At 
about  an  inch  and  a  half  from  the  axillary,  it  gives  off  a  large  branch,  the 
dorsalis  scapulce,  which  passes  backwards  through  the  triangular  space 
bounded  by  the  teres  minor,  teres  major,  and  scapular  head  of  the  triceps, 
and  beneath  the  infra-spinatus  to  the  dorsum  of  the  scapula,  where  it  is 
distributed,  inosculating  with  the  supra-scapular  and  posterior  scapular 
arteries. 

The  Circumflex  arteries  wind  around  the  neck  of  the  humerus.  The 
anterior, very  small,  passes  beneath  the  coraco-brachialis  and  short  head 
of  the  biceps,  and  sends  a  branch  upwards  along  the  bicipital  groove  to 
supply  the  shoulder  joint. 

The  Posterior  circumflex,  of  larger  size,  passes  backwards  through  the 
quadrangular  space  bounded  by  the  teres  minor  and  major,  the  scapular 
head  of  the  triceps  and  the  humerus,  and  is  distributed  to  the  deltoid 
muscle  and  joint.  Sometimes  this  artery  is  a  branch  of  the  superior  pro- 
funda  of  the  brachial.  It  then  ascends  behind  the  tendon  of  the  teres 
major,  and  is  distributed  to  the  deltoid  without  passing  through  the  quad- 
rangular space.  The  posterior  circumflex  artery  sends  branches  to  the 
shoulder  joint. 

Varieties  of  tlie  Axillary  artery. — The  most  frequent  peculiarity  of  this 
kind  is  the  division  of  the  vessel  into  two  trunks  of  equal  size :  a  muscular 
trunk,  which  gives  off  some  of  the  ordinary  axillary  branches  and  supplies 
the  upper  arm,  and  a  continued  trunk,  which  represents  the  brachial  ar- 
tery. The  next  most  frequent  variety  is  the  high  division  of  the  ulnar 
which  passes  down  the  arm  by  the  side  of  the  brachial  artery,  and  superfi- 
cially to  the  muscles  proceeding  from  the  inner  condyle,  to  its  ordinary 
distribution  in  the  hand.  In  this  course  it  lies  immediately  beneath  the 

muscle.  8.  Its  inner  head.  9.  The  axillary  artery.  10.  The  brachial  artery ; — a  dark 
line  marks  the  limit  between  these  two  vessels.  11.  The  thoracica  acromialis  artery 
dividing  into  its  three  branches ;  the  number  rests  upon  the  coracoid  process.  12.  The 
superior  and  inferior  thoracic  arteries.  13.  The  serratus  magnus  muscle.  14.  The 
subscapular  artery.  The  posterior  circumflex  and  thoracica  axillaris  branches  are  seen 
in  the  figure  between  the  inferior  thoracic  and  subscapular.  Th3  anterior  circumflex 
is  observed,  between  the  two  heads  of  the  biceps,  crossing  the  :aeck  of  the  humerus. 
The  superior  profunda  artery.  16.  The  inferior  profunda.  17.  The  anastomotica 
mapna  inosculating  inferiorly  with  the  anterior  ulnar  recurrent.  18.  The  termination 
of  the  superior  profunda.  inosculating  with  the  radial  recurrent  in  the  interspace  be- 
tween the  brachialis  anticus  and  supinator  longus. 


BRACHIAL   ARTERY.  303 

deep  fascia  of  the  fore-arm,  and  may  be  seen  and  felt  pulsating  beneath 
the  integument.  The  high  division  of  the  radial  from  the  axillary  is  rare. 
In  one  instance,  I  saw  the  axillary  artery  divide  into  three  branches  of 
nearly  equal  size  which  passed  together  down  the  arm,  and  at  the  bend 
of  the  elbow  resolved  themselves  into  radial,  ulnar,  and  interosseous.  But 
the  most  interesting  variety,  both  in  a  physiological  and  surgical  sense,  is 
that  described  by  Dr.  Jones  Quain,  in  his  "  Elements  of  Anatomy."  "  I 
found  in  the  dissecting-room,  a  few  years  ago,  a  variety  not  hitherto  no- 
ticed ;  it  was  at  first  taken  for  the  ordinary  high  division  of  the  ulnar 
artery.  The  two  vessels  descended  from  the  point  of  division  at  the  bor- 
der of  the  axilla,  and  lay  parallel  with  one  another  in  their  course  through 
the  arm ;  but  instead  of  diverging,  as  is  usual,  at  the  bend  of  the  elbow, 
they  converged,  and  united  so  as  to  form  a  short  trunk  which  soon  divided 
again  into  the  radial  and  ulnar  arteries  in  the  regular  way."  In  a  subject, 
dissected  by  myself,  this  variety  existed  in  both  arms ;  and  I  have  seen 
several  instances  of  a  similar  kind. 

BRACHIAL    ARTERY. 

The  Brachial  artery  passes  down  the  inner  side  of  the  arm,  from,  the 
lower  border  of  the  latissimus  dorsi  to  the  bend  of  the  elbow,  where  it  di- 
vides into  the  radial  and  ulnar  arteries., 

Relations. — In  its  course  downwards,  it  rests  upon  the  coraco-brachialis 
muscle,  internal  head  of  the  triceps,  brachialis  anticus,  and  the  tendon  of 
the  biceps.  To  its  inner  side  is  the  ulnar  nerve ;  to  the  outer  side,  the 
coraco-brachialis  and  biceps  muscles ;  in  front  it  has  the  basilic  vein,  and 
is  crossed  by  the  median  nerve.  Its  relations,  within  its  sheath,  are  the 
venae  comites. 

Plan  of  the  Relations  of  the  Brachial  Artery. 

In  Front. 

Basilic  vein, 
Deep  fascia, 
Median  nerve. 


Inner  Side. 
Ulnar  nerve. 


Brachial  artery. 


Outer  Side. 
Coraco-brachialis, 
Biceps. 


Behind. 

Short  head  of  triceps, 
Coraco-brachial  is, 
Brachialis  anticus, 
Tendon  of  biceps. 

The  branches  of  the  brachial  artery  are,  the— 

Superior  profunda, 
Inferior  profunda, 
Anastomotica  magna, 
Muscular. 

The  Superior  profunda  arises  opposite  the  lower  border  of  the 
dorsi,  and  winds  around  the  humerus,  between  the  triceps  and  the  bone, 
fo  the  space  between  the  brachialis  anticus  and  supinator  longus,  where  it 


301 


RADIAL   ARTERY. 


Fig.  151  * 


inosculates  with  the  radial  recurrent  branch.  It 
accompanies  the  musculo-spiral  nerve.  In  its 
course  it  gives  off  the  posterior  articular  artery, 
which  descends  to  the  elbow  joint,  and  a  more 
superficial  branch  which  inosculates  with  the  in- 
terosseous  articular  artery. 

The  Inferior  profunda  arises  from  about  the 
middle  of  the  brachial  artery,  and  descends  to 
the  space  between  the  inner  condyle  and  olecra- 
non  in  company  with  the  ulnar  nerve,  where  it 
inosculates  with  the  posterior  ulnar  recurrent. 

The  Jinastomotica  magna  is  given  off  nearly 
at  right  angles  from  the  brachial,  at  about  two 
inches  above  the  joint.  It  passes  directly  inwards, 
and  divides  into  two  branches  which  inosculate 
with  the  anterior  and  posterior  ulnar  recurrent 
arteries  and  with  the  inferior  profunda. 

The  Muscular  branches  are  distributed  to  the 
muscles  in  the  course  of  the  artery,  viz.  to  the 
coraco-brachialis,  biceps,  deltoid,  brachialis  an- 
ticus  and  triceps. 

Varieties  of  the  Brachial  Artery. — The  most 
frequent  peculiarity  in  the  distribution  of  branches 
from  this  artery  is  the  high  division  of  the  radial, 
which  arises  generally  from  about  the  upper  third 
of  the  brachial  artery,  and  descends  to  its  normal 
position  at  the  bend  of  the  elbow.  The  ulnar 
artery  sometimes  arises  from  the  brachial  at 
about  two  inches  above  the  elbow,  and  pursues 
either  a  superficial  or  deep  course  to  the  wrist ; 

and,  in  more  than  one  instance,  I  have  seen  the  interosseous  artery  arise 
from  the  brachial  a  little  above  the  bend  of  the  elbow.  The  two  profunda 
arteries  occasionally  arise  by  a  common  trunk,  or  there  may  be  two  superior 
profundse. 

RADIAL    ARTERY. 

The  Radial  artery,  one  of  the  divisions  of  the  brachial,  appears,  from 
its  direction,  to  be  the  continuation  of  that  trunk.  It  runs  along  the  radial 
side  of  the  fore-arm,  from  the  bend  of  the  elbow  to  the  wrist ;  it  there 
turns  around  the  base  of  the  thumb,  beneath  its  extensor  tendons,  and 

•  The  arteries  of  the  fore-arm.     1.  The  lower  part  of  the  biceps  muscle.    2.  The  inner 
condyle  of  the  humerus  with  the  humeral  origin  of  the  pronator  radii  teres  and  flexor 
carpi  radialis  divided  across.     3.  The  deep  portion  of  the  pronator  radii  teres.     4.  The 
supinator  longus  muscle.     5.  The  flexor  longus  pollicis.    6.  The  pronator  quadratus.     7. 
The  flexor  profundus  digitorum.     8.  The  flexor  carpi  ulnaris.     9.  The  annular  ligament 
with  the  tendons  passing  beneath  it  into  the  palm  of  the  hand ;   the  figure  is  placed  on 
the  tendon  of  the  palmaris  longus  muscle,  divided  close  to  its  insertion.    10.  The  brachial 
rtery.     11.  The  anastomotica  magna  inosculating  superiorly  with  the  inferior  profunda, 
d  inferiorly  with  the  anterior  ulna  recurrent.     12.  The  radial  artery.     13.  The  radial 
recurrent  artery  inosculating  with  the  termination  of  the  superior  profunda.     14.  The 
superficialis  volae.     15.  The  ulnar  artery.     16.  Its  superficial  palmar  arch  giving  off  di- 
gitalI  branches  to  three  fingers  and  a  half.     17.  The  magna  pollicis  and  radialis  arteries. 
Ihe  posterior  ulnar  recurrent.     19.  The  anterior  interosseous  artery.    20.  The  poste- 
rior interosseons,  as  it  is  passing  through  »he  interosseous  membrane. 


RADIAL    ARTERY.  305 

passes  between  the  two  heads  of  the  first  dorsal  in^erosseous  muscle,  into 
the  palm  of  the  hand.     It  then  crosses  the  metacarpal  bones  to  the  ulnar 
side  of  the  hand,  forming  the  deep  palmar  arch,  and  terminates  by  inoscu 
lating  with  the  superficial  palmar  arch. 

In  the  upper  half  of  its  course,  the  radial  artery  is  situated  between  the 
supinator  longus  muscle,  by  which  it  is  overlapped  superiorly,  and  the 
pronator  radii  teres ;  in  the  lower  half,  between  the  tendons  of  the  supina- 
tor longus  and  flexor  carpi  radialis.  It  rests  in  its  course  downwards, 
upon  the  supinator  brevis,  pronator  radii  teres,  radial  origin  of  the  flexor 
sublimis,  flexor  longus  pollicis,  and  pronator  quadratus ;  and  is  covered 
in  by  the  integument  and  fasciae.  At  the  wrist  it  is  situated  in  contact 
with  the  dorsal  carpal  ligaments  and  beneath  the  extensor  tendons  of  the 
thumb  ;  and,  in  the  palm  of  the  hand,  beneath  the  flexor  tendons.  It  is 
accompanied  by  venae  comites  throughout  its  course,  and  by  its  middle 
third  is  in  close  relation  with  the  radial  nerve. 

Plan  of  the  Relations  of  the  Radial  Artery  in  the  Fore-am. 

In  Front. 
Deep  fascia, 
Supinator  longus. 


Inner  Side. 

Pronator  radii  teres, 
Flexor  carpi  radialis. 


Radial  artery. 


Outer  side. 

Supinator  longus, 
Radial    nerve   (middle 
third  of  its  course). 


Behind. 

Supinator  brevis, 
Pronator  radii  teres, 
Flexor  sublimis  digitorum, 
Flexor  longus  pollicis. 
Pronator  quadratus, 
Wrist  joint. 

The  Branches  of  the  radial  artery  may  be  arranged  into  three  groups, 
corresponding  with  the  three  regions,  the  fore-arm,  the  wrist,  and  the 
hand  ;  they  are — 

r,  (  Recurrent  radial, 

Fore-arm,       J  Musm}^ 

f  Superficial  volae, 

Carpalis  anterior, 
Wrist,  -j  Carpalis  posterior, 

Metacarpalis, 
[  Dorsales  pollicis. 

(Princeps  pollicis, 
Radialis  indicis, 
T  ,  ' 

Interossese, 
Perforantes. 

The  Recurrent  branch  is  given  off  immediately  below  the  elbow ;  it  as 
cends  in  the  space  between  the  supinator  longus  and  brachialis  anticus  to 
supply  the  joint,  and  inosculates  with  the  terminal  branches  of  the  superior 
profunda.     This  vessel  gives  off  numerous  muscular  branches. 

The  Muscular  branches  are  distributed  to  the  muscles  on  the  radial  side 
of  the  fore-arm. 

26*  u 


306  ULNAR    ARTERY. 

The  Superficialis  volte  is  given  off  from  the  radial  artery  while  at  the 
wrist.  It  passes  between  the  fibres  of  the  abductor  pollicis  muscle,  and 
inosculates  with  the  termination  of  the  ulnar  artery,  completing  the  super- 
ficial palmar  arch.  This  artery  is  very  variable  in  size,  being  sometimes 
as  large  as  the  continuation  of  the  radial,  and  at  other  times  a  mere  mus- 
cular ramusculus,  or  entirely  wanting ;  when  of  large  size  it  supplies  the 
palmar  side  of  the  thumb  and  the  radial  side  of  the  index  finger. 

The  Carpal  branches  are  intended  for  the  supply  of  the  wrist,  the  ante- 
rior carpal  in  front,  and  the  posterior,  the  larger  of  the  two,  behind.  The 
carpalis  posterior  crosses  the  carpus  transversely  to  the  ulnar  border  of  the 
hand,  where  it  inosculates  with  the  posterior  carpal  branch  of  the  ulnar 
artery.  Superiorly  it  sends  branches  which  inosculate  with  the  termination 
of  the  anterior  interosseous  artery ;  inferiorly  it  gives  off  posterior  inter  os- 
seous branches,  which  anastomose  with  the  perforating  branches  of  the 
deep  palmar  arch,  and  then  run  forward  upon  the  dorsal  interossei  mus- 
cles. 

The  Metacarpal  branch  runs  forward  on  the  second  dorsal  interosseous 
muscle,  and  inosculates  with  the  digital  branch  of  the  superficial  palmar 
arch,  which  supplies  the  adjoining  sides  of  the  index  and  middle  fingers. 
Sometimes  it  is  of  large  size,  and  the  true  continuation  of  the  radial  ar- 
tery. 

The  Dorsales  pollicis  are  two  small  branches  which  run  along  the  sides 
of  the  dorsal  aspect  of  the  thumb. 

The  Princeps  pollicis  descends  along  the  border  of  the  metacarpal  bone, 
between  the  abductor  indicis  and  adductor  pollicis  to  the  base  of  the  first 
phalanx,  where  it  divides  into  two  branches,  which  are  distributed  to  the 
two  sides  of  the  palmar  aspect  of  the  thumb. 

The  Radialis  indicis  is  also  situated  between  the  abductor  indicis  and 
the  adductor  pollicis,  and  runs  along  the  radial  side  of  the  index  finger, 
forming  its  collateral  artery.  This  vessel  is  frequently  a  branch  of  the 
princeps  pollicis. 

The  Interossea,  three  or  four  in  number,  are  branches  of  the  deep  pal- 
mar arch ;  they  pass  forward  upon  the  interossei  muscles,  and  inosculate 
with  the  digital  branches  of  the  superficial  arch,  opposite  the  heads  of  the 
metacarpal  bones. 

The  Per  for  antes  j  three  in  number,  pass  directly  backwards  between  the 
heads  of  the  dorsal  interossei  muscles,  and  inosculate  with  the  posterior 
interosseous  arteries. 

ULNAR    ARTERY. 

The  Ulnar  artery,  the  other  division  of  the  brachial  artery,  crosses  the 
arm  obliquely  to  the  commencement  of  its  middle  third  ;  it  then  runs  down 
the  ulnar  side  of  the  fore-arm  to  the  wrist,  crosses  the  annular  ligament, 
and  forms  the  superficial  palmar  arch,  which  terminates  by  inosculating 
with  the  superficialis  volae. 

Relations.  —  In  the  upper  or  oblique  portion  of  its  course,  it  lies  upon 
the  brachialis  anticus  and  flexor  profundus  digitorum  ;  and  is  covered  in 
by  the  superficial  layer  of  muscles  of  the  fore-arm  and  by  the  median  nerve. 
In  the  second  part  of  its  course,  it  is  placed  upon  the  flexor  profundus  and 
ponator  quadratus,  lying  between  the  flexor  carpi  ulnaris  and  flexor  sub- 
Jimis  digitorum.  While  crossing  the  annular  ligament  it  is  protected  from 
injury  by  a  strong  tendinous  arch,  thrown  over  it  from  the  pisiform  bone ; 


ULNAR  ARTERY — BRANCHES.  307 

and  in  the  palm  it  rests  upon  the  tendons  of  the  flexor  sublimis,  being 
covered  in  by  the  palmaris  brevis  muscle  and  palmar  fascia.  It  is  accom- 
panied in  its  course  by  the  vena?  comites,  and  is  in  relation  with  the  ulnar 
nerve  for  the  lower  two-thirds  of  its  extent. 

Plan  oftlie  Relations  of  the  Ulnar  Jlrtery. 

In  Front. 

Deep  fascia, 

Superficial  layer  of  muscles, 
Median  nerve. 

In  the  Hand. 

Tendinous  arch  from  the  pisiform  bone, 

Palmaris  brevis  muscle, 

Palmar  fascia. 


Inner  Side. 


Flexor  carpi  ulnaris, 
Ulnar  nerve  (lower 
two-thirds). 


Ulnar  artery. 


Outer  Side. 
Flexor  sublimis  digi- 


torum. 


Behind. 

Brachialis  anticus, 

Flexor  profundus  digitorum, 

Pronator  quadratus. 

In  the  Hand. 

Annular  ligament, 
Tendons  of  the  flexor  sublimis  digitorum. 

The  Branches  of  the  ulnar  artery  may  be  arranged,  like  those  of  the 
radial,  into  three  groups : — 

f  Anterior  ulnar  recurrent, 
Posterior  ulnar  recurrent, 

Fore-arm,  \  Interosseous      J  Anterior  interosseous, 
us>     j  Posterior  interosseous. 
[  Muscular. 

Wrist         \  Carpalis  anterior, 
\  Carpalis  posterior. 
Hand,  Digitales. 

The  ./Interior  ulnar  recurrent  arises  immediately  below  the  elbow,  and 
ascends  in  front  of  the  joint  between  the  pronator  radii  teres  and  brachialis 
anticus,  where  it  inosculates  with  the  anastomotica  magna  and  inferior 
profunda.  The  two  recurrent  arteries  frequently  arise  by  a  common 
trunk. 

The  Posterior  ulnar  recurrent,  larger  than  the  preceding,  arises  imme- 
diately below  the  elbow  joint,  and  passes  backwards  beneath  the  origins 
of  the  superficial  layer  of  muscles ;  it  then  ascends  between  the  two  heads 
of  the  flexor  carpi  ulnaris,  and  beneath  the  ulnar  nerve,  and  inosculates 
with  the  inferior  profunda  and  anastomotica  magna. 

The  Common  interosseous  artery  is  a  short  trunk  which  arises  from  the 
ulnar,  opposite  the  bicipital  tuberosity  of  the  radius.  It  divides  into  two 
branches,  the  anterior  and  posterior  interosseous  arteries. 


308  BRANCHES    OF   THE   THORACIC    AORTA. 

The  Anterior  interosseous  passes  down  the  fore-arm  upon  the  intercsse- 
ous  membrane,  between  the  flexor  profundus  digitorum  and  flexor  longus 
pollicis,  and  behind  the  pronator  quadratus.  In  the  latter  position  it 
pierces  the  interosseous  membrane,  and  descends  to  the  back  of  the  wrist, 
where  it  inosculates  with  the  posterior  carpal  branches  of  the  radial  and 
ulnar.  It  is  retained  in  connexion  with  the  interosseous  membrane  by 
means  of  a  thin  aponeurotic  arch. 

The  anterior  interosseous  artery  sends  a  branch  to  the  median  nerve, 
which  it  accompanies  into  the  hand.  The  median  artery  is  sometimes  of 
large  size,  and  occasionally  takes  the  place  of  the  superficial  palmar  arch. 

The  Posterior  interosseous  artery  passes  backwards  through  an  opening 
oetween  the  upper  part  of  the  interosseous  membrane  and  the  oblique 
ligament,  and  is  distributed  to  the  muscles  on  the  posterior  aspect  of  the 
fore-arm.  It  gives  off  a  recurrent  branch,  which  returns  upon  the  elbow 
between  the  anconeus,  extensor  carpi  ulnaris  and  supinator  brevis  muscles, 
and  anastomoses  with  the  posterior  terminal  branches  of  the  superior  pro- 
funda. 

The  Muscular  branches  supply  the  muscles  situated  along  the  ulnar 
border  of  the  fore-arm. 

The  Carpal  branches,  anterior  and  posterior,  are  distributed  to  the  an- 
terior and  posterior  aspects  of  the  wrist  joint,  where  they  inosculate  with 
corresponding  branches  of  the  radial  artery. ' 

The  Digital  branches  are  given  off  from  trie  superficial  palmar  arch,  and 
are  four  in  number.  The  first  and  smallest  is  distributed  to  the  ulnar  side 
of  the  little  finger.  The  other  three  are  short  trunks,  which  divide  be- 
tween the  heads  of  the  metacarpal  bones,  and  form  the  collateral  branch 
of  the  radial  side  of  the  little  finger,  the  collateral  branches  of  the  ring  and 
middle  fingers,  and  the  collateral  branch  of  the  ulnar  side  of  the  index 
finger. 

The  Superficial  palmar  arch  receives  the  termination  of  the  deep  palmar 
arch  from  between  the  abductor  minimi  digiti  and  flexor  brevis  minimi 
digiti  near  their  origins,  and  terminates  by  inosculating  with  the  superfi- 
cialis  volae  upon  the  ball  of  the  thumb.  The  communication  between  the 
superficial  and  deep  arch  is  generally  described  as  the  communicating 
branch  of  the  ulnar  artery. 

The  mode  of  distribution  of  the  arteries  to  the  hand  is  subject  to  fre- 
quent variety. 

BRANCHES  OF  THE  THORACIC  AORTA. 

Bronchial, 

CEsophageal, 

Intercostal. 

The  BRONCHIAL  ARTERIES  are  four  in  number,  and  vary  both  in  size 
and  origin.  They  are  distributed  to  the  bronchial  glands  and  tubes,  and 
send  branches  to  the  cesophagus,  pericardium,  and  left  auricle  of  the  heart. 
These  are  the  nutritious  vessels  of  the  lungs. 

The  CESOPHAGEAL  ARTERIES  are  numerous  small  branches ;  they  arise 
from  the  anterior  part  of  the  aorta,  are  distributed  to  the  oesophagus,  and 
establish  a  chain  of  anastomoses  along  that  tube  :  the  superior  inosculate 
with  the  bronchial  arteries,  and  with  oasophageal  branches  of  the  inferior 


BRANCHES    OF    THE    ABDOMINAL    AORTA.  309 

thyroid  arteries ;  and  the  inferior  with  similar  branches  of  the  phrenic  and 
gastric  arteries. 

The  INTERCOSTAL,  or  posterior  intercostal  arteries,  arise  from  the  poste 
rior  part  of  the  aorta ;  they  are  nine  in  number  on  each  side,  the  two  su 
perior  spaces  being  supplied  by  the  superior  intercostal  artery,  a  branch 
of  the  subclavian.  The  right  intercostals  are  longer  than  the  left,  on  ac- 
count of  the  position  of  the  aorta.  They  ascend  somewhat  obliquely  from 
their  origin,  and  cross  the  vertebral  column  behind  the  thoracic  duct,  vena 
azygos  major,  and  sympathetic  nerve,  to  the  intercostal  spaces,  the  left 
pacing  beneath  the  superior  intercostal  vein,  the  vena  azygos  minor  and 
sympathetic.  In  the  intercostal  spaces,  or  rather,  upon  the  external  inter- 
costal muscles,  each  artery  gives  off  a  dorsal  branch,  which  passes  back 
between  the  transverse  processes  of  the  ''ertebrae,  lying  internally  to  the 
middle  costo-transverse  ligament,  and  divides  into  a  spinal  branch,  which 
supplies  the  spinal  cord  and  vertebrae,  and  a  muscular  branch  which  is 
distributed  to  the  muscles  and  integument  of  the  back.  The  artery  then 
comes  into  relation  with  its  vein  and  nerve,  the  former  being  above  and 
the  latter  below,  and  divides  into  two  branches  which  run  along  the  bor- 
ders of  contiguous  ribs  between  the  two  planes  of  intercostal  muscles,  and 
anastomose  with  the  anterior  intercostal  arteries,  branches'  of  the  internal 
mammary.  The  branch  corresponding  with  the  lower  border  of  each  rib 
is  the  larger  of  the  two.  They  are  protected  from  pressure  during  the 
action  of  the  intercostal  muscles,  by  little  tendinous  arches  thrown  across 
them  and  attached  by  each  extremity  to  the  bone. 

BRANCHES    OF    THE    ABDOMINAL    AORTA. 

Phrenic, 

C  Gastric, 
Cceliac  axis  <  Hepatic, 

{  Splenic. 

Superior  mesenteric, 
Spermatic, 
Inferior  mesenteric, 
Supra-renal, 
Renal, 
Lumbar, 
Sacra  media. 

The  PHRENIC  ARTERIES  are  given  off  from  the  anterior  part  of  the  aorta 
as  soon  as  that  trunk  has  passed  through  the  aortic  opening.  Passing 
obliquely  outwards  upon  the  under  surface  of  the  diaphragm,  each  artery 
divides  into  two  branches,  an  internal  branch,  which  runs  forwards,  and 
inosculates  with  its  fellow  of  the  opposite  side  in  front  of  the  O3sophag'.-al 
opening ;  and  an  external  branch,  which  proceeds  outwards  towards  the 
great  circumference  of  the  muscle,  and  sends  branches  to  the  supra-renal 
capsules.  The  phrenic  arteries  inosculate  with  branches  of  the  internal 
mammary,  inferior  intercostal,  epigastric,  resophageal,  gastric,  hepatic,  and 
supra-renal  arteries.  They  are  not  unfrequently  derived  from  the  cceliac 
axis,  or  from  one  of  its  divisions,  and  sometimes  they  give  off  the  supra- 
renal arteries. 


•J10 


GASTRIC    AND   HEPATIC    ARTERIES. 


The  CCELIAC  AXIS  (xoiXia,  ventriculus)  is  the  first  single  trunk  given  off 
from  the  abdominal  aorta.  It  arises  opposite  the  upper  border  of  the  first 

lumbar  vertebra,  is  about  half  an 

Fig.  152.*  jnch  jn  length,  and  divides  into 

three  large  branches,  gastric,  he- 
patic, and  splenic. 

Relations.  —  The  trunk  of  the 
cceliac  axis  has  in  relation  with  it, 
in  front,  the  lesser  omentum ;  on 
the  right  side  the  right  semilunar 
ganglion  and  lobus  Spigelii  of  the 
liver;  on  the  left  side  the  left 
semilunar  ganglion  and  cardiac 
portion  of  the  stomach ;  and  below, 
the  upper  border  of  the  pancreas 
and  lesser  curve  of  the  stomach. 
It  is  completely  surrounded  by  the 
solar  plexus. 

The  GASTRIC  ARTERY  (coronaria 
ventriculi),  the  smallest  of  the  three 
branches  of  the  cceliac  axis,  ascends 
between  the  two  layers  of  the  lesser 
omentum  to  the  cardiac  orifice  of 
the  stomach,  then  runs  along  the 
lesser  curvature  to  the  pylorus, 
and  inosculates  with  the  pyloric 
branch  of  the  hepatic.  It  is  dis- 
tributed to  the  lower  extremity  of 
the  oesophagus  and  lesser  curve  of 
the  stomach,  and  anastomoses  with 
the  ffisophageal  arteries  and  vasa  brevia  of  the  splenic  artery. 

The  HEPATIC  ARTERY  curves  forwards,  and  ascends  along  the  right 
border  of  the  lesser  omentum  to  the  liver,  where  it  divides  into  two 
branches  (right  and  left),  which  enter  the  transverse  fissure,  and  are  dis- 
tributed along  the  portal  canals  to  the  right  and  left  lobes. f  It  is  in  rela- 
tion, in  the  right  border  of  the  lesser  omentum,  with  the  ductus  communis 
choledochus  and  portal  vein,  and  is  surrounded  by  the  hepatic  plexus  of 
nerves  and  numerous  lymphatics.  There  are  sometimes  two  hepatic 
arteries,  in  which  case  one  is  derived  from  the  superior  mesenteric 
artery. 

*  The  abdominal  aorta  with  its  branches.  1.  The  phrenic  arteries.  2.  The  cceliac 
axis.  3.  The  gastric  artery.  4.  The  hepatic  artery,  dividing  into  the  right  and  left 
hepatic  branches.  5.  The  splenic  artery,  passing  outwards  to  the  spleen.  6.  The 
supra-renal  artery  of  the  right  side.  7.  The  right  renal  artery,  which  is  longer  than  the 
left,  passing  outwards  to  the  right  kidney.  8.  The  lumbar  arteries.  9.  The  superior 
mesenteric  artery.  10.  The  two  spermatic  arteries.  11.  The  inferior  mesenteric.  artery 
12.  The  sacra  media.  13.  The  common  iliacs.  14.  The  internal  iliac  of  the  right  side. 
15.  The  external  iliac  artery.  16.  The  epigastric  artery.  17.  The  circumflexa  ilii 
artery.  18.  The  femoral  artery. 

f  For  the  mode  of  distribution  of  the  hepatic  artery  within  the  liver,  see  the  "Minute 
Anatomy"  of  that  organ  in  the  Chapter  on  the  Viscera. 


SPLENIC    ARTERY.  31] 

The  Branches  of  the  hepatic  artery  are,  the 
Pyloric, 

Gastro-duodenalis,        \  Gastro-epiploica  dextra, 
(  Pancreatico-duodenalis 
Cystic. 

The  Pyloric  branch,  given  off  from  the  hepatic  near  the  pylorus,  is  dis- 
tributed to  the  commencement  of  the  duodenum  and  to  the  lesser  curve 
of  the  stomach,  where  it  inosculates  with  the  gastric  artery. 

The  Gastro-duodenalis  artery  is  a  short  but  large  trunk,  which  descends 
behind  the  pylorus,  and  divides  into  two  branches,  the  gastro-epiploica 
dextra,  and  pancreatico-duodenalis.  Previously  to  its  division,  it  gives 
off  some  inferior  pyloric  branches  to  the  small  end  of  the  stomach. 

The  Gastro-epiploica  dextra  runs  along  the  great  curve  of  the  stomach 
lying  between  the  two  layers  of  the  great  omentum,  and  inosculates  at 
about  its  middle  with  the  gastro-epiploica  sinistra,  a  branch  of  the  splenic 
artery.  It  supplies  the  great  curve  of  the  stomach  and  the  great  omentum ; 
hence  the  derivation  of  its  name. 

The  Pancreatico-duodenalis  curves  along  the  fixed  border  of  the  duo- 
denum, partly  concealed  by  the  attachment  of  the  pancreas,  and  is  distri- 
buted to  the  pancreas  and  duodenum.  It  inosculates  inferiorly  with  the 
first  jejunal,  and  with  the  pancreatic  branches  of  the  superior  mesenteric 
artery. 

The  Cystic  artery,  generally  a  branch  of  the  right  hepatic,  is  of  small 
size,  and  ramifies  between  the  coats  of  the  gall-bladder,  previously  to  its 
distribution  to  the  mucous  membrane. 

The  SPLENIC  ARTERY,  the  largest  of  the  three  branches  of  the  cceliac 
axis,  passes  horizontally  to  the  left  along  the  upper  border  of  the  pancreas, 
and  divides  into  five  or  six  large  branches,  which  enter  the  hilus  of  the 
spleen,  and  are  distributed  to  its  structure.  In  its  course  it  is  tortuous 
and  serpentine,  and  frequently  makes  a  complete  turn  upon  itself.  It  lies 
in  a  narrow  groove  in  the  upper  border  of  the  pancreas,  and  is  accom- 
panied by  the  splenic  vein,  and  by  the  splenic  plexus  of  nerves. 

The  Branches  of  the  splenic  artery  are  the — • 

Pancreaticse  parvae, 
Pancreatica  magna, 
Vasa  brevia, 
Gastro-epiploica  sinistra. 

The  Pancreatica  parvce  are  numerous  small  branches  distributed  to  the 
pancreas,  as  the  splenic  border  runs  along  its  upper  border.  One  of  these, 
larger  than  the  rest,  follows  the  course  of  the  pancreatic  duct,  and  is  called 
pancreatica  magna. 

The  Vasa  brevia  are  five  or  six  branches  of  small  size  which  pass  from 
the  extremity  of  the  splenic  artery  and  its  terminal  branches,  between  the 
layers  of  the  gastro-splenic  omentum,  to  the  great  end  of  the  stomach,  to 
which  they  are  distributed,  inosculating  with  branches  of  the  gastric  artery 
and  gastro-epiploica  sinistra. 

The  Gastro-epiploica  sinistra  appears  to  be  the  continuation  of  the 
splenic  artery ;  it  passes  forwards  from  left  to  right,  along  the  great  curve 
of  the  stomach,  lying  between  the  layers  of  the  great  omentum,  and  inos- 


312 


SUPERIOR    MESENTERIC    ARTERY. 


culates  with  the  gastro-epiploica  dextra.     It  is  distributed  to  the  gre 
curve  of  the  stomach  and  to  the  great  omentum. 

Fig.  153." 


The  SUPERIOR  MESENTERIC  ARTERY,  the  second  of  the  single  trunks, 
and  next  in  size  to  the  cceliac  axis,  arises  from  the  aorta  immediately  below 
that  vessel,  and  behind  the  pancreas.  It  passes  forwards  between  the 
pancreas  and  transverse  duodenum,  and  descends  within  the  layers  of  the 
mesentery,  to  the  right  iliac  fossa,  where  it  terminates,  very  much  dimi- 
nished in  size.  It  forms  a  curve  in  its  course,  the  convexity  being  directed 
towards  the  left,  and  the  concavity  to  the  right.  It  is  in  relation  near  its 
commencement  with  the  portal  vein ;  and  is  accompanied  by  two  veins, 
and  the  superior  mesenteric  plexus  of  nerves. 

The  branches  of  the  superior  mesenteric  artery  are — 

Vasa  intestini  tenuis, 
Ileo-colica, 
Colica  dextra, 
Colica  media. 

The  Vasa  intestini  tenuis  arise  from  the  convexity  of  the  superior  me- 
senteric artery.  They  vary  from  fifteen  to  twenty  in  number,  and  are  dis- 

*  The  distribution  of  the  branches  of  the  cceliac  axis.  1.  The  liver.  2.  Its  transverse 
fissure.  3.  The  gall-bladder.  4.  The  stomach.  5.  The  entrance  of  the  oesophagus. 
6.  The  pylorus.  7.  The  duodenum,  its  descending  portion.  8.  The  transverse  portion 
of  the  duodenum.  9.  The  pancreas.  10.  The  spleen.  11.  The  aorta.  12.  The  cceliac 
axis.  13.  The  gastric  artery.  14.  The  hepatic  artery.  15.  Its  pyloric  branch.  16.  The 
gastro-duodenalis.  17.  The  gastro-epiploica  dextra.  18.  The  pancreatico-duodenalis, 
inosculating  with  a  branch  from  the  superior  mesenteric  artery.  19.  The  division  of 
the  hepatic  artery  into  its  right  and  left  branches ;  the  right  giving  off  the  cystic  branch. 
W.  The  splenic  artery,  traced  by  dotted  lines  behind  the  stomach  to  the  spleen.  21. 
The  gastro-epiploica  sinistra,  inosculating  along  the  great  curvature  of  the  stomach  with 
the  gastro-epiploica  dextra.  22.  The  pancreatica  magna.  23.  The  vasa  brevia  to  the 
great  end  of  the  stomach,  inosculating  with  branches  of  the  gastric  artery.  24.  The 
superior  mesenteric  artery,  emerging  from  between  the  pancreas  and  transverse  portion 
•f  the  duodenum. 


SUPERIOR   MESENTERIC    ARTERY. 


313 


tributed  to  the  small  intestine  from  the  duodenum  to  the  termination  of  the 
ileum.  In  their  course  between  the  layers  of  the  mesentery,  they  form  a 
series  of  arches  by  the  inosculation  of  their  larger  branches ;  from  these 

Fig.  154.* 


are  developed  secondary  arches,  and  from  the  latter  a  third  series  of  arches, 
from  which  the  branches  arise  which  are  distributed  to  the  coats  of  the  in- 
testine. From  the  middle  branches  a  fourth  and  sometimes  even  a  fifth 
series  of  arches  is  produced.  By  means  of  these  arches  a  direct  commu- 
nication is  established  between  all  the  branches  given  off  from  the  convex- 
ity of  the  superior  mesenteric  artery ;  the  superior  branches  moreover  sup- 
ply the  pancreas  and  duodenum,  and  inosculate  with  the  pancreatico- 
duodenalis ;  and  the  inferior  with  the  ileo-colica. 

The  lleo-colic  artery  is  the  last  branch  given  off  from  the  concavity  of 
the  superior  mesenteric.  It  descends  to  the  right  iliac  fossa,  and  divides 
into  branches  wrhich  communicate  and  form  arches,  from  which  branches 
are  distributed  to  the  termination  of  the  ileum,  the  caecum,  and  the  com- 
mencement of  the  colon.  This  artery  inosculates  on  the  one  hand  with 
the  last  branches  of  the  vasa  intestini  tenuis,  and  on  the  other  with  the  last 
colica  dextra. 

*  The  course  and  distribution  of  the  superior  mesenteric  artery.  1.  The  descending 
portion  of  the  duodenum.  2.  The  transverse  portion.  3.  The  pancreas.  4.  The  jeju- 
num. 5.  The  ileum.  6.  The  caecum,  from  which  the  appendix  vermiformis  is  seen 
projecting.  7.  The  ascending  colon.  8.  The  transverse  colon.  9.  The  commencement 
of  the  descending  colon.  10.  The  superior  mesenteric  artery.  11.  The  eolica  media. 
12.  The  hranch  which  inosculates  with  the  colica  sinistra.  13.  The  branch  of  the  supe- 
rior mesenteric  artery,  which  inosculates  with  the  pancreatico-duodenalis.  14.  The  co 
lica  dextra.  15.  The  ileo-colica.  16,  16.  The  branches  from  the  convexity  of  the  supe- 
rior mesenteric  to  the  small  intestines. 

27 


314  SPERMATIC    ARTERIES. 

The  Colica  dextra  arises  from  about  the  middle  of  the  concavity  of  the 
superior  mesenteric,  and  divides  into  branches  which  form  arches,  and  are 
distributed  to  the  ascending  colon.  Its  descending  branches  inosculate 
with  the  ileo-colica,  and  the  ascending  with  the  colica  media. 

The  Colica  media  arises  from  the  upper  part  of  the  concavity  of  the  su- 
perior mesenteric,  and  passes  forwards  between  the  layers  of  the  transverse 
mesocolon,  where  it  forms  arches,  and  is  distributed  to  the  transverse 
colon.  It  inosculates  on  the  right  with  the  colica  dextra ;  and  on  the  left 
with  the  colica  sinistra,  a  branch  of  the  inferior  mesenteric  artery. 

The  SPERMATIC  ARTERIES  are  two  small  vessels  which  arise  from  the 
front  of  the  aorta  below  the  superior  mesenteric ;  from  this  origin  each 
artery  passes  obliquely  outwards,  and  accompanies  the  corresponding 
ureter  along  the  front  of  the  psoas  muscle  to  the  border  of  the  pelvis, 
where  it  is  in  relation  with  the  external  iliac  artery.  It  is  then  directed 
outwards  to  the  internal  abdominal  ring,  and  follows  the  course  of  tb*» 

Fig.  155* 


The  distribution  and  branches  of  the  inferior  mesenteric  artery.     1,  1.  The  superior 
mesenteric  artery,  with  its  branches  and  the  small  intestines  turned  over  to  the  right 
de.     2.  The  csecui.  and  appendix  cseci.     3.  The  ascending  colon.     4.  The  transverse 
3lon  raised  upwards.     5.  The  descending  colon.     6.  Its  sisrmoid  flexure.     7.  The  rec- 
tum.    8.  The  aorta.     9.  The  inferior  mesenteric  artery.      10.  The  colica  sinistra,  inos- 
culating with,  11,  the  colica  media,  a  branch  of  the  superior  mesenteric  artery.     12,  12 
bigmoid  branches.     13.  The   superior  hsemorrhoidal  artery.     14.  The    pancreas.     15. 
Ihe  descending  portion  of  the  duodenum. 


LUMBAR    ARTERIES.  315 

spermatic  cord  along  the  spermatic  canal  and  through  the  scrotum  to  the 
testicle,  to  which  it  is  distributed.  The  right  spermatic  artery  lies  in  front 
of  the  vena  cava,  and  both  vessels  are  accompanied  by  their  corresponding 
veins  and  by  the  spermatic  plexuses  of  nerves. 

The  spermatic  arteries  in  the  female  descend  into  the  pelvis  and  pass 
between  the  two  layers  of  the  broad  ligaments  of  the  uterus,  to  be  distri 
buted  to  the  ovaries,  Fallopian  tubes,  and  round  ligaments ;  along  the 
latter  they  are  continued  to  the  inguinal  canal  and  labium  at  each  side. 

They  inosculate  with  the  uterine  arteries. 

The  INFERIOR  MESENTERIC  ARTERY,  smaller  than  the  superior,  arises 
from  the  abdominal  aorta,  about  two  inches  below  the  origin  of  that  ves- 
sel, and  descends  between  the  layers  of  the  left  mesocolon,  to  the  left  iliac 
fossa,  where  it  divides  into  three  branches : 

Colica  sinistra, 

SigmoideaB, 

Superior  hsemorrhoidal. 

The  Colica  sinistra  is  distributed  to  the  descending  colon,  and  ascends 
to  inosculate  with  the  colica  media.  This  is  the  largest  arterial  inoscula- 
tion in  the  body. 

The  Sigmoidece  are  several  large  branches  which  are  distributed  to  the 
sigmoid  flexure  of  the  descending  colon.  They  form  arches,  and  inoscu- 
late above  with  the  colica  sinistra,  and  below  with  the  superior  hoemor- 
rhoidal  artery. 

The  Superior  hcemorrhoidal  artery  is  the  continuation  of  the  inferior 
mesenteric.  It  crosses  the  ureter  and  common  iliac  artery  of  the  left  side, 
and  descends  between  the  two  layers  of  the  meso-rectum  as  far  as  the 
middle  of  the  rectum  to  which  it  is  distributed,  anastomosing  with  the 
middle  and  external  hsemorrhoidal  arteries. 

The  SUPRA-RENAL  are  two  small  vessels  which  arise  from  the  aorta  im- 
mediately above  the  renal  arteries,  and  are  distributed  to  the  supra-renal 
capsules.  They  are  sometimes  branches  of  the  phrenic  or  of  the  renal 
arteries. 

The  RENAL  ARTERIES  (emulgent)  are  two  large  trunks  given  off  from 
the  sides  of  the  aorta  immediately  below  the  superior  mesenteric  artery ; 
the  right  is  longer  than  the  left  on  account  of  the  position  of  the  aorta, 
and  passes  behind  the  vena  cava  to  the  kidney  of  that  side.  The  left  is 
somewhat  higher  than  the  right.  They  divide  into  several  large  branches 
previously  to  entering  the  kidney,  and  ramify  very  minutely  in  its  vascular 
portion.  The  renal  arteries  supply  several  small  branches  to  the  supra- 
renal capsules. 

The  LUMBAR  ARTERIES  correspond  with  the  intercostals  in  the  chest ; 
they  are  four  or  five  in  number  on  each  side,  and  curve  around  the  bodies 
of  the  lumbar  vertebrae  beneath  the  psoas  muscles,  and  divide  into  two 
branches  ;  one  of  which  passes  backwards  between  the  transverse  pro- 
cesses, and  is  distributed  to  the  vertebrae  and  spinal  cord  and  to  the  mus 
cles  of  the  back,  whilst  the  other  takes-  its  course  behind  the  quadrat  us 
lumborum  muscle  and  supplies  the  abdominal  muscles.  The  first  lumbar 


#16  COMMON    ILIAC    ARTERIES. 

artery  runs  along  the  lower  border  of  the  last  rib,  and  the  last  along  the 
'jrest  of  the  ilium.  In  passing  between  the  psoas  muscles  and  the  verte- 
brse,  they  are  protected  by  a  series  of  tendinous  arches,  which  defend 
them  and  the  communicating  branches  of  the  sympathetic  nerve  from 
pressure  during  the  action  of  the  muscle. 

The  SACRA  MEDIA  arises  from  the  posterior  part  of  the  aorta  at  its  bifur- 
cation, and  descends  along  the  middle  of  the  anterior  surface  of  the  sacrum 
to  the  first  piece  of  the  coccyx,  where  it  terminates  by  inosculating  with 
the  lateral  sacral  arteries.  It  distributes  branches  to  the  rectum  and  ante- 
rior sacral  nerves,  and  inosculates  on  either  side  with  the  lateral  sacral 
arteries. 

Varieties  in  the  Branches  of  the  Abdominal  Aorta. — The  phrenic  arteries 
are  very  rarely  both  derived  from  the  aorta.  One  or  both  may  be  branches 
of  the  coeliac  axis ;  one  may  proceed  from  the  gastric  artery,  from  the 
renal,  or  from  the  upper  lumbar  artery.  There  are  occasionally  three  or 
more  phrenic  arteries.  The  cceliac  artery  is  very  variable  in  length,  and 
gives  off  its  branches  irregularly.  There  are  sometimes  two  or  even  three 
hepatic  arteries,  one  of  which  may  be  derived  from  the  gastric  or  even 
from  the  superior  mesenteric.  The  colica  media  is  sometimes  derived 
from  the  hepatic  artery.  The  spermatic  arteries  are  very  variable,  both  in 
origin  and  number.  The  right  spermatic  may  be  a  branch  of  the  renal 
artery,  and  the  left  a  branch  of  the  inferior  mesenteric.  The  supra-renal 
arteries  may  be  derived  from  the  phrenic  or  renal  arteries.  The  renal 
arteries  present  several  varieties  in  number ;  there  may  be  three  or  even 
four  arteries  on  one  side,  and  one  only  on,  the  other.  When  there  are 
several  renal  arteries  on  one  side,  one  may  arise  from  the  common  iliac 
artery,  from  the  front  of  the  aorta  near  its  lower  part,  or  from  the  internal 
iliac. 

COMMON    ILIAC     ARTERIES. 

The  abdominal  aorta  divides  opposite  the  fourth  lumbar  vertebra  into 
the  two  common  iliac  arteries.  Sometimes  the  bifurcation  takes  place  as 
high  as  the  third,  and  occasionally  as  low  as  the  fifth  lumbar  vertebra. 
The  common  iliac  arteries  are  about  two  inches  and  a  half  in  length ;  they 
diverge  from  the  termination  of  the  aorta,  and  pass  downwards  and  out- 
wards on  each  side  to  the  margin  of  the  pelvis,  opposite  the  sacro-iliac 
symphysis,  where  they  divide  into  the  internal  and  external  iliac  arteries. 
In  old  persons  the  common  iliac  arteries  are  more  or  less  dilated  and 
curved  in  their  course. 

The  Right  common  iliac  is  somewhat  longer  than  the  left,  and  forms  a 
more  obtuse  angle  with  the  termination  of  the  aorta  j  the  angle  of  bifur- 
cation is  greater  in  the  female  than  in  the  male. 

Eolations.  —  The  relations  of  the  two  arteries  are  different  on  the  two 
sides  of  the  body.  The  right  common  iliac  is  in  relation  in  front  with  the 
peritoneum,  and  is  crossed  at  its  bifurcation  by  the  ureter.  It  is  in  rela- 
tion posteriorly  with  the  two  common  iliac  veins,  and  externally  with  the 
psoas  magnus.  The  left  is  in  relation  in  front  with  the  peritoneum,  and 
is  crossed  by  the  rectum  and  superior  hsemorrhoidal  artery,  and,  at  its 
bifurcation,  by  the  ureter.  It  is  in  relation  behind  with  the  left  common 
iliac  vein,  and  externally  with  the  psoas  magnus. 


INTERNAL    ILIAC    ARTERY. 
INTERNAL    ILIAC    ARTERY. 


317 


The  Internal  Iliac  artery  is  a  short  trunk,  varying  in  length  from  an 
inch  to  two  inches.  It  descends  obliquely  to  a  point  opposite  the  upper 
margin  of  the  great  sacro-ischiatic  foramen,  where  it  divides  into  an  ante- 
nor  and  a  posterior  trunk. 

Fig.  156.» 


Relations. — This  artery  rests  externally  on  the  sacral  plexus  and  on  the 
origin  of  the  pyriformis  muscle ;  posteriorly  it  is  in  relation  with  the  in- 
ternal iliac  vein,  and  anteriorly  with  the  ureter. 

Branches. — The  branches  of  the  anterior  trunk  are  the — 


Umbilical, 
Middle  vesical, 
Middle  haemorrhoidal, 

And  in  the  female  the — 

Uterine, 
And  of  the  posterior  trunk,  the — 

Ilio-lumbar, 
Obturator, 


Ischiatic, 
Internal  pudic. 


Vaginal. 


Lateral  sacral, 
Gluteal. 


The  umbilical  artery  is  the  commencement  of  the  fibrous  cord  into 
which  the  umbilical  artery  of  the  foetus  is  converted  after  birth.  In  after 
life,  the  cord  remains  pervious  for  a  short  distance,  and  constitutes  the 
umbilical  artery  of  the  adult,  from  which  the  superior  vesical  artery  is 
given  off  to  the  fundus  and  anterior  aspect  of  the  bladder.  The  cord  may 

*The  distribution  and  branches  of  the  iliac  arteries.  1.  The  aorta.  2.  The  left  com- 
mon iliac  artery.  3.  The  external  iliac.  4.  The  epigastric  artery.  5.  The  circumflexa 
ilii.  6.  The  internal  iliac  artery.  7.  Its  anterior  trunk.  8.  Its  posterior  trunk.  9.  The 
umbilical  artery  giving  off  (10)  the  superior  vesical  artery.  After  the  origin  of  tins 
branch,  the  umbilical  artery  becomes  converted  into  a  fibrous  cord — the  umbilical  liga- 
ment. 11.  The  internal  pudic  artery  passing  behind  the  spine  of  the  ischium  (12)  and 
lesser  sacro-ischiatic  ligament.  13.  The  middle  haemorrhoidal  artery.  14.  The  ischiatic 
artery,  also  passing  behind  the  anterior  sacro-ischiatic  ligament  to  escape  from  the 
pelvis.  15.  Its  inferior  vesical  branch.  16.  The  ilio-lumbar,  the  first  branch  of  the  pos- 
terior trunk  (8)  ascending  to  inosculate  with  the  circumflexa  ilii  artery  (5)  and  form  an 
arch  along  the  crest  of  the  ilium.  17.  The  obturator  artery.  18.  The  lateral  sacral. 
19.  The  gluteal  artery  escaping  from  the  pelvis  through  the  upper  part  of  the  great 
sacro-ischiatic  foramen.  20.  The  sacra  media.  21.  The  right  common  iliac  arteiycui 
ihort.  22.  The  femoral  ar'ery. 

27* 


318  ISCHIATIC   AND    INTERNAL    PUDIC    ARTERIES. 

be  traced  forwards  by  the  side  of  the  fundus  of  the  bladder  to  near  its 
apex,  whence  it  ascends  by  the  side  of  the  linea  alba  and  urachus  to  the 
umbilicus. 

The  Middle  vesical  artery  is  generally  a  branch  of  the  umbilical,  and 
sometimes  of  the  internal  iliac.  It  is  somewhat  larger  than  the  superior 
vesical,  and  is  distributed  to  the  posterior  part  of  the  body  of  the  bladder, 
the  vesiculae  seminales,  and  prostate  gland. 

The  Middle  heemorrhoidal  artery  is  as  frequently  derived  from  the 
ischiatic  or  internal  pudic  as  from  the  internal  iliac.  It  is  of  variable  size, 
and  is  distributed  to  the  rectum,  base  of  the  bladder,  vesiculae  seminales, 
and  prostate  gland,  and  inosculates  with  the  superior  and  external  hasmor- 
rhoidal  arteries. 

The  ISCHIATIC  ARTERY  is  the  larger  of  the  two  terminal  branches  of  the 
anterior  division  of  the  internal  iliac.  It  passes  downwards  between  the 
posterior  border  of  the  levator  ani  and  the  pyriformis,  resting  on  the  sacral 
plexus  of  nerves,  and  lying  behind  the  internal  pudic  artery,  to  the  lower 
border  of  the  great  ischiatic  notch,  where  it  escapes  from  the  pelvis  below 
the  pyriformis  muscle.  It  then  descends  in  the  space  between  the  tro- 
chanter  major  and  the  tuberosity  of  the  ischium  in  company  with  the 
ischiatic  nerves,  and  divides  into  branches. 

Its  branches  within  the  pelvis  are  heemorrhoidal ,  which  supply  the  rec- 
tum conjointly  with  the  middle  hasmorrhoidal,  and  sometimes  take  the 
place  of  that  artery,  and  the  inferior  vesical,  which  is  distributed  to  the 
base  and  neck  of  the  bladder,  the  vesiculas  seminales,  and  prostate  gland. 
The  branches  externally  to  the  pelvis,  are  four  in  number,  namely,  coccy- 
geal,  inferior  gluteal,  comes  nervi  ischiatici,  and  muscular  branches. 

The  Coccygeal  branch  pierces  the  great  sacro-ischiatic  ligament,  and  is 
distributed  to  the  coccygeus  and  levator  ani  muscles,  and  to  the  integu- 
ment around  the  anus  and  coccyx. 

The  Inferior  gluteal  branches  supply  the  gluteus  maximus  muscle. 

The  Comes  nervi  ischiatici  is  a  small  but  regular  branch,  which  accom- 
panies the  great  ischiatic  nerve  to  the  lower  part  of  the  thigh. 

The  Muscular  branches  supply  the  muscles  of  the  posterior  part  of  the 
hip  and  thigh,  and  inosculate  with  the  internal  and  external  circumflex 
arteries,  with  the  obturator,  and  with  the  superior  perforating  artery. 

The  INTERNAL  PUDIC  ARTERY,  the  other  terminal  branch  of  the  anterior 
mink  of  the  internal  iliac,  descends  in  front  o"f  the  ischiatic  artery  to  the 
lower  border  of  the  great  ischiatic  foramen.  It  emerges  from  the  pelvis 
through  the  great  sacro-ischiatic  foramen  below  the  pyriformis  muscle, 
crosses  the  spine  of  the  ischium,  and  re-enters  the  pelvis  through  the  lesser 
sacro-ischiatic  foramen ;  it  then  crosses  the  internal  obturator  muscle  to 
the  ramus  of  the  ischium,  being  situated  at  about  an  inch  from  the  margin 
of  the  tuberosity,  and  bound  down  by  the  obturator  fascia ;  it  next  ascends 
the  ramus  of  the  ischium,  enters  between  the  two  layers  of  the  deep  pen- 
neal  fascia  lying  along  the  border  of  the  ramus  of  the  os  pubis,  and  at  the 
symphysis  pierces  the  anterior  layer  of  the  deep  perinea!  fascia,  and,  very 
much  diminished  in  size,  reaches  the  dorsum  of  the  penis  along  which  it 
runs,  supplying  that  organ  under  the  name  of  dorsalis  penis. 

Branches. — The  branches  of  the  internal  pudic  artery  within  the  pelvis 
are  several  small  ramuscules  to  the  base  of  the  bladder,  the  vesiculffi  semi- 


INTERNAL    PUDIC    ARTERY. 


319 


nales,  and  the  prostate  gland ;  and  hcsmorrhoidal  branches  which  supply 
the  middle  of  the  rectum,  and  frequently  take  the  place  of  the  middle 
haemorrhoidal  branch  of  the  internal  iliac. 

The  branches  given  off  externally  to  the  pelvis,  are  the 

External  hsemorrhoidal, 
Superficialis  perinei, 
Transversalis  perinei, 
Arteria  bulbosi, 
Arteria  corporis  cavernosi, 
Arteria  dorsalis  penis. 

The  External  hamorrhoidal  arteries  are  three  or  four  small  branches, 
given  off  by  the  internal  pudic  while  behind  the  tuberosity  of  the  ischium. 
They  are  distributed  to  the  anus,  and  to  the  muscles,  the  fascia,  and  the 
integument  of  the  anal  region  of  the  perineum. 

The  Superficial  perimal  artery  is  given  off  near  the  attachment  of  the 
crus  penis ;  it  pierces  the  connecting  layer  of  the  superficial  and  deep 
perineal  fascia,  and  runs  forward  across  the  transversus  perinei  muscle, 
and  along  the  groove  between  the  accelerator  urinae  and  erector  penis  to 
the  septum  scroti,  upon  which  it  ramifies  under  the  name  of  arteria  septi. 
It  distributes  branches  to  the  scrotum,  and  to  the  perineum  in  its  course 
forwards.  One  of  the  latter,  larger  than  the  rest,  crosses  the  perineum, 

Fig.  157.» 


•  The  arteries  of  the  perineum ;  on  the  right  side  the  superficial  arteries  are  seen,  and 
on  the  left  the  deep.  1.  The  penis,  consisting  of  corpus  spongiosum  and  corpus  caver- 
nosum.  The  crus  penis  on  the  left  side  is  cut  through.  2.  The  acceleratores  urinae 
muscles,  enclosing  the  bulbous  portion  of  the  corpus  spongiosum.  3.  The  erector  penis, 
spread  out  upon  the  crus  penis  of  the  right  side.  4.  The  anus,  surrounded  by  the 
sphincter  ani  muscle.  5.  The  ramus  of  the  ischium  and  os  pubis.  6.  The  tuberosity 
of  the  ischium.  7.  The  lesser  sacro-ischiatic  ligament,  attached  by  its  small  extremity 
to  the  spine  of  the  ischium.  8.  The  coccyx.  9.  The  internal  pudic  artery,  crossing  the 
spine  of  the  ischium,  and  entering  the  perineum.  10.  External  haemorrhoidal  branches. 
11.  The  superficialis  perinei  artery,  giving  off  a  small  branch,  transversalis  perinei, 
upon  the  transversus  perinei  muscle.  12.  The  same  artery  on  the  left  side  cut  off.  13. 
The  artery  of  the  bulb.  14.  The  two  terminal  branches  of  the  internal  pudic  artery 
one  is  seen  entering  the  divided  extremity  of  the  crus  penis,  the  artery  of  the  corpu* 
cavernosum  ;  the  other,  the  dorsalis  penis,  ascends  upon  the  dorsum  of  the  organ. 


320  OBTURATOR   ARTERY. 

resting  on  the  transversus  perinei  muscle,  and  is  named  the  transversalis 
perinei. 

The  Artery  of  the  bulb  is  given  off  from  the  pudic  nearly  opposite  the 
opening  for  the  transmission  of  the  urethra ;  it  passes  almost  transversely 
inwards  between  the  two  layers  of  the  deep  perineal  fascia,  and  pierces 
the  anterior  layer  to  enter  the  corpus  spongiosum  at  its  bulbous  extremity. 
It  is  distributed  to  the  corpus  spongiosum. 

The  jlrtery  of  the  corpus  cavernosum  pierces  the  crus  penis,  and  runs 
forward  in  the  interior  of  the  corpus  cavernosum,  by  the  side  of  the  septum 
pectiniforme.  It  ramifies  in  the  parenchyma  of  the  venous  structure  of  the 
corpus  cavernosum. 

The  Dorsal  artery  of  the  penis  ascends  between  the  two  crura  and  sym- 
physispubis  to  the  dorsum  penis,  and  runs  forward,  through  the  suspensory 
ligament,  in  the  groove  of  the  corpus  cavernosum  to  the  glans,  distributing 
branches  in  its  course  to  the  body  of  the  organ  and  to  the  integument. 

The  INTERNAL  PUDIC  artery  in  the  female  is  smaller  than  in  the  male  ; 
its  branches,  with  their  distribution  are,  in  principle,  the  same.  The  su- 
perficial perineal  artery  supplies  the  analogue  of  the  lateral  half  of  the 
scrotum,  viz.  the  greater  labium.  The  artery  of  the  bulb  supplies  the 
meatus  urinarius,  and  the  vestibule  ;  the  artery  of  the  corpus  cavernosum, 
the  cavernous  body  of  the  clitoris,  and  the  arteria  dorsalis  clitoridis,  the 
dorsum  of  that  organ. 

The  UTERINE  and  VAGINAL  arteries  of  the  female  are  derived  either  from 
the  internal  iliac,  or  from  the  umbilical,  internal  pudic,  or  ischiatic  arteries. 
The  former  are  very  tortuous  in  their  course,  and  ascend  between  the 
layers  of  the  broad  ligament,  to  be  distributed  to  the  uterus.  The  lattei 
ramify  upon  the  exterior  of  the  vagina,~and  supply  its  mucous  membrane. 

Branches  of  the  Posterior  Trunk. 

The  ILIO-LUMBAR  ARTERY  ascends  beneath  the  external  iliac  vessels  and 
psoas  muscle,  to  the  posterior  part  of  the  crest  of  the  ilium ;  where  it  di- 
vides into  two  branches,  a  lumbar  branch  which  supplies  the  psoas  and 
iliacus  muscles,  and  sends  a  ramuscule  through  the  fifth  intervertebral  fo- 
ramen to  the  spinal  cord  and  its  membranes ;  and  an  iliac  branch  which 
passes  along  the  crest  of  the  ilium,  distributing  branches  to  the  iliacus  and 
abdominal  muscles,  and  inosculating  with  the  lumbar  and  gluteal  arteries, 
and  with  the  circumflexa  ilii. 

The  OBTURATOR  ARTERY  is  exceedingly  variable  in  point  of  origin ;  it 
generally  proceeds  from  the  posterior  trunk  of  the  internal  iliac  artery,  and 
passes  forwards  a  little  below  the  brim  of  the  pelvis  to  the  upper  border 
of  the  obturator  foramen.  It  there  escapes  from  the  pelvis  through  a  ten- 
dinous arch  formed  by  the  obturator  membrane,  and  divides  into  two 
branches ;  an  internal  branch  which  curves  inwards  around  the  bony 
margin  of  the  obturator  foramen,  between  the  obturator  externus  muscle 
and  tne  ramus  of  the  ischium,  and  distributes  branches  to  the  obturator 
muscles,  the  pectineus,  the  adductor  muscles,  and  to  the  organs  of  gene- 
ration, and  inosculates  with  the  internal  circumflex  artery ;  and  an  external 
branch  which  pursues  its  course  along  the  outer  margin  of  the  obturator 
foramen  to  the  space  between  the  gemellus  inferior  and  quadratus  femoris, 
where  it  inosculates  with  the  ischiatic  artery.  In  its  course  backwards  it 


EXTERNAL    ILIAC    ARTERY.  321 

anastomoses  with  the  internal  circumflex,  and  sends  a  branch  through  the 
notch  in  the  acetabulum  to  the  hip  joint.  Within  the  pelvis  the  obturator 
artery  gives  off  a  branch  to  the  iliacus  muscle,  and  a  small  ramuscule  which 
inosculates  with  the  epigastric  artery. 

The  LATERAL  SACRAL  ARTERIES  are  generally  two  in  number  on  each 
side  ;  superior  and  inferior.  The  superior  passes  inwards  to  the  first  sacral 
foramen,  and  is  distributed  to  the  contents  of  the  spinal  canal,  from  which 
it  escapes  by  the  posterior  sacral  foramen,  and  supplies  the  integument  on 
the  dorsum  of  the  sacrum.  The  inferior  passes  down  by  the  side  of  the 
anterior  sacral  foramina  to  the  coccyx ;  it  first  pierces  and  then  rests  upon 
the  origin  of  the  pyriformis,  and  sends  branches  into  the  sacral 'canal  to 
supply  the  sacral  nerves.  Both  arteries  inosculate  with  each  other  and 
with  the  sacra  media. 

The  GLUTEAL  ARTERY  is  the  continuation  of  the  posterior  trunk  of  the 
internal  iliac :  it  passes  backwards  between  the  lumbo-sacral  and  first  lum- 
bar nerve  through  the  upper  part  of  the  great  sacro-ischiatic  foramen  and 
above  the  pyriformis  muscle,  and  divides  into  three  branches,  superficial, 
deep  superior,  and  deep  inferior. 

The  Superficial  branch  is  directed  forwards,  between  the  gluteus  maxi- 
mus  and  medius,  and  divides  into  numerous  branches,  which  are  distri- 
buted to  the  upper  part  of  the  gluteus  maximus  and  to  the  integument  of 
the  gluteal  region. 

The  Deep  superior  branch  passes  along  the  superior  curved  line  of  the 
ilium,  between  the  gluteus  medius  and  minimus  to  the  anterior  superior 
spinous  process,  where  it  inosculates  with  the  superficial  circumflexa  ilii 
and  external  circumflex  artery.  There  are  frequently  two  arteries  which 
follow  this  course. 

The  Deep  inferior  branches  are  several  large  arteries  which  cross  the 
gluteus  minimus  obliquely  to  the  trochanter  major,  where  they  inosculate 
with  the  branches  of  the  external  circumflex  artery,  and  send  branches 
through  the  gluteus  minimus  to  supply  the  capsule  of  the  hip  joint. 

Varieties  in  the  Branches  of  the  internal  iliac. — The  most  important  of 
the  varieties  occurring  among  these  branches  is  the  origin  of  the  dorsal 
artery  of  the  penis  from  the  internal  iliac  or  ischiatic.  The  artery  in  this 
case  passes  forwards  by  the  side  of  the  prostate  gland,  and  through  the 
upper  part  of  the  deep  perineal  fascia.  It  would  be  endangered  in  the 
operation  of  lithotomy.  The  dorsal  artery  of  the  penis  is  sometimes  de- 
rived from  the  obturator,  and  sometimes  from  one  of  the  external  pudic 
arteries.  The  artery  of  the  bulb,  in  its  normal  course,  passes  almost 
transversely  inwards  to  the  corpus  spongiosum.  Occasionally,  however, 
it  is  so  oblique  in  its  direction  as  to  render  its  division  in  lithotomy  un 
avoidable.  The  obturator  artery  may  be  very  small  or  altogether  want- 
ing, its  place  being  supplied  by  a  branch  from  the  external  iliac  or  epi- 
gastric. 

EXTERNAL     ILIAC    ARTERY. 

The  external  iliac  artery  of  each  side  passes  obliquely  downwards  along 
the  inner  border  of  the  psoas  muscle,  from  opposite  the  sacro-iliac  sym- 
nhysis  to  the  femoral  arch,  where  it  becomes  the  femoral  artery. 

Relations. — It  is  in  relation  in  front  with  the  spermatic  vessels,  the 


#22  EXTERNAL    ILIAC    ARTERY. 

peritoneum,  and  a  thin  layer  of  fascia,  derived  from  the  iliac  fascia,  which 
surrounds  the  artery  and  vein.  At  its  commencement  it  is  crossed  by  the 
ureter,  and  near  its  termination  by  the  crural  branch  of  the  genito-crural 
nerve  and  the  circumflexa  ilii  vein.  Externally  it  lies  against  the  psoas 
muscle,  from  which  it  is  separated  by  the  iliac  fascia ;  and  posteriorly  it  is 
in  relation  with  the  external  iliac  vein,  which,  at  the  femoral  arch,  becomes 
placed  to  its  inner  side.  The  artery  is  surrounded  throughout  the  whole 
of  its  course  by  lymphatic  vessels  and  glands. 

Branches. — Besides  several  small  branches  which  supply  the  glands 
surrounding  the  artery,  the  external  iliac  gives  off  two  branches,  the — 

Epigastric, 
Circumflexa  ilii. 

The  Epigastric  artery  arises  from  the  external  iliac  near  Poupart's  liga- 
ment ;  and  passing  forwards  between  the  peritoneum  and  transversalis 
fascia,  ascends  obliquely  to  tne  sheath  of  the  rectus.  It  enters  the  sheath 
near  its  lower  third,  and  passes  upwards  behind  the  rectus  muscle,  to 
which  it  is  distributed,  and  in  the  substance  of  that  muscle  inosculates, 
near  the  ensiform  cartilage,  with  the  termination  of  the  internal  mammary 
artery.  It  lies  internally  to  the  internal  abdominal  ring  and  immediately 
above  the  femoral  ring,  and  is  crossed  near  its  origin  by  the  vas  deferens 
in  the  male,  and  by  the  round  ligament  in  the  female. 

The  only  branches  of  the  epigastric  artery  wrorthy  of  distinct  notice  are 
the  Cremasteric,  which  accompanies  the  spermatic  cord  and  supplies  the 
cremaster  muscle ;  and  the  ramusculus  which  inosculates  with  the  obtura- 
tor artery. 

The  epigastric  artery  forms  a  prominence  of  the  peritoneum  which  di- 
vides the  iliac  fossa  into  an  internal  and  an  external  portion ;  it  is  from 
the  former  that  direct  inguinal  hernia  issues,  and  from  the  latter,  oblique 
inguinal  hernia. 

The  Circumflexa  ilii  arises  from  the  outer  side  of  the  external  iliac, 
nearly  opposite  the  epigastric  artery.  It  ascends  obliquely  along  Pou- 
part's ligament,  and  curving  around  the  crest  of  the  ilium  between  the 
attachments  of  the  internal  oblique  and  transversalis  muscle,  inosculates 
with  the  ilio-lumbar  and  inferior  lumbar  artery.  Opposite  the  anterior 
superior  spinous  process  of  the  ilium,  it  gives  off  a  large  ascending  branch 
which  passes  upwards  between  the  internal  oblique  and  transversalis,  and 
divides  into  numerous  branches  which  supply  the  abdominal  muscles,  and 
inosculate  with  the  inferior  intercostal  and  with  the  lumbar  arteries. 

Varieties  in  the  branches  of  the  external  iliac. — The  epigastric  artery  not 
unfrequently*  gives  off  the  obturator,  which  descends  in  contact  with  the 
external  iliac  vein,  to  the  obturator  foramen.  In  this  situation  the  artery 
would  lie  to  the  outer  side  of  the  femoral  ring,  and  wrould  not  be  endan- 
gered in  the  operation  for  dividing  the  stricture  of  femoral  hernia.  But 
occasionally  the  obturator  passes  along  the  free  margin  of  Gimbernat's 
ligament  in  its  course  to  the  obturator  foramen,  and  would  completely  en- 
circle the  neck  of  the  hernial  sac, — a  position  in  which  it  could  scarcely 

*  The  proportion  in  which  high  division  of  the  obturator  artery  from  the  epigastric 
occurs,  is  stated  to  be  one  in  three.  In  two  hundred  and  fifty  subjects  examined  by 
Cloquet  with  a  view  to  ascertain  how  frequently  the  high  division  took  place,  he  found 
the  obturator  arising  from  the  epigastric  on  both  sides  one  hundred  and  fifty  times  ;  on 
*ne  side  twenty-eight  times,  and  six  times  it  arose  from  the  femoral  artery. 


FEMORAL    ARTERY. 


323 


escape  the  knife  of  the  operator.  In  a  preparation  in  my  anatomical  col- 
lection, the  branch  of  communication  between  the  epigastric  and  obturator 
arteries  is  very  much  enlarged,  and  takes  this  dangerous  course. 


FEMORAL   ARTERY. 

Emerging  from  beneath  Poupart's  ligament,  the  Fig.  158.* 

external  iliac  artery  enters  the  thigh  and  becomes 
the  femoral.  The  femoral  artery  passes  down  the 
inner  side  of  the  thigh,  from  Poupart's  ligament, 
at  a  point  midway  between  the  anterior  superior 
spinous  process  of  the  ilium  and  the  symphysis 
pubis,  to  the  opening  in  the  adductor  magnus,  at 
the  junction  of  the  middle  with  the  inferior  third 
of  the  thigh,  where  it  becomes  the  popliteal  artery. 

The  femoral  artery  and  vein  are  enclosed  in  a 
strong  sheath,  femoral  or  crural  canal,  which  is 
formed  for  the  greater  part  of  its  extent  by  aponeu- 
rotic  and  areolar  tissue,  and  by  a  process  of  fascia 
sent  inwards  from  the  fascia  lata.  Near  Poupart's 
ligament  this  sheath  is  much  larger  than  the  vessels 
it  contains,  and  is  continuous  with  the  fascia  trans- 
versalis  and  iliac  fascia.  If  the  sheath  be  opened 
at  this  point,  the  artery  will  be  seen  to  be  situated 
in  contact  with  the  outer  wall  of  the  sheath.  The 
vein  lies  next  the  artery,  being  separated  from  it 
by  a  fibrous  septum,  and  between  the  vein  and  the 
inner  wall  of  the  sheath,  and  divided  from  the  vein 
by  another  thin  fibrous  septum,  is  a  triangular  in- 
terval, into  which  the  sac  is  protruded  in  femoral 
hernia.  This  space  is  occupied  in  the  normal  state 
of  the  parts  by  loose  areolar  tissue,  and  by  lympha- 
tic vessels  which  pierce  the  inner  wall  of  the  sheath 
to  make  their  way  to  a  gland,  situated  in  the  femo- 
ral ring. 

Relations.  —  The  upper  third  of  the  femoral  ar- 
tery is  superficial,  being  covered  only  by  the  integument,  inguinal  glands, 

*  A  view  of  the  anterior  and  inner  aspect  of  the  thigh,  showing  the  course  and 
branches  of  the  femoral  artery.  1.  The  lower  part  of  the  aponeurosis  of  the  external 
oblique  muscle;  its  inferior  margin  is  Poupart's  ligament.  2.  The  external  abdominal 
ring.  3,  3.  The  upper  and  lower  part  of  the  sartorius  muscle;  its  middle  portion 
having  been  removed.  4.  The  rectus.  5.  The  vastus  internus.  6.  The  patella.  7. 
The  iliacus  and  psoas ;  the  latter  being  nearest  the  artery.  8.  The  pectineus.  9.  The 
adductor  longus.  10.  The  tendinous  canal  for  the  femoral  artery  formed  by  the,, adduc- 
tor magnus,  and  vastus  internus  muscle.  11.  The  adductor  magnus.  12.  The  gracilis. 
13.  The  tendon  of  the  semi-tendinosus.  14.  The  femoral  artery.  15.  The  superficial 
circumflexa  ilii  artery  taking  its  course  along  the  line  of  Poupart's  ligament,  to  the  crest 
of  the  ilium.  2.  The  superficial  epigastric  artery.  10.  The  two  external  pudic  arteries, 
superficial  and  deep.  17.  The  profunda  artery,  giving  off  18,  its  external  circumflex 
branch ;  and  lower  down  the  three  perforantes.  A  small  bend  of  the  internal  circum 
flex  artery  (8)  is  seen  behind  the  inner  margin  of  the  femoral,  just  below  the  deep  ex 
ternal  pudic  artery.  19.  The  anastomotica  magna,  descending  to  the  knee,  upon  which 
it  ramifies  (6). 


324  FEMORAL   ARTERY. 

and  by  the  superficial  and  deep  fasciae.  The  lower  two-thirds  are  coverea 
by  the  sartorius  muscle.  To  its  outer  side  the  artery  is  first  in  relation 
with  the  psoas  and  iliacus,  and  then  with  the  vastus  internus.  Behind  il 
rests  upon  the  inner  border  of  the  psoas  muscle  ;  it  is  next  separated  from 
the  pectineus  by  the  femoral  vein,  profunda  vein  and  artery,  and  then  lies 
on  the  adductor  longus  to  its  termination :  near  the  lower  border  of  the 
adductor  longus,  it  is  placed  in  an  aponeurotic  canal,  formed  by  an  arch 
of  tendinous  fibres,  thrown  from  the  border  of  the  adductor  longus  and 
the  border  of  the  opening  in  the  adductor  magnus,  to  the  side  of  the 
vastus  internus.  To  its  inner  side  it  is  in  relation  at  its  upper  part  with 
the  femoral  vein,  and  lower  down  with  the  pectineus,  adductor  longus, 
and  sartorius. 

The  immediate  relations  of  the  artery  are  the  femoral  vein,  and  two 
saphenous  nerves.  The  vein  at  Poupart's  ligament  lies  to  the  inner  side 
of  the  artery ;  but  lowyer  down  gets  altogether  behind  it,  and  inclines  to  its 
outer  side.  The  short  saphenous  nerve  lies  to  the  outer  side,  and  some- 
what upon  the  sheath  for  the  lower  two-thirds  of  its  extent ;  and  the  long 
saphenous  nerve  is  situated  wdthin  the  sheath,  and  in  front  of  the  artery 
for  the  same  extent. 

Plan  of  the  Relations  of  the  Femoral  Artery. 

Front. 

Fascia  lata, 

Saphenous  nerves, 

Sartorius, 

Arch  of  the  tendinous  canal. 


Inner  Side. 
Femoral  vein, 
Pectineus, 
Adductor  longus, 
Sartorius. 


Femoral  artery. 


Outer  Side. 
Psoas, 
Iliacus, 
Vastus  internus. 


Behind. 

Psoas  muscle, 
Femoral  vein, 
Adductor  longus. 

Branches. — The  branches  of  the  Femoral  Artery  are  the — 

.Superficial  circumflexa  ilii, 
Superficial  epigastric, 
Superficial  external  pudic, 
Deep  external  pudic, 

C  External  circumflex, 
Profunda    <  Internal  circumflex, 

(  Three  perforating, 
Muscular, 
Anastomotica  magna. 

The  Superficial  circumflexa  ilii  artery  arises  from  the  femoral,  imme- 
diately below  Poupart's  ligament,  pierces  the  fascia  lata,  and  passes  ob- 


PROFUXDA    ARTERY.  325 

liquely  outwards  towards  the  crest  of  the  ilium.  It  supplies  the  integument 
of  the  groin,  the  superficial  fascia,  and  inguinal  glands. 

The  Superficial  epigastric  arises  from  the  femoral,  immediately  below 
Poupart's  ligament,  pierces  the  fascia  lata,  and  ascends  obliquely  towards 
the  umbilicus  between  the  two  layers  of  superficial  fascia.  It  distributes 
branches  to  the  inguinal  glands  and  integument,  and  inosculates  with 
branches  of  the  deep  epigastric  and  internal  mammary  artery. 

The  Superficial  external  pudic  arises  near  the  superficial  epigastric 
artery ;  it  pierces  the  fascia  lata,  at  the  saphenous  opening,  and  passes 
transversely  inwards,  crossing  the  spermatic  cord,  to  be  distributed  to  the 
integument  of  the  penis  and  scrotum  in  the  male,  and  to  the  labia  in  the 
female. 

The  Deep  external  pudic  arises  from  the  femoral,  a  little  lower  down 
than  the  preceding :  it  crosses  the  femoral  vein  immediately  below  the 
termination  of  the  internal  saphenous  vein,  and  piercing  the  pubic  portion 
of  the  fascia  lata,  passes  beneath  that  fascia  to  the  inner  border  of  the 
thigh,  where  it  again  pierces  the  fascia ;  having  become  superficial,  it  is 
distributed  to  the  integument  of  the  scrotum  and  perineum. 

The  PROFUNDA  FEMORIS  arises  from  the  femoral  artery  at  two  inches 
below  Poupart's  ligament :  it  passes  downwards  and  backwards  and  a 
little  outwards,  behind  the  adductor  longus  muscle,  pierces  the  adductor 
magnus,  and  is  distributed  to  the  flexor  muscles  on  the  posterior  part  of 
the  thigh. 

Relations. — In  its  course  downwards  it  rests  successively  upon  the  pecti- 
neus,  the  conjoined  tendon  of  the  psoas  and  iliacus,  adductor  brevis,  and 
adductor  magnus  muscles.  To  its  outer  side  the  tendinous  insertion  of 
the  vastus  internus  muscle  intervenes  between  it  and  the  femur ;  on  its 
inner  side  it  is  in  relation  with  the  pectineus,  adductor  brevis,  and  adduc- 
tor magnus  ;  and  in  front  it  is  separated  from  the  femoral  artery,  above  by 
the  profunda  vein  and  femoral  vein,  and  below  by  the  adductor  longus 
muscle. 

Plan  of  the  Relations  of  the  Profunda  Jlrtery. 

In  Front. 


Profunda  vein, 
Adductor  longus. 


Inner  Side. 

Pectineus, 
Adductor  brevis, 
Adductor  magnus. 


Profunda  artery. 


Outer  Side. 

Psoas  and  iliacus, 
Vastus  internus, 
Femur. 


Behind. 

Pectineus, 

Tendon  of  psoas  and  iliacus, 
Adductor  brevis, 
Adductor  magnus. 


Brandies.— The  branches  of  the  profunda  artery  are,  the  external  cir- 
cumflex, internal  circumflex,  and  three  perforating  arteries. 

The  External  circumflex  artery  passes  obliquely  outwards  between  the. 
28 


326  POPLITEAL    ARTERY. 

divisions  of  the  crural  nerve,  then  between  the  rectus  and  ciureus  muscle, 
and  divides  into  three  branches ;  ascending,  which  inosculates  with  the 
terminal  branches  of  the  gluteal  artery ;  descending,  which  inosculates  with 
the  superior  external  articular  artery ;  and  middle,  which  continues  the 
original  course  of  the  artery  around  the  thigh,  and  anastomoses  with  branches 
of  the  ischiatic,  internal  circumflex,  and  superior  perforating  artery.  It 
supplies  the  muscles  on  the  anterior  and  outer  side  of  the  thigh. 

The  Internal  circumflex  artery  is  larger  than  the  external ;  it  winds 
around  the -inner  side  of  the  neck  of  the  femur,  passing  between  the  pecti- 
neus  and  psoas,  and  along  the  border  of  the  external  obturator  muscle,  to 
the  space  between  the  quadratus  femoris  and  upper  border  of  the  adductor 
magnus,  where  it  anastomoses  with  the  ischiatic,  external  circumflex,  and 
superior  perforating  artery.  It  supplies  the  muscles  of  the  upper  and  inner 
side  of  the  thigh,  anastomosing  with  the  obturator  artery,  and  sends  a  small 
branch  through  the  notch  in  the  acetabulum  into  the  hip  joint. 

The  Superior  perforating  artery  passes  backwards  between  the  pectin eus 
and  adductor  brevis,  pierces  the  adductor  magnus  near  the  femur,  and 
is  distributed  to  the  posterior  muscles  of  the  thigh ;  inosculating  freely 
with  the  circumflex  and  ischiatic  arteries,  and  with  the  branches  of  the 
middle  perforating  artery. 

The  Middle  perforating  artery  pierces  the  tendons  of  the  adductor  brevis 
and  magnus,  and  is  distributed  like  the  superior ;  inosculating  writh  the 
superior  and  inferior  perforantes.  This  branch  frequently  gives  off  the 
nutritious  artery  of  the  femur. 

The  Inferior  perforating  artery  is  given  off  below  the  adductor  brevis, 
and  pierces  the  tendon  of  the  adductor  magnus,  supplying  it  and  the  flexor 
muscles,  and  inosculating  with  the  middle  perforating  artery  above,  and 
with  the  articular  branches  of  the  popliteal  below.  It  is  through  the  me- 
dium of  these  branches  that  the  collateral  circulation  is  maintained  in  the 
limb  after  ligature  of  the  femoral  artery.  • 

The  Muscular  branches  are  given  off  by  the  femoral  artery  throughout 
the  whole  of  its  course.  They  supply  the  muscles  in  immediate  proximity 
with  the  artery,  particularly  those  of  the  anterior  aspect  of  the  thigh.  One 
of  these  branches,  larger  than  the  rest,  arises  from  the  femoral  immediately 
below  the  origin  of  the  profunda,  and  passing  outwards  between  the  rectus 
and  sartorius  divides  into  branches  which  are  distributed  to  all  the  muscles 
of  the  anterior  aspect  of  the  thigh.  This  may  be  named  the  superior  mus- 
cular artery. 

The  Anastomoticamagna  arises  from  the  femoral  while  in  the  tendinous 
canal  formed  by  the  adductors  andvastus  internus.  It  runs  along  the  ten- 
don of  the  adductor  magnus  to  the  inner  condyle,  and  inosculates  with  the 
superior  internal  articular  artery ;  some  of  its  branches  are  distributed  to 
the  vastus  internus  muscle  and  to  the  crureus,  and  terminate  by  anasto- 
mosing with  the  branches  of  the  external  circumflex  and  superior  external 
articular  artery. 


POPLITEAL    ARTERY. 


The  popliteal  artery  (Fig.  160)  commences  from  the  termination  of  tke 
femoral  at  the  opening  in  the  adductor  magnus  muscle,  and  passes  obliquely 
outwards  through  the  middle  of  the  popliteal  space  to  the  lower  border  of 
the  popliteus  muscle,  where  it  divides  into  the  anterior  and  posterior  tibia! 
irtery. 


POPLITEAL    ARTERY.  327 

Relations.— In  its  course  downwards  it  rests  first  on  the  femur,  then  on 
the  posterior  ligament  of  the  knee  joint,  then  on  the  fascia,  covering  the 
popliteus  muscle.  Superficially  it  is  in  relation  with  the  semi-membranosus 
muscle,  next  with  a  quantity  of  fat  which  separates  it  from  the  deep  fascia, 
and  near  its  termination  with  the  gastrocnemius  plantaris,  and  soleus ; 
superficial  and  external  to  it  is  the  popliteal  vein,  and  still  more  superficial 
and  external,  the  popliteal  nerve.  By  its  inner  side  it  is  in  relation  with  the 
semi-membranosus,  internal  condyle  of  the  femur,  and  inner  head  of  the 
gastrocnemius  ;  and  by  its  outer  side  with  the  biceps,  external  condyle  of 
the  femur,  the  outer  head  of  the  gastrocnemius,  the  plantaris  and  the 
soleus. 

Plan  of  the  Relations  of  the  Popliteal  Artery. 

Superficially. 

Semi-membranosus, 
Popliteal  nerve, 
Popliteal  vein, 
Gastrocnemius, 
Plantaris, 
Soleus. 
Inner  Side.  Outer  Side. 


Semi-membranosus, 
Internal  condyle, 
Gastrocnemius. 


Popliteal  Artery. 


Biceps, 

External  condyle, 

Gastrocnemius, 

Plantaris, 
Soleus, 


Deeply. 

Femur, 

Ligamentum  posticum  Winslowii, 

Popliteal  fascia. 

Branches. — The  branches  of  the  popliteal  artery  are  the 

Superior  external  articular, 
Superior  internal  articular, 
Azygos  articular, 
Inferior  external  articular, 
Inferior  internal  articular, 
SuraL 

The  Superior  articular  arteries,  external  and  internal,  wind  around  the 
femur,  immediately  above  the  condyles,  to  the  front  of  the  knee  joint, 
anastomosing  with  each  other,  with  the  external  circumflex,  the  anasto- 
motica  magna,  the  inferior  articular,  and  the  recurrent  of  the  anterior 
tibial.  The  external  passes 'beneath  the  tendon  of  the  biceps,  and  the 
internal  through  an  arched  opening  beneath  the  tendon  of  the  adductor 
magnus.  They  supply  the  knee  joint  and  the  lower  part  of  the  femui. 

The  Azygos  articular  artery  pierces  the  posterior  ligament  of  the  joint, 
the  ligamentum  posticum  Winslowii,  and  supplies  the  synovial  membrane 
in  its  interior.  There  are,  frequently,  several  posterior  articular  arteries. 

The  Inferior  articular  arteries  wind  around  the  head  of  the  tibia  imme- 
diately below  the  joint,  and  anastomose  with  each  other,  the  superior 
articular  arteries,  and  the  recurrent  of  the  anterior  tibial.  The  external 
passes  beneath  the  two  external  lateral  ligaments  of  the  joint,  and  the  in 


328  ANTERIOR    TIBIAL   ARTERY. 

Fig.  150.*  ternal  beneath  the  internal  lateral  ligament.  Tht-y 

supply  the  knee  joint  and  the  heads  of  the  tibia  and 

]Mj/Jjj/l          fibula. 

^  w  '[  The  Swral  arteries  (sura,  the  calf)  are  two  large 

muscular  branches,  which  are  distributed  to  the  two 
heads  of  the  gastrocnemius  muscle. 


ANTERIOR     TIBIAL    ARTERY. 

The  anterior  tibial  artery  passes  forwards  between 
the  two  heads  of  the  tibialis  posticus  muscle,  and 
through  the  opening  in  the  upper  part  of  the  inter- 
osseous  membrane,  to  the  anterior  tibial  region.  It 
then  runs  down  the  anterior  aspect  of  the  leg  to  the 
ankle  joint,  where  it  becomes  the  dorsalis  pedis. 

Relations. — In  its  course  downwards  it  rests  upon 
the  interosseous  membrane  (to  which  it  is  connected 
by  a  little  tendinous  arch  which  is  thrown  across  it), 
the  lower  part  of  the  tibia,  and  the  anterior  ligament 
of  the  joint.  In  the  upper  third  of  its  course  it  is 
situated  between  the  tibialis  anticus  and  extensor 
longus  digitorum,  lower  down  between  the  tibialis 
anticus  and  extensor  proprius  pollicis ;  and  just  be- 
fore it  reaches  the  ankle  it  is  crossed  by  the  tendon 
of  the  extensor  proprius  pollicis,  and  becomes  placed 
between  that  tendon  and  the  tendons  of  the  extensor 
longus  digitorum.  Its  immediate  relations  are  the 
venas  comites  and  the  anterior  tibial  nerve,  which 
latter  lies  at  first  to  its  outer  side,  and  at  about  the 
middle  of  the  leg  becomes  placed  superficially  to 
the  artery. 

Plan  of  the  Relations  of  the  interior  Tibial  Artery. 

Front. 
Deep  fascia, 
Tibialis  anticus, 
Extensor  longus  digitornm, 
Extensor  proprius  pollieis, 
Anterior  tibial  nerve. 


Inner  Side. 
Tibialis  anticus, 
Tendon  of  the  ex- 
tensor   proprius 
pollicis. 


Anterior  Tibial  Artery. 


Outer  Side. 

Anterior  tibial  nerve, 
Extensor  longus  digitornm, 
Extensor  proprius  pollicis, 
Tendons  of  the    eztensoi 
longus  digitorum. 


Behind. 

Interosseous  membrane, 
Tibia  (lower  fourth), 
Ankle  joint. 

•  The  anterior  aspect  of  the  leg  and  foot,  showing  the  anterior  tibial  and  dorsalis 
7'tclis  arteries,  with  their  branches.  1.  The  tendon  of  insertion  of  the  quadriceps  ex 
•e,isor  muscle.  2.  The  insertion  of  the  ligamentum  patella?  into  the  lower  border  of  tLo 
(•ntella.  3.  The  tibia.  4.  The  extensor  proprins  pollicis  muscle.  5.  The  extensor  lon- 
Uus  digitorum.  C.  The  peronei  muscles.  1.  The  inner  belly  of  the  gastrocnemius  and 


DORSALIS    PEDIS    ARTERY.  329 

Branches. — The  branches  of  the  Anterior  Tibial  Artery  are  the — 

Recurrent, 
Muscular, 
External  raalleolar, 
Internal  raalleolar. 

The  Recurrent  branch  passes  upwards  beneath  the  origin  of  the  tibialts 
anticus  muscle  to  the  front  of  the  knee  joint,  upon  which  it  is  distributed, 
anastomosing  with  the  articular  arteries. 

The  Muscular  branches  are  very  numerous,  they  supply  the  muscles  of 
the  anterior  tibial  region. 

The  Malleolar  arteries  are  distributed  to  the  ankle  joint ;  the  external 
passing  beneath  the  tendons 'of  the  extensor  longus  digitorum  and  pero- 
neus  tertius,  inosculates  with  the  anterior  peroneal  artery  and  with  the 
branches  of  the  dorsalis  pedis ;  the  internal,  beneath  the  tendons  of  the 
extensor  proprius  pollicis  and  tibialis  anticus,  inosculates  with  branches 
of  the  posterior  tibial  and  internal  plantar  artery.  They  supply  branches 
to  the  ankle  joint. 

The  DORSALIS  PEDIS  ARTERY  is  continued  forward  along  the  tibial  side 
of  the  dorsurn  of  the  foot,  from  the  ankle  to  the  base  of  the  metatarsal  bone 
of  the  great  toe,  where  it  divides  into  two  branches,  the  dorsalis  hallucis 
and  communicating. 

Relations. — The  dorsalis  pedis  is  situated  along  the  outer  border  of  the 
tendon  of  the  extensor  proprius  pollicis ;  on  its  fibular  side  is  the  inner- 
most tendon  of  the  extensor  longus  digitorum,  and  near  its  termination  il 
is  crossed  by  the  inner  tendon  of  the  extensor  brevis  digitorum.  It  is  ac 
companied  by  vense  comites,  and  has  the  continuation  of  the  anterior  tibial 
nerve  to  its  outer  side. 

Plan  of  the  Relations  of  the  Dorsalis  Pedis  Artery. 

In  Front. 
Integument, 
Deep  fascia, 

Inner  tendon  of  the  extensor 
brevis  digitorum. 


Inner  Side. 

Tendon  of  the  ex- 
tensor proprius 
pollicis. 


Dorsalis  Pedis  Artery. 


Outer  Side. 

Tendon    of  the    extensor 

longus  digitorum, 
Border    of    the    extensor 

brevis  digitorum  muscle. 


Behind. 

Bones  of  the  tarsus,  with 
their  ligaments 

the  soleus.  8.  The  annular  ligament  beneath  which  the  extensor  tendons  and  the  an 
terior  tibial  artery  pass  into  the  dorsum  of  the  foot.  9.  The  anterior  tibial  artery.  10 
Its  recurrent  branch  inosculating  with  (2)  the  inferior  articular,  and  (1)  the  superior 
articular  arteries,  branches  of  the  popliteal.  11.  The  internal  malleolar  artery.  17. 
The  external  malleolar  inosculating  with  the  anterior  peroneal  artery  12.  13.  The  doi- 
salis  pedis  artery.  14.  The  tarsea  and  metatarsea  arteries;  the  tarsea  is  nearest  the 
ankle,  the  metatarsea  is  seen  giving  off  the  interosseEe.  15.  The  dorsalis  hallucis  artory. 
1ft.  The  communicating  branch. 

28* 


330 


POSTERIOR    TIBIAL    ARTERY. 


Fig.  160.* 


Branches. — The  branches  of  this  artery  are  the — 

Tarsea, 

Metatarsea, — interosseae, 

Dorsalis  hallucis, — collateral  digital, 

Communicating. 

The  Tarsea  arches  transversely  across  the  tarsus,  beneath  the  extensor 
brevis  digitorum  muscle,  and  supplies  the  articulations  of  the  tarsal  bones 
and  the  outer  side  of  the  foot ;  it  anastomoses  with  the  external  malleolar, 
I  he  peroneal  arteries,  and  the  external  plantar. 

The  Metatarsea  forms  an  arch  across  the  base  of  the 
metatarsal  bones,  and  supplies  the  outer  side  of  the 
foot ;  anastomosing  with  the  tarsea  and  with  the  exter- 
nal plantar  artery.  The  metatarsea  gives  off  three 
branches,  the  interossea,  which  pass  forward  upon  the 
dorsal  interossei  muscles,  and  divide  into  two  collateral 
branches  for  adjoining  toes.  At  their  commencement 
these  interosseous  branches  receive  the  posterior  per- 
forating arteries  from  the  plantar  arch,  and  opposite  the 
heads  of  the  metatarsal  bones  they  are  joined  by  the 
anterior  perforating  branches  from  the  digital  arteries. 

The  Dorsalis  hallucis  runs  forward  upon  the  first  dor- 
sal interosseous  muscle,  and  at  the  base  of  the  first 
phalanx  divides  into  two  branches,  one  of  which  passes 
inwrards  beneath  the  tendon  of  the  extensor  proprius 
pollicis,  and  is  distributed  to  the  inner  border  of  the 
great  toe,  while  the  other  bifurcates  for  the  supply  of 
the  adjacent  sides  of  the  great  and  second  toe. 

The  Communicating  artery  passes  into  the  sole  of  the 
foot  between  the  two  heads  of  the  first  dorsal  interos- 
seous muscle,  and  inosculates  with  the  termination  of 
the  external  plantar  artery. 

Besides  the  preceding,  numerous  branches  are  dis- 
tributed to  the  bones  and  articulations  of  the  foot,  par- 
ticularly along  the  inner  border  of  the  latter. 

POSTERIOR    TIBIAL    ARTERY. 

The  posterior  tibial  artery  passes  obliquely  down- 
wards along  the  tibial  side  of  the  leg  from  the  lower 

*  A  posterior  view  of  the  leg,  showing  the  popliteal  and  posterior  tibial  artery,  i. 
The  tendons  forming  the  inner  hamstring.  2.  The  tendon  of  the  biceps  forming  the 
outer  hamstring.  3.  The  popliteus  muscle.  4.  The  flexor  longus  digitorum.  5.  The 
t'bialis  posticus.  6.  The  fibula;  immediately  below  the  figure  is  the  origin  of  the  flexor 
longus  pollicis;  the  muscle  has  been  removed  in  order  to  expose  the  peroneal  artery. 
7  The  peronei  muscles,  longus  and  brevis.  8.  The  lower  part  of  the  flexor  longus 
J  illicis  muscle  with  its  tendon.  9.  The  popliteal  artery  giving  off  its  articular  and 
niuscular  brandies ;  the  two  superior  articular  are  seen  in  the  upper  part  of  the  popli- 
teal space  passing  above  the  two  heads  of  the  gastrocnemius  muscle,  which  are  cut 
fnrongh  near  their  origin.  The  two  inferior  are  in  relation  with  the  popliteus  muscle. 
10.  Ihe  anterior  tibial  artery  passing  through  the  angular  interspace  between  the  two 
beads  of  the  tibialis  posticus  muscle.  11.  The  posterior  tibial  artery.  12.  The  relative 
position  of  the  tendons  and  arteiy  at  the  inner  ankle  from  within  outwards,  previously 
to  their  passing  beneath  the  internal  annular  ligament.  13.  The  peroneal  artery,  dividing, 
a  little  below  the  number,  into  two  branches;  the  anterior  peroneal  is  seen  piercing  the 
linerosseous  membrane.  14.  The  posterior  peroneal 


POSTERIOR    TIBIAL    A.\D    PEROXEAL    ARTERIES.  331 

border  of  the  popliteus  muscle  to  the  concavity  of  the  os  calcis,  where  it 
divides  into  the  internal  and  external  plantar  artery. 

Relations. — In  its  course  downwards  it  lies  first  upon  the  tibialis  posti- 
cus,  next  on  the  flexor  longus  digitorum,  and  then  on  the  tibia ;  it  is 
covered  in  by  the  intermuscular  fascia  which  separates  it  above  from  the 
soleus,  and  below  from  the  deep  fascia  of  the  leg  and  the  integument.  It 
is  accompanied  by  its  vena?  comites,  and  by  the  posterior  tibial  nerve, 
which  latter  lies  at  first  to  its  outer  side,  then  superficially  to  it,  and  again 
to  its  outer  side. 

Plan  of  the  Relations  of  the  Posterior  Tibial  Artery. 

Superficially. 

Soleus, 
Deep  fascia, 
The  intermuscular  fascia. 


Inner  Side. 


Vei 


n. 


Posterior  Tibial 
Artery. 


Outer  Side. 

Posterior  tibial  nerve, 
Vein. 


Deeply. 

Tibialis  posticus, 
Flexor  longus  digitorum, 
Tibia. 

Branches. — The  branches  of  the  posterior  tibial  artery  are  the — 

Peroneal,  Internal  calcanean, 

Nutritious,  Internal  plantar, 

Muscular,  External  plantar. 

The  Peroneal  artery  is  given  off  from  the  posterior  tibial  at  about  two 
inches  below  the  lower  border  of  the  popliteus  muscle ;  it  is  nearly  as 
large  as  the  anterior  tibial  artery,  and  passes  obliquely  outwards  to  the 
fibula.  It  then  runs  downwards  along  the  inner  border  of  the  fibula  to 
its  lower  third,  where  it  divides  into  the  anterior  and  posterior  peroneal 
artery. 

Relations. — The  peroneal  artery  rests  upon  the  tibialis  posticus  muscle, 
and  is  covered  in  by  the  soleus,  the  intermuscular  fascia,  and  the  flexor 
ongus  pollicis,  having  the  fibula  to  its  outer  side. 

Plan  of  the  Relations  of  the  Peroneal  Artery. 

In  Front. 

Soleus, 

Intermuscular  fascia, 
Flexor  longus  pollicis. 


Peroneal  Artery. 


Outer  Side. 
Fibula. 


Behind. 
Tibialis  posticus. 


332 


PLANTAR    ARTERIES. 


Branches.  —  The  branches  of  the  peroneal  artery  are,  muscular  to  the 
neighbouring  muscles,  particularly  to  the  soleus,  and  the  two  terminal 
branches  anterior  and  posterior  peroneal. 

The  Anterior  peroneal  pierces  the  interosseous  membrane  at  the  lowei 
third  of  the  leg,  and  is  distributed  on  the  front  of  the  outer  malleolus, 
anastomosing  with  the  external  malleolar  and  tarsal  artery.  This  branch 
is  very  variable  in  size. 

The  Posterior  peroneal  continues  onwards  along  the  posterior  aspect  of 
the  outer  malleolus  to  the  side  of  the  os  calcis,  to  which  and  to  the  mus- 
cles arising  from  it,  it  distributes  external  calcanean  branches.  It  anasto- 
moses with  the  anterior  peroneal,  tarsal,  external  plantar,  and  posterior 
tibial  artery. 

The  Nutritious  artery  of  the  tibia  arises  from  the  trunk  of  the  tibial, 
frequently  above  the  origin  of  the  peroneal,  and  proceeds  to  the  nutritious 
canal,  which  it  traverses  obliquely  from  below  upwards. 

The  Muscular  branches  of  the  posterior  tibial  artery  are  distributed  to 
the  soleus  and  to  the  deep  muscles  on  the  posterior  aspect  of  the  leg.  One 
of  these  branches  is  deserving  of  notice,  a  recurrent  branch,  which  arises 
from  the  posterior  tibial  above  the  origin  of  the  peroneal  artery,  pierces 
the  soleus,  and  is  distributed  upon  the  inner  side  of  the  head  of  the  tibia, 
anastomosing  with  the  inferior  internal  articular. 

The  Internal  calcanean  branches,  three  or  four  in  number,  proceed  from 
the  posterior  tibial  artery  immediately  before  its  division  ;  they  are  distri- 
buted to  the  inner  side  of  the  os  calcis,  to  the  integument,  and  to  the 
muscles  which  arise  from  its  inner  tuberosity,  and  they  anastomose  with 
the  external  calcanean  branches,  and  with  all  the  neighbouring  arteries. 


Fig.  161 .» 


PLANTAR    ARTERIES. 

The  Internal  plantar  artery  proceeds  from  the  bifur- 
cation of  the  posterior  tibial  at  the  inner  malleolus, 
and  passes  along  the  inner  border  of  the  foot  between 
the  abductor  pollicis  and  flexor  brevis  digitorum  mus- 
cles, supplying  the  inner  border  of  the  foot  and  great 
toe. 

The  External  plantar  artery,  much  larger  than  the 
internal,  passes  obliquely  outwards  between  the  first 
and  second  layers  of  the  plantar  muscles,  to  the  fifth 
metatarsal  space.  It  then  turns  horizontally  inwards 
between  the  second  and  third  layers,  to  the  first  meta- 
tarsal space,  where  it  inosculates  with  the  communi- 
cating branch  from  the  dorsalis  pedis.  The  horizontal 
portion  of  the  artery  describes  a  slight  curve,  having 
the  convexity  forwards ;  this  is  the  plantar  arch. 

Branches.  —  The  branches  of  the  external  plantar 
artery  are  the — 

Muscular, 

Articular, 

Digital, — anterior  perforating, 

Posterior  perforating. 

*  The  arteries  of  the  sole  of  the  foot;  the  first  and  a  part  of  the  second  layer  of  mus- 
cles having  been  removed.  1.  The  under  and  posterior  part  of  the  os  calcis  ;  to  which 
the  origins  of  the  first  layei  of  muscles  remain  attached.  2.  The  musculus  accessorius 


VARIETIES  IN  THE  ARTERIES  OF  THE  LOWER  EXTREMITY.      333 

The  Muscular  branches  are  distributed  to  the  muscles  in  the  sole  of  the 
foot. 

The  Articular  branches  supply  the  ligaments  of  the  articulations  of  the 
larsus,  and  their  synovia!  membranes. 

The  Digital  branches  are  four  in  number :  the  first  is  distributed  to  the 
outer  side  of  the  little  toe  ;  the  three  others  pass  forwards  to  the  cleft  be- 
tween the  toes,  and  divide  into  collateral  branches,  which  supply  the 
adjacent  sides  of  the  three  external  toes,  and  the  outer  side  of  the  second. 
At  the  bifurcation  of  the  toes,  a  small  branch  is  sent  upwards  from  each 
digital  artery,  to  inosculate  with  the  interosseous  branches  of  the  metatar- 
sea ;  these  are  the  anterior  perforating  arteries. 

The  Posterior  perforating  are  three  small  branches  which  pass  upwards 
between  the  heads  of  the  three  external  dorsal  interossei  muscles  to  inos- 
culate with  the  arch  formed  by  the  metatarsea  artery. 

Varieties  in  the  Arteries  of  the  Lower  Extremity. — The  femoral  artery 
occasionally  divides  at  Poupart's  ligament  into  two  branches,  and  some- 
times into  three  ;  the  former  is  an  instance  of  the  high  division  of  the  pro- 
funda  artery ;  and  in  a  case  of  the  latter  kind  which  occurred  during  my 
dissections,  the  branches  were  the  profunda,  the  superficial  femoral,  and 
the  internal  circumflex  artery.  Dr.  Quain,  in  his  "  Elements  of  Anatomy," 
records  an  instance  of  a  high  division  of  the  femoral  artery,  in  which  the 
two  vessels  became  again  united  in  the  popliteal  region.  The  point  of 
origin  of  the  profunda  artery  varies  considerably  in  different  subjects, 
being  sometimes  nearer  to  and  sometimes  farther  from  Poupart's  ligament, 
but  more  frequently  the  former.  The  branches  of  the  popliteal  artery  are 
very  liable  to  variety  in  size ;  and  in  all  these  cases  the  compensating 
principle,  so  constant  in  the  vascular  system,  is  strikingly  manifested. 
When  the  anterior  tibial  is  of  small  size,  the  peroneal  is  large ;  and,  in 
place  of  dividing  into  two  terminal  branches  at  the  lower  third  of  the  leg, 
descends  to  the  lower  part  of  the  interosseous  membrane,  and  emerges 
upon  the  front  of  the  ankle,  to  supply  the  dorsum  of  the  foot :  or  the  pos- 
terior tibial  and  plantar  arteries  are  large,  and  the  external  plantar  is  con- 
tinued between  the  heads  of  the  first  dorsal  interosseous  muscle,  to  be 
distributed  to  the  dorsal  surface  of  the  foot.  Sometimes  the  posterior 
tibial  artery  is  small  and  thread-like ;  and  the  peroneal,  after  descending 
to  the  ankle,  curves  inwards  to  the  inner  malleolus,  and  divides  into  the 
two  plantar  arteries.  If,  in  this  case,  the  posterior  tibial  be  sufficiently 
large  to  reach  the  ankle,  it  inosculates  with  the  peroneal  previously  to  its 
division.  The  internal  plantar  artery  sometimes  takes  the  distribution  of 
the  external  plantar,  which  is  short  and  diminutive,  and  the  latter  not  un- 
frequently  replaces  a  deficient  dorsalis  pedis. 

The  varieties  of  arteries  are  interesting  in  the  practical  application  of  a 
knowledge  of  their  principal  forms  to  surgical  operations ;  in  their  tran- 
scendental anatomy,  as  illustrating  the  normal  type  of  distribution  in  ani- 
mals ;  or,  in  many  cases,  as  diverticula  permitted  by  Nature,  to  teach  her 
observers  two  important  principles  -.—first,  in  respect  to  herself,  that,  how- 
ever in  her  means  she  may  indulge  in  change,  the  end  is  never  overlooked, 
and  a  limb  is  as  surely  supplied  by  a  leash  of  arteries,  various  in  their 

3.  The  long  flexor  tendons.  4.  The  tendon  of  the  peroneus  longus.  5.  The  terminatiou 
of  the  posterior  tibial  artery.  6.  The  internal  plantar.  7.  The  external  plantar  artery 
8.  The  plantar  arch  giving  off  four  digital  branches,  which  pass  forwards  on  the  invr 
ossei  muscles.  Three  of  these  arteries  are  seen  dividing,  near  the  heads  of  the  meta 
tarsal  bones,  into  collateral  branches  for  adjoining  toes. 


334  OF    THE    VEINS. 

course,  as  by  those  which  \ve  are  pleased  to  consider  normal  in  distnbu 
tion  ;  and,  secondly,  with  regard  to  us,  that  we  should  ever  be  keenly  alive 
to  what  is  passing  beneath  our  observation,  and  ever  ready  in  the  most 
serious  operation  to  deviate  from  our  course  and  avoid — or  give  eyes  to 
our  knife,  that  it  may  see, — the  concealed  dangers  which  it  is  our  pride 
to  be  able  to  contend  with  and  vanquish. 

PULMONARY    ARTERY. 

The  pulmonary  artery  arises  from  the  left  side  of  the  base  of  the  right 
ventricle  in  front  of  the  origin  of  the  aorta,  and  ascends  obliquely  to  the 
under  surface  of  the  arch  of  the  aorta,  where  it  divides  into  the  right  and 
left  pulmonary  arteries.  In  its  course  upwards  and  backwards  it  inclines 
to  the  left  side,  crossing  the  commencement  of  the  aorta,  and  is  connected 
to  the  under  surface  of  the  arch  by  a  thick  and  impervious  cord,  the  re- 
mains of  the  ductus  arteriosus. 

Relations. — It  is  enclosed  for  one-half  of  its  extent  by  the  pericardium, 
and  receives  the  attachment  of  the  fibrous  portion  of  that  membrane  by  its 
upper  portion.  Behind,  it  rests  against  the  ascending  aorta ;  on  either 
side  is  the  appendix  of  the  corresponding  auricle  with  a  coronary  artery ; 
and  above,  the  cardiac  ganglion  and  the  remains  of  the  ductus  arteriosus. 

The  Right  pulmonary  artery  passes  beneath  the  arch  and  behind  the 
ascending  aorta,  and  in  the  root  of  the  lungs  divides  into  three  branches 
for  the  three  lobes. 

The  Left  pulmonary  artery,  rather  larger  than  the  right,  passes  in  front 
of  the  descending  aorta,  to  the  root  of  the  left  lung,  to  which  it  is  distri- 
buted. These  arteries  divide  and  subdivide  in  the  structure  of  the  lungs, 
and  terminate  in  capillary  vessels  which  form  a  network  around  the  air- 
passages  and  cells,  and  become  continuous  with  the  radicles  of  the  pul- 
monary veins. 

Relations. — In  the  root  of  the  right  lung,  examined  from  above  down- 
wards, the  pulmonary  artery  is  situated  between  the  bronchus  and  pulmo- 
nary veins,  the  former  being  above,  the  latter  below ;  while,  in  the  left 
lung  the  artery  is  the  highest,  next  the  bronchus,  and  then  the  veins.  On 
both  sides,  from  before  backwards,  the  artery  is  situated  between  the  veins 
and  bronchi,  the  former  being  in  front,  and  the  latter  behind. 


CHAPTER   VII. 

OF  THE  VEINS. 

THE  veins  are  the  vessels  which  return  the  blood  to  the  auricles  of  the 
heart,  after  it  has  been  circulated  by  the  arteries  through  the  various  tis- 
sues of  the  body.  They  are  much  thinner  in  structure  than  the  arteries, 
so  that  when  emptied  of  their  blood  they  become  flattened  and  collapsed. 
The  veins  of  the  systemic  circulation  convey  the  dark-coloured  and  im- 
pure or  venous  blood  from  the  capillary  system  to  the  right  auricle  of  the 
heart,  and  they  are  found  after  death  to  be  more  or  less  distended  with 
that  fluid.  The  veins  of  the  pulmonary  circulation  resemble  the  arteries 
of  the  systemic  circulation  in  containing  during  life  the  pure  or  arterial 


STRUCTURE    OF    VEINS.  335 

olood,  which  they  transmit  from  the  capillaries  of  the  lungs  to  the  left 
auricle. 

The  veins  commence  by  minute  radicles  in  the  capillaries  which  are 
everywhere  distributed  through  the  textures  of  the  body,  and  converge  to 
constitute  larger  and  larger  branches,  till  they  terminate  in  the  main  trunks 
which  convey  the  venous  blood  directly  to  the  heart.  In  diameter  they 
are  larger  than  the  arteries,  and,  like  those  vessels,  their  combined  arese 
would  constitute  an  imaginary  cone,  whereof  the  apex  is  placed  at  the 
heart,  and  the  base  at  the  surface  of  the  body.  It  follows  from  this  ar- 
rangement, that  the  blood  in  returning  to  the  heart  is  passing  from  a  larger 
into  a  smaller  channel,  and  therefore  that  it  increases  in  rapidity  during 
its  course. 

Veins  admit  of  a  threefold  division  into,  superficial,  deep,  and  sinuses. 

The  Superficial  veins  return  the  blood  from  the  integument  and  super- 
ficial structures,  and  take  their  course  between  the  layers  of  the  superficial 
fascia;  they  then  pierce  the  deep  fascia  in  the  most  convenient  and  pro- 
tected situations,  and  terminate  in  the  deep  veins.  They  are  unaccompa- 
nied by  arteries,  and  are  the  vessels  usually  selected  for  venesection. 

The  Deep  veins  are  situated  among  the  deeper  structures  of  the  body, 
and  generally  in  relation  with  the  arteries  ;  in  the  limbs  they  are  enclosed 
in  the  same  sheath  with  those  vessels,  and  they  return  the  venous  blood 
from  the  capillaries  of  the  deep  tissues.  In  company  with  all  the  smaller, 
and  also  with  the  secondary  arteries,  as  the  brachial,  radial,  and  ulnar  in 
the  upper,  and  the  tibial  and  peroneal  in  the  lower  extremity,  there  are 
two  veins,  placed  one  on  each  side  of  the  artery,  and  named  vence  comites. 
The  larger  arteries,  as  the  axillary,  subclavian,  carotid,  popliteal,  femoral, 
&c.,  are  accompanied  by  a  single  venous  trunk.  Siiiuses  differ  from  veins 
in  their  structure  ;  and  also  in  their  mode  of  distribution,  being  confined 
to  especial  organs  and  situated  within  their  substance.  The  principal 
venous  sinuses  are  those  of  the  dura  mater,  the  diploe,  the  cancellous 
structure  of  bones,  and  the  uterus. 

The  communications  between  veins  are  even  more  frequent  than  those 
of  arteries,  and  they  take  place  between  the  larger  as  well  as  among  the 
smaller  vessels  ;  the  vense  comites  communicate  with  each  other  very  fre- 
quently in  their  course,  by  means  of  short  transverse  branches  which  pass 
across  from  one  to  the  other.  These  communications  are  strikingly  ex- 
hibited in  the  frequent  inosculations  of  the  spinal  veins,  and  in  the  various 
venous  plexuses,  as  the  spermatic  plexus,  vesical  plexus,  &c.  The  office 
of  these  inosculations  is  very  apparent,  as  tending  to  obviate  the  obstruc- 
tions to  which  the  veins  are  particularly  liable  from  the  thinness  of  their 
coats,  and  from  their  inability  to  overcome  much  impediment  by  the  force 
of  their  current. 

Veins,  like  arteries,  are  composed  of  three  coats,  external  or  areolo- 
fibrous,  middle  or  fibrous,  and  internal  or  serous.  The  external  coat  is 
firm  and  strong,  and  resembles  that  of  arteries.  The  middle  coat  consists 
of  t\vo  layers,  an  outer  layer  of  contractile  fibrous  tissue  disposed  in  a  cir- 
cular direction  around  the  vessel,  and  an  inner  layer  of  organic  muscular 
fibres  arranged  longitudinally.  This  latter  resembles  the  inner  layer  of 
the  middle  coat  of  arteries,  but  is  somewhat  thicker ;  it  is  not  unfrequently 
hypertrophied.  The  internal  coat,  as  in  arteries,  consists  of  a  striated  or 
fenestrated  layer,  and  a  layer  of  epithelium ;  it  is  continuous  wuh  the  in- 
ternal coat  of  arteries  through  the  medium  of  the  lining  membrane  of  UM> 


336  VEINS    OF    THE    HEAD    AND    NECK. 

heart  on  the  one  hand,  and  through  the  capillary  vessels  on  the  other. 
The  differences  in  structure,  therefore,  between  arteries  and  veins,  relate 
to  the  difference  of  thickness  of  their  component  layers,  and  to  the  absence 
of  the  elastic  coat  in  the  latter.  Moreover,  another  difference  occurs  in 
the  presence  of  valves.  The  valves  of  veins  are  composed  of  a  thin  layer 
of  fibrous  membrane,  lined  upon  its  two  surfaces  by  epithelium.  The 
segments  or  flaps  of  the  valves  of  veins  are  semilunar  in  form  and  arranged 
in  pairs,  one  upon  either  side  of  the  vessel ;  in  some  instances  there  is  but 
a  single  flap,  which  has  a  spiral  direction,  and  occasionally  there  are  three. 
The  free  border  of  the  valvular  flaps  is  concave,  and  directed  forwards, 
so  that  while  the  current  of  blood  is  permitted  to  flow  freely  towards  the 
heart,  the  valves  are  distended  and  the  current  intercepted  if  the  stream 
become  retrograde  in  its  course.  Upon  the  cardiac  side  of  each  valve  the 
vein  is  expanded  into  two  pouches  (sinuses),  corresponding  with  the  flaps 
of  the  valves,  which  give  to  the  distended  or  injected  vein  a  knotted  ap- 
pearance. The  valves  are  most  numerous  in  the  veins  of  the  extremities, 
particularly  in  the  deeper  veins,  and  they  are  generally  absent  in  the  very 
small  veins,  and  in  the  veins  of  the  viscera,  as  in  the  portal  and  cerebral 
veins :  they  are  also  absent  in  the  large  trunks,  as  in  the  vense  cavse,  vena^ 
azygos,  innominatae,  and  iliac  veins. 

Sinuses  are  venous  channels,  excavated  in  the  structure  of  an  organ, 
and  lined  by  the  internal  coat  of  the  veins  ;  of  this  structure  are  the  sinuses 
of  the  dura  mater,  whose  external  covering  is  the  fibrous  tissue  of  the 
membrane,  and  the  internal,  the  serous  layer  of  the  veins.  The  external 
investment  of  the  sinuses  of  the  uterus  is  the  tissue  of  that  organ ;  and  that 
of  the  bones,  the  lining  membrane  of  the  cells  and  canals. 

Veins,  like  arteries,  are  supplied  with  nutritious  vessels,  the  vasa  vaso- 
rum ;  and  it  is  to  be  presumed  that  nervous  filaments  are  distributed  in 
their  coats. 

I  shall  describe  the  veins  according  to  the  primary  division  of  the  body, 
taking  first,  those  of  the  head  and  neck ;  next,  those  of  the  upper  extre- 
mity ;  then,  those  of  the  lower  extremity ;  and  lastly,  the  veins  of  the 
trunk. 

VEINS  OF  THE  HEAD  AND  NECK. 

The  veins  of  the  head  and  neck  may  be  arranged  into  three  groups,  viz. 
1.  Veins  of  the  exterior  of  the  head.  2.  Veins  of  the  diploe  and  interior 
of  the  cranium.  3.  Veins  of  the  neck. 

The  veins  of  the  exterior  of  the  head  are  the — 

Facial, 

Internal  maxillary, 

Temporal, 

Temporo-maxillary, 

Posterior  auricular, 

Occipital. 

The  Facial  vein  commences  on  the  anterior  part  of  the  skull  in  a  venous 
plexus,  formed  by  the  communications  of  the  branches  of  the  temporal, 
and  descends  along  the  middle  line  of  the  forehead,  under  the  name  of 
frontal  vein,  to  the  root  of  the  nose,  where  it  is  connected  with  its  fellow 
of  the  opposite  side  by  a  communicating  trunk  which  constitutes  the  nasal 
zrrh.  There  are  usually  two  frontal  veins,  which  communicate  by  a  trans- 


VEINS    OF   THE    DIPLOE.  337 

verse  inosculation  ;  but  sometimes  the  vein  is  single  and  bifurcates  at  the 
root  of  the  nose,  into  the  two  angular  veins.  From  the  nasal  arch,  the 
frontal  is  continued  downwards  by  the  side  of  the  root  of  the  nose,  under 
the  name  of  the  angular  vein  ;  it  then  passes  beneath  the  zygomatic  mus- 
cles and  becomes  the  facial  vein,  and  descends  along  the  anterior  border 
of  the  masseter  muscle,  crossing  the  body  of  the  lower  jaw,  by  the  side  of 
the  facial  artery,  to  the  submaxillary  gland,  and  from  thence  to  the  inter- 
nal jugular  vein  in  which  it  terminates. 

The  branches  which  the  facial  vein  receives  in  its  course  are,  the  supra- 
orbital,  which  joins  the  frontal  vein ;  the  dorsal  veins  of  the  nose  which 
terminate  in  the  nasal  arch ;  the  ophthalmic,  which  communicates  with 
the  angular  vein ;  the  palpebral  and  nasal,  which  open  into  the  angular 
vein  ;  a  considerable  trunk,  the  alveolar,  which  returns  the  blood  from  the 
spheno-maxillary  fossa,  from  the  infra-orbital,  palatine,  vidian,  and  spheno- 
palatine  veins,  and  joins  the  facial  beneath  the  zygomatic  process  of  the 
superior  maxillary  bone,  and  the  veins  corresponding  with  the  branches 
of  the  facial  artery. 

The  Internal  maxillary  vein  receives  the  branches  from  the  zygomatic 
and  pterygoid  fossae ;  these  are  so  numerous  and  communicate  so  freely  as 
to  constitute  a  pterygoid  plexus.  Passing  backwards  behind  the  neck  of 
the  lower  jaw,  the  internal  maxillary  joins  with  the  temporal  vein,  and  the 
common  trunk  resulting  from  this  union  constitutes  the  temporo-maxillary 
vein. 

The  Temporal  vein  commences  on  the  vertex  of  the  head  by  a  plexiform 
network  which  is  continuous  wyith  the  frontal,  the  temporal,  auricular,  and 
occipital  veins.  The  ramifications  of  this  plexus  form  an  anterior  and  a  pos- 
terior branch  which  unite  immediately  above  the  zygoma ;  the  trunk  is  here 
joined  by  another  large  vein,  the  middle  temporal,  which  collects  the  blood 
from  the  temporal  muscle,  and  around  the  outer  segment  of  the  orbit,  and 
pierces  the  temporal  fascia  near  the  root  of  the  zygoma.  The  temporal 
vein  then  descends  between  the  meatus  auditorius  externus  and  the  con- 
dyle  of  the  lower  jaw,  and  unites  with  the  internal  maxillary  vein,  to  form 
the  temporo-maxillary. 

The  Temporo-maxillary  vein  formed  by  the  union  of  the  temporal  and 
internal  maxillary,  passes  downwards  in  the  substance  of  the  parotid  gland 
to  its  lower  border,  where  it  becomes  the  external  jugular  vein.  It  receives 
in  its  course  the  anterior  auricular,  masseteric,  transverse  facial,  and  paro- 
tid  veins,  and  near  its  termination  is  joined  by  the  posterior  auricular  vein. 

The  Posterior  auricular  vein  communicates  with  the  plexus  upon  the 
vertex  of  the  head,  and  descends  behind  the  ear  to  the  temporo-maxillary 
vein,  immediately  before  that  vessel  merges  in  the  external  jugular.  It 
receives  in  its  course  the  veins  from  the  external  ear  and  \he*stylo-mastoid 
vein. 

The  Occipital  vein  commencing  posteriorly  in  the  plexus  of  the  vertex 
of  the  head,  follows  the  direction  of  the  occipital  artery,  and  passing  deeply 
beneath  the  muscles  of  the  back  part  of  the  neck,  terminates  in  the  internal 
jugular  vein.  This  vein  communicates  with  the  lateral  sinus  by  means  of 
a  large  branch  which  passes  through  the  mastoid  foramen,  the  mastoid  vein. 

VEINS    OF    THE    DIPLOL. 

The  diploe  of  the  bones  of  the  head  is  furnished  in  the  adult  with  irregu- 
lar sinuses,  which  are  formed  by  a  continuation  of  the  internal  coat  of  tht: 
29  w 


338  SINUSES    OF    THE    DURA    MATER. 

veins  5nto  the  osseous  canals  in  which  they  are  lodged.  At  the  middle 
period  of  life  these  sinuses  are  confined  to  the  particular  bones ;  but  in  old 
age,  after  the  ossification  of  the  sutures,  they  may  be  traced  from  one  bone 
to  the  next.  They  receive  their  blood  from  the  capillaries  supplying  the 
cellular  structure  of  the  diploe,  and  terminate  externally  in  the  veins  of  the 
pericranium,  and  internally  in  the  veins  and  sinuses  of  the  dura  mater. 
These  veins  are  separated  from  the  bony  walls  of  the  canals  by  a  thin  layer 
of  medulla. 

CEREBRAL  AND  CEREBELLAR  VEINS. 

The  cerebral  veins  are  remarkable  for  the  absence  of  valves,  and  for  the 
extreme  tenuity  of  their  coats.  They  may  be  arranged  into  the  superficial, 
and  deep  or  ventricular  veins. 

The  Superficial  cerebral  veins  are  situated  on  the  surface  of  the  hemi- 
spheres, lying  in  the  grooves  formed  by  the  convexities  of  the  convolutions. 
They  are  named  from  the  position  which  they  may  chance  to  occupy  upon 
the  surface  of  this  organ,  either  superior  or  inferior,  internal  or  external, 
anterior  or  posterior. 

The  Superior  cerebral  veins,  seven  or  eight  in  number  on  each  side,  pass 
obliquely  forwards,  and  terminate  in  the  superior  longitudinal  sinus,  in  the 
opposite  direction  to  the  course  of  the  stream  of  blood  in  the  sinus. 

The  Deep  or  Ventricular  veins  commence  within  the  lateral  ventricles  by 
the  veins  of  the  corpora  striata  and  those  of  the  choroid  plexus,  which  unite 
to  form  the  two  venae  Galeni. 

The  Vena  Galeni  pass  backwards  in  the  structure  of  the  velum  interpo- 
situm;  and  escaping  through  the  fissure  of  Bichat,  terminate  in  the  straight 
sinus. 

The  Cerebellar  veins  are  disposed,  like  those  of  the  cerebrum,  on  the 
surface  of  the  lobes  of  the  cerebellum  ;  they  are  situated  some  upon  the 
superior,  and  some  upon  the  inferior  surface,  while  others  occupy  the 
borders  of  the  organ.  They  terminate  in  the  lateral  and  petrosal  sinuses. 

SINUSES     OF    THE    DURA    MATER. 

The  sinuses  of  the  dura  mater  are  irregular  channels,  formed  by  the 
splitting  of  the  layers  of  that  membrane,  and  lined  upon  their  inner  surface 
by  a  continuation  of  the  internal  coat  of  the  veins.  They  may  be  divided 
into  two  groups: — 1.  Those  situated  at  the  upper  and  back  part  of  the 
skull.  2.  The  sinuses  at  the  base  of  the  skull.  The  former  are,  the 

Superior  longitudinal  sinus, 
Inferior  longitudinal  sinus, 
Straight  sinus, 
Occipital  sinuses, 
Lateral  sinuses. 

The  Superior  longitudinal  sinus  is  situated  in  the  attached  margin  of 
Vhe  falx  cerebri,  and  extends  along  the  middle  line  of  the  arch  of  the  skull, 
(rom  the  foramen  caecum  in  the  frontal,  to  the  inner  tuberosity  of  the  occi- 
pital bone,  where  it  divides  into  the  two  lateral  sinuses.  It  is  triangular 
in  form,  is  small  in  front,  and  increases  gradually  in  size  as  it  passes 
Backwards ;  it  receives  the  superior  cerebral  veins,  which  open  into  it 
obliquely,  numerous  small  veins  from  the  diploe,  and  near  the  posterior 


LATERAL    SINUSES. 


339 


Fig.  162  • 


extremity  of  the  sagittal  suture 
the  parietal  veins,  from  the  peri- 
cranium and  scalp.  Examined 
in  its  interior,  it  presents  numer- 
ous transverse  fibrous  bands  (tra- 
beculoe),  the  chordae  Willisii, 
which  are  stretched  across  its 
inferior  angle ;  and  some  small 
white  granular  masses,  the  glan- 
duloe  Pacchioni ;  the  oblique 
openings  of  the  cerebral  veins, 
with  their  valve-like  margin,  are 
also  seen  on  the  walls  of  the 
sinus. 

The  termination  of  the  supe- 
rior longitudinal  sinus  in  the  two 
lateral  sinuses  forms  a  considera- 
ble dilatation,  into  which  the  straight  sinus  opens  from  the  front,  and  the 
occipital  sinuses  from  below.  This  dilatation  is  named  the  torcular 
Herophili,\  and  is  the  point  of  communication  of  six  sinuses,  the  superior 
longitudinal,  two  lateral,  two  occipital,  and  the  straight. 

The  Inferior  longitudinal  sinus  is  situated  in  the  free  margin  of  the  falx 
cerebri ;  it  is  cylindrical  in  form,  and  extends  from  near  the  crista  galli  to 
the  anterior  border  of  the  tentorium,  where  it  terminates  in  the  straight 
sinus.  It  receives  in  its  course  several  veins  from  the  falx. 

The  Straight  or  fourth  sinus  is  the  sinus  of  the  tentorium ;  it  is  situated 
at  the  line  of  union  of  the  falx  with  the  tentorium ;  is  prismoid  in  form, 
and  extends  across  the  tentorium,  from  the  termination  of  the  inferior  lon- 
gitudinal sinus  to  the  torcular  Herophili.  It  receives  the  vena?  Galeni, 
the  cerebral  veins  from  the  inferior  part  of  the  posterior  lobes,  and  the 
superior  cerebellar  veins. 

The  Occipital  sinuses  are  two  canals  of  small  size,  situated  in  the  at- 
tached border  of  the  falx  cerebelli ;  they  commence  by  several  small  veins 
around  the  foramen  magnum,  and  terminate  by  separate  openings  in  the 
torcular  Herophili.  They  not  unfrequently  communicate  with  the  termi- 
nation of  the  lateral  sinuses. 

The  Lateral  sinuses,  commencing  at  the  torcular  Herophili,  pass  hori 
zontally  outwards,  in  the  attached  margin  of  the  tentorium,  and  then  curve 
downwards  and  inwards  along  the  base  of  the  petrous  portion  of  the  tem- 
poral bone,  at  each  side,  to  the  foramina  lacera  posteriora,  where  they  ter 
minate  in  the  internal  jugular  veins.  Each  sinus  rests  in  its  course  on  the 
transverse  groove  of  the  occipital  bone,  posterior  inferior  angle  of  the 
parietal,  mastoid  portion  of  the  temporal,  and  again  on  the  occipital  bone. 
They  receive  the  cerebral  veins  from  the  inferior  surface  of  the  posterior 

•  The  sinuses  of  the  tipper  and  back  part  of  the  skull.  1.  The  superior  longitudinal 
sinus.  2,  2.  The  cerebral  veins  opening  into  the  sinus  from  behind  forwards.  3.  The 
falx  cerebri.  4  The  inferior  longitudinal  sinus.  5.  The  straight  or  fourth  sinus.  6. 
The  venae  Galeni.  7.  The  torcular  Herophili.  8.  The  two  lateral  sinuses,  with  tho 
occipital  sinuses  between  them.  9.  The  termination  of  the  inferior  petrosal  sinus  of 
•>ne  side.  10.  The  dilatations  corresponding  with  the  jugular  fossae.  11.  The  internal 
yugular  veins. 

j-  Torcular  (a  press),  from  a  supposition  entertained  by  the  older  anatomists  that  the 
columns  of  blood,  coming  in  different  directions,  compressed  each  other  at  this  point 


340 


SUPERIOR    PETROSAL   SINUSES. 


Fig.  163.« 


lobes,  the  inferior  cerebellar  veins,  the  superior  petrosal  sinuses,  the  mas- 
toid,  and  posterior  condyloid  veins,  and  at  their  termination,  the  inferior 
petrosal  sinuses.  These  sinuses  are  often  unequal  in  size,  the  right  being 
larger  than  the  left. 

The  sinuses  of  the  base  of  the  skull  are  the — 

Cavernous, 
Inferior  petrosal, 
Circular, 

Superior  petrosal, 
Transverse. 

The  Cavernous  sinuses  are  named  from  presenting  a  structure  similar  to 
that  of  the  corpus  cavernosum  penis.  They  are  situated  on  each  side  of 
the  sella  turcica,  receiving,  anteriorly,  the  ophthalmic  veins  through  the 
sphenoidal  fissures,  and  terminating  posteriorly  in  the  inferior  petrosal 
sinuses.  In  the  internal  wall  of  each  cavernous  sinus  is  the  inteinal  carotid 
artery,  accompanied  by  several  filaments  of  the  carotid  plexus,  and  crossed 
by  the  sixth  nerve  ;  and,  in  its  external  wall,  the  third,  fourth,  and  oph- 
thalmic nerves.  These  structures  are  separated  from  the  blood  flowing 
through  the  sinus,  by  the  tubular  lining  membrane.  The  cerebral  veins 
from  the  under  surface  of  the  anterior  lobes  open  into  the  cavernous 
sinuses.  They  communicate  by  means  of  the  ophthalmic  with  the  facial 
veins,  by  the  circular  sinus  with  each  other,  and  by  the  superior  petrosal 
•with  the  lateral  sinuses. 

The  Inferior  petrosal  sinuses  are  the  con- 
tinuations of  the  cavernous  sinuses  back- 
wards along  the  lower  border  of  the  petrous 
portion  of  the  temporal  bone  at  each  side  of 
the  base  of  the  skull,  to  the  foramina  lac  era 
posteriora,  where  they  terminate  with  the 
lateral  sinuses  in  the  commencement  of  the 
internal  jugular  veins. 

The  Circular  sinus  (sinus  of  Ridley)  is 
situated  in  the  sella  turcica,  surrounding  the 
pituitary  gland,  and  communicating  on  each 
side  with  the  cavernous  sinus.  The  poste- 
rior segment  is  larger  than  the  anterior. 

The  Superior  petrosal  sinuses  pass  ob- 
liquely backwards  along  the  attached  border 
of  the  tentorium,  on  the  upper  margin  of  the 
petrous  portion  of  the  temporal  bone,  and 
establish  a  communication  between  the  ca- 
vernous and  lateral  sinus  at  each  side.  They 
receive  one  or  two  cerebral  veins  from  the 
inferior  part  of  the  middle  lobes,  and  a  cerebellar  vein  from  the  anterior 
border  of  the  cerebellum.  Near  the  extremity  of  the  petrous  bone  these 
sinuses  cross  the  oval  aperture  which  transmits  the  fifth  nerve. 

*  The  sinuses  of  the  base  of  the  skull.  1.  The  ophthalmic  veins.  2.  The  cavernous 
sinus  of  one  side.  3.  The  circular  sinus  ;  the  figure  occupies  the  position  of  the  pituitary 
gland  in  the  sella  turcica.  4.  The  inferior  petrosal  sinus.  5.  The  transverse  or  ante- 
rior  occipital  sinus.  6.  The  superior  petrosal  sinus.  7.  The  internal  jugular  vein. 
8.  The  foramen  magnum.  9.  The  occipital  sinuses.  10.  The  torcular  Herophili.  11. 
1  .  The  lateral  sinuses. 


VEINS    OF    THE    NECK.  341 

The  Transverse  sinus  (basilar,  anterior  occipital)  passes  transversely 
across  the  basilar  process  of  the  occipital  bone,  forming  a  communication 
between  the  two  inferior  petrosal  sinuses.  Sometimes  there  are  two  si- 
nuses in  this  situation. 

VEINS    OF    THE    NECK. 

The  veins  of  the  neck  which  return  the  blood  from  the  head  are  the 

External  jugular, 
Anterior  jugular, 
Internal  jugular, 
Vertebral. 

The  External  jugular  vein  is  formed  by  the  union  of  the  posterior  auri- 
cular vein  with  the  temporo-maxillary,  and  commences  at  the  lower  bor- 
der of  the  parotid  gland,  in  front  of  the  sterno-mastoid  muscle.  It  de- 
scends the  neck  in  the  direction  of  a  line  drawn  from  the  angle  of  the 
lower  jaw  to  the  middle  of  the  clavicle,  crosses  the  sterno-mastoid,  and 
terminates,  near  the  posterior  and  inferior  attachment  of  that  muscle,  in 
the  subclavian  vein.  In  its  course  downwards  it  lies  upon  the  anterior 
lamella  of  the  deep  cervical  fascia,  which  separates  it  from  the  sterno- 
mastoid  muscle,  and  is  covered  in  by  the  platysma  myoides  and  superfi- 
cial fascia.  At  the  root  of  the  neck  it  pierces  the  deep  cervical  fascia ;  it 
is  accompanied,  for  the  upper  half  of  its  course,  by  the  auricularis  magnus 
nerve.  The  branches  which  it  receives  are  the  occipital  cutaneous  and 
posterior  cervical  cutaneous,  and,  near  its  termination,  the  supra  and  pos- 
terior scapular. 

The  external  jugular  vein  is  very  variable  in  size,  and  is  occasionally 
replaced  by  two  veins.  In  the  parotid  gland  it  receives  a  large  commu- 
nicating branch  from  the  internal  jugular  vein. 

The  Anterior  jugular  vein  is  a  trunk  of  variable  size,  which  collects  the 
blood  from  the  integument  and  superficial  structures  on  the  fore  part  of 
the  neck.  It  passes  downwards  along  the  anterior  border  of  the  sterno- 
mastoid  muscle,  and  opens  into  the  subclavian  vein,  near  the  termination 
of  the  external  jugular.  The  two  veins  communicate  with  each  other, 
and  with  the  external  and  internal  jugular  vein. 

The  Internal  jugular  vein,  formed  by  the  convergence  of  the  lateral  and 
inferior  petrosal  sinus,  commences  at  the  foramen  lacerum  posterius  on 
each  side  of  the  base  of  the  skull,  and  descends  the  side  of  the  neck, 
lying,  in  the  first  instance,  to  the  outer  side  of  the  internal  carotid,  and 
then  upon  the  outer  side  of  the  common  carotid  artery  to  the  root  of  the 
neck,  where  it  unites  with  the  subclavian,  and  constitutes  the  vena  inno- 
minata.  At  its  commencement,  the  internal  jugular  vein  is  posterior  and 
external  to  the  internal  carotid  artery,  and  the  eighth  and  ninth  pairs  of 
nerves  ;  lower  down,  the  vein  and  artery  are  on  the  same  plane,  the  glosso- 
pharyngeal  and  hypoglossal  nerves  passing  forwards  between  them,  the 
pneumogastric  being  between  and  behind  in  the  same  sheath,  and  the 
nervus  accessorius  crossing  obliquely  behind  the  vein. 

The  Branches  which  the  internal  jugular  receives  in  its  course  are,  the 
facial,  the  lingual,  the  inferior  pharyngeal,  the  occipital,  and  the  superior 
and  inferior  thyroid  veins. 

The  Vertebral  vein  descends  by  the  side  of  the  vertebral  artery  in  the 
canal  formed  by  the  foramina  in  the  transverse  processes  of  the  cervical 
29* 


342 


VEINS    OF    THE    UPPER    EXTREMITY. 


vertebrae,  and  terminates  at  the  root  of  the  neck  in  the  commencement  of 
the  vena  innominata.  In  the  lower  part  of  the  vertebral  canal  it  frequently 
divides  into  two  branches,  one  of  which  advances  forwards,  while  the 
other  passes  through  the  foramen  in  the  transverse  process  of  the  seventh 
cervical  vertebra,  before  opening  into  the  vena  innominata. 

The  Branches  which  it  receives  in  its  course  are  the  posterior  condyloid 
vein,  muscular  branches,  the  cervical  meningo-rachidian  veins,  and  near 
its  termination,  the  superficial  and  deep  cervical  veins. 

The  Inferior  thyroid  veins,  two,  and  frequently  more  in  number,  are 
situated  one  on  each  side  of  the  trachea,  and  receive  the  venous  blood 
from  the  thyroid  gland.  They  communicate  with  each  other,  and  with 
the  superior  thyroid  veins,  and  form  a  plexus  upon  the  front  of  the  trachea. . 
The  right  vein  terminates  in  the  right  vena  innominata,  just  at  its  union 
with  the  superior  cava,  and  the  left  in  the  left  vena  innominata. 

VEINS    OF    THE    UPPER    EXTREMITY. 

The  veins  of  the  upper  extremity  are  the  deep  and  superficial.  The 
deep  veins  accompany  the  branches  and  trunks  of  the  arteries,  and  consti- 
tute their  vence  comites.  The  vena3  comites  of  the  radial  and  ulnar  arte- 
ries are  enclosed  in  the  same  sheath  with  those  vessels,  and  terminate  at 
the  bend  of  the  elbow  in  the  brachial  veins.  The  brachial  vena3  comites 
are  situated  one  on  each  side  of  the  artery,  and  open  into  the  axillary 
vein ;  the  axillary  becomes  the  subclavian,  and  the  subclavian  unites  with 
the  internal  jugular  to  form  the  vena  innominata. 

The  Superficial  veins  of  the  fore-arm  are  the — 

Fig.  164.*  Anterior  ulnar  vein, 

Posterior  ulnar  vein, 
Basilic  vein, 
Radial  vein, 
Cephalic  vein, 
Median  vein, 
Median  basilic, 
Median  cephalic. 

The  Anterior  ulnar  vein  collects  the  venous  blood 
from  the  inner  border  of  the  hand,  and  from  the 
vein  of  the  little  finger,  vena  salvatella,  and  ascends 
the  inner  side  of  the  fore-arm  to  the  bend  of  the 
elbow,  where  it  becomes  the  basilic  vein. 

The  Posterior  ulnar  vein,  irregular  in  size,  and 
frequently  absent,  commences  upon  the  inner  bor- 
der and  posterior  aspect  of  the  hand,  and  ascend- 
ing the  fore-arm,  terminates  in  front  of  the  inner 
condyle,  in  the  anterior  ulnar  vein. 

The  Basilic  vein  (/SatfiXixoc:,  royal,  or  principal) 
ascends  from  the  common  ulnar  vein  formed  by  the 
two  preceding,  along  the  inner  side  of  the  upper 
arm,  and  near  its  middle  pierces  the  fascia ;  it  then 
passes  upwards  to  the  axilla,  and  becomes  the  axillary  vein. 

»  The  veins  of  the  fore-arm  and  bend  of  the  elbow.  1.  The  radial  vein.  2  The 
eephaht  vein.  3.  The  anterior  ulnar  vein.  4.  The  posterior  ulnar  vein.  5.  The  trunk 
formed  by  theii  union.  G.  The  basilic  vein,  piercing  the  deep  fascia  at  7.  9.  A  com 


AXILLARY    AND    SUBCLAVIAN    VEINS.  343 

s 

The  Radial  vein  commences  in  the  large  vein  of  the  thumb  on  the 
-auter  and  posterior  aspect  of  the  hand,  and  ascends  along  the  outer  bor- 
der of  the  fore-arm  to  the  bend  of  the  elbow,  where  it  becomes  the  cepha- 
lic vein. 

The  Cephalic  vein  (xspaX--^,  the  head)  ascends  along  the  outer  side  of 
the  arm  to  its  upper  third  ;  it  then  enters  the  groove  between  the  pectora- 
lis  major  arid  deltoid  muscle,  where  it  is  in  relation  with  the  descendino- 
branch  of  the  thoracico-acromialis  artery,  and  terminates  beneath  the  cla- 
vicle in  the  subclavian  vein.  A  large  communicating  branch  sometimes 
crosses  the  clavicle  between  the  external  jugular  and  this  vein,  which 
gives  it  the  appearance  of  being  derived  directly  from  the  head — hence 
its  appellation. 

The  Median  vein  is  intermediate  in  position  between  the  anterior  ulnar 
and  radial  vein ;  it  collects  the  blood  from  the  anterior  aspect  of  the  fore- 
arm, communicating  with  the  two  preceding.  At  the  bend  of  the  elbow 
it  receives  a  branch  from  the  deep  veins,  and  divides  into  two  branches, 
the  median  cephalic  and  median  basilic. 

The  Median  cephalic  vein,  generally  the  smaller  of  the  two,  passes 
obliquely  outwards,  in  the  groove  between  the  biceps  and  supinator  longus, 
to  join  the  cephalic  vein.  The  branches  of  the  external  cutaneous  nerve 
pass  behind  it. 

The  Median  basilic  vein  passes  obliquely  inwards,  in  the  groove  be- 
tween the  biceps  and  pronator  radii  teres,  and  terminates  in  the  basilic 
vein.  This  vein  is  crossed  by  one  or  two  filaments  of  the  internal  cuta- 
neous nerve,  and  is  separated  from  the  brachial  artery  by  the  aponeurotic 
slip  given  off  by  the  tendon  of  the  biceps. 


AXILLARY    VEIN. 

The  axillary  vein  is  formed  by  the  union  of  the  venae  comites  of  the 
brachial  artery  with  the  basilic  vein.  It  lies  in  front  of  the  artery,  receives 
numerous  branches  from  the  collateral  veins  of  the  branches  of  the  axillary 
artery ;  and  at  the  lower  border  of  the  first  rib  becomes  the  subclavian 
vein. 

SUBCLAVIAN    VEIN. 

The  subclavian  vein  crosses  over  the  first  rib  and  beneath  the  clavicle, 
and  unites  with  the  internal  jugular  vein  to  form  the  vena  innominata.  It 
lies  at  first  in  front  of  the  subclavian  artery,  and  then  in  front  of  the  sca- 
lenus  anticus,  which  separates  it  from  that  vessel.  The  phrenic  and 
pneumogastric  nerves  pass  between  the  artery  and  vein.  The  veins  open- 
ing into  the  subclavian  are  the  cephalic  below  the  clavicle,  and  the  external 
and  anterior  jugulars  above;  occasionally  some  small  veins  from  the 
neighbouring  parts  also  terminate  in  it. 

municating  branch  between  the  deep  veins  of  the  fore-arm  and  the  upper  part  of  the 
median  vein.  10.  The  median  cephalic  vein.  11.  The  median  basilic.  12.  A  slight 
convexity  of  the  deep  fascia,  formed  by  the  brachial  artery.  13.  The  process  of  fascia, 
derived  from  the  tendon  of  the  biceps,  which  separates  the  median  basilic  vein  from 
the  brachial  artery.  14.  The  external  cutaneous  nerve,  piercing  the  deep  fascia,  ana 
dividing  into  two  branches,  which  pass  behind  the  median  cephalic  vein.  15.  The  in 
ternal  cutaneous  nerve,  dividing  into  branches,  which  pass  in  front  of  the  median  basi- 
lic vein.  16.  The  intercosto-humeral  cutaneous  nerve.  17.  The  spiral  cutaneous  nerv. 
a  branch  of  the  musculo-spinu. 


344  FEMORAL   VEIN  —  VEINS    OF   THE    TRUNK. 

VEINS     OF     THE     LOWER     EXTREMITY. 

The  veins  of  the  lower  extremity  are  the  deep  and  superficial.  The 
deep  veins  accompany  the  branches  of  the  arteries  in  pairs,  and  form  th« 
venae  comites  of  the  anterior  and  posterior  tibial  and  peroneal  arteries. 
These  veins  unite  in  the  popliteal  region  to  form  a  single  vein  of  large 
size,  the  popliteal,  which  successively  becomes  in  its  course  the  femoral 
and  the  external  iliac  vein. 

POPLITEAL    VEIN. 

The  popliteal  vein  ascends  through  the  popliteal  region,  lying,  in  the 
first  instance,  directly  upon  the  artery,  and  then  getting  somewhat  to  its 
outer  side.  It  receives  several  muscular  and  articular  branches,  and  the 
external  saphenous  vein.  The  valves  in  this  vein  are  four  or  five  in 
number. 

FEMORAL    VEIN. 

The  femoral  vein,  passing  through  the  opening  in  the  adductor  magnus 
muscle,  ascends  the  thigh  in  the  sheath  of  the  femoral  artery,  and  entering 
the  pelvis  beneath  Poupart's  ligament,  becomes  the  external  iliac  vein. 
In  the  lower  part  of  its  course  it  is  situated  upon  the  outer  side  of  the 
artery;  it  then  becomes  placed  behind  that  vessel,  and,  at  Poupart's  liga- 
ment, lies  to  its  inner  side.  It  receives  the  muscular  veins,  and  the  pro- 
runda,  and,  through  the  saphenous  opening,  the  internal  saphenous  vein. 
The  valves  in  this  vein  are  four  or  five  in  number. 

The  Prqfunda  vein  is  formed  by  the  convergence  of  the  numerous  small 
veins  which  accompany  the  branches  of  the  artery  ;  it  is  a  vein  of  large 
size,  lying  in  front  of  the  profunda  artery,  and  it  terminates  in  the  femoral 
at  about  an  inch  and  a  half  below  Poupart's  ligament. 

The  Superficial  veins  are  the  external  or  short,  and  the  internal  or  long 
saphenous. 

The  External  saphenous  vein  collects  the  blood  from  the  outer  side  of 
the  foot  and  leg.  It  passes  behind  the  outer  ankle,  ascends  along  the 
posterior  aspect  of  the  leg,  lying  in  the  groove  between  the  two  bellies  of 
the  gastrocnemius  muscle,  and  pierces  the  deep  fascia  in  the  popliteal 
region  to  join  the  popliteal  vein.  It  receives  several  cutaneous  branches 
in  the  popliteal  region  before  passing  through  the  deep  fascia,  and  is  ac- 
companied in  its  course  by  the  external  saphenous  nerve. 

The  Internal  saphenous  vein  commences  upon  the  dorsum  and  inner 
side  of  the  foot.  It  ascends  in  front  of  the  inner  ankle,  and  along  the 
inner  side  of  the  leg ;  it  then  passes  behind  the  inner  condyle  of  the  femur 
and  along  the  inner  side  of  the  thigh  to  the  saphenous  opening,  where  it 
pierces  the  sheath  of  the  femoral  vessels,  and  terminates  in  the  femoral 
vein,  at  about  one  inch  and  a  half  below  Poupart's  ligament. 

It  receives  in  its  course  the  cutaneous  veins  of  the  leg  and  thigh,  and 
communicates  freely  with  the  deep  veins.  At  the  saphenous  opening  it 
is  joined  by  the  superficial  epigastric  and  circumflexa  ilii  veins,  and  by 
the  external  pudic.  The  situation  of  this  vein  in  the  thigh  is  not  unfre- 
quently  occupied  by  two  or  even  three  trunks  of  nearly  equal  size. 

VEINS    OF    THE    TRUNK. 

The  veins  of  the  trunk  maybe  divided  into,  1.  The  superior  vena  cava, 
with  its  fo-mative  branches.  2.  The  inferior  vena  cava,  with  its  formative 


SUPERIOR   AND    INFERIOR   VEN^E    CAV^E.  345 

branches.     3.  The  azygos  veins.     4.  The  vertebral  and  spinal  veins.     5. 
The  cardiac  veins.     6.  The  portal  vein.     7.  The  pulmonary  veins. 

SUPERIOR     VENA     CAVA,     WITH     ITS     FORMATIVE 
BRANCHES. 

Vence  Innominate. 

The  Vena  Innominate  are  two  large  trunks,  formed  by  the  union  of 
the  internal  jugular  and  subclavian  vein,  at  each  side  of  the  root  of  the 
neck. 

The  Right  vena  innominata,  about  an  inch  and  a  quarter  in  length,  lies 
superficially  and  externally  to  the  arteria  innominata,  and  descends  almost 
vertically  to  unite  with  its  fellow  of  the  opposite  side  in  the  formation  of 
the  superior  cava.  At  the  junction  of  the  jugular  and  subclavian  veins  it 
receives  from  behind  the  ductus  lymphaticus  dexter,  and  lower  down  it 
has  opening  into  it  the  right  vertebral,  right  internal  mammary,  and  right 
inferior  thyroid  vein. 

The  Left  vena  innominata,  considerably  longer  than  the  right,  extends 
almost  horizontally  across  the  roots  of  the  three  great  arteries  arising  from 
the  arch  of  the  aorta,  to  the  right  side  of  the  mediastinum,  where  it  unites 
with  the  right  vena  innominata,  to  constitute  the  superior  cava. 

It  is  in  relation  in  front  with  the  left  sterno-clavicular  articulation  and 
the  first  piece  of  the  sternum.  At  its  commencement  it  receives  the  tho- 
racic duct  which  opens  into  it  from  behind,  and  in  its  course  is  joined  by 
the  left  vertebral,  left  inferior  thyroid,  left  mammary,  and  by  the  superior 
intercostal  vein.  It  also  receives  some  small  veins  from  the  mediastinum 
and  thymus  gland.  There  are  no  valves  in  the  venae  innominatae. 

SUPERIOR    VENA    CAVA. 

The  superior  cava  is  a  short  trunk  about  three  inches  in  length,  formed 
by  the  junction  of  the  two  venae  innominatse.  It  descends  perpendicularly 
on  the  right  side  of  the  mediastinum,  and  entering  the  pericardium  termi- 
nates in  the  upper  part  of  the  right  auricle. 

It  is  in  relation  in  front  with  the  thoracic  fascia,  which  separates  it  from 
the  thymus  gland,  and  with  the  pericardium  ;  behind  with  the  right  pulmo- 
nary artery,  and  right  superior  pulmonary  vein ;  internally  with  the  ascend- 
ing aorta ;  externally  with  the  right  phrenic  nerve,  and  right  lung.  Im- 
mediately before  entering  the  pericardium  it  receives  the  vena  azygos 
major. 

INFERIOR    VENA    CAVA,    WITH    ITS    FORMATIVE 
BRANCHES. 

Eiac  Veins. 

The  External  iliac  vein  lies  to  the  inner  side  of  the  corresponding  artery 
at  the  os  pubis ;  but  gradually  gets  behind  it  as  it  passes  upwards  along 
the  brim  of  the  pelvis,  and  it  terminates  opposite  the  sacro-iliac  symphysis 
by  uniting  with  the  internal  iliac,  to  form  the  common  iliac  vein.  Imme- 
diately above  Poupart's  ligament  it  receives  the  epigastric  and  circumflexa 
ilii  veins ;  it  has  no  valves. 


346 


INFERIOR   VENA    CAVA. 


Fig.  165.*  The  Internal  iliac  vein  is  formed  by  vessels 

which  correspond  with  the  branches  of  the  in- 
ternal iliac  artery;  it  receives  the  returning 
blood  from  the  gluteal,  ischiatic,  internal  pudic, 
and  obturator  veins,  externally  to  the  pelvis ; 
and  from  the  vesical  and  uterine  plexuses 
within  the  pelvis.  The  vein  lies  to  the  inner 
side  of  the  internal  iliac  artery,  and  terminates 
by  uniting  with  the  external  iliac  vein,  to  form 
the  common  iliac. 

The  Vesical  and  prostatic  plexus  is  an  im- 
portant plexus  of  veins  which  surrounds  the 
neck  and  base  of  the  bladder  and  prostate 
gland,  and  receives  its  blood  from  the  great 
dorsal  vein  of  the  penis,  and  from  the  veins  of 
the  external  organs  of  generation.  It  is  retain- 
ed in  connection  with  the  sides  of  the  bladder 
by  a  reflexion  of  the  pelvic  fascia. 

The  Uterine  plexus  is  situated  around  the 
vagina,  and  upon  the  sides  of  the  uterus,  be- 
tween the  two  layers  of  the  broad  ligaments. 
The  veins  forming  the  vesical  and  uterine 
plexus  are  peculiarly  subject  to  the  production 
of  phlebolites. 

The  Common  iliac  veins  are  formed  by  the 
union  of  the  external  and  internal  iliac  vein 
on  each  side  of  the  pelvis.  The  right  com- 
mon iliac,  shorter  than  the  left,  ascends  ob- 
liquely behind  the  corresponding  artery ;  and 
upon  the  intervertebral  substance  between  the 
fourth  and  fifth  lumbar  vertebrae,  unites  with 
the  vein  of  the  opposite  side,  to  form  the  inferior  cava.  The  left  common 
iliac,  longer  and  more  oblique  than  the  right,  ascends  behind,  and  a  little 
internally  to  the  corresponding  artery,  and  passes  beneath  the  right  com- 
mon iliac  artery,  near  its  origin,  to  unite  with  the  right  vein  in  the  forma- 
tion of  the  inferior  vena  cava.  The  right  common  iliac  vein  has  no  branch 
opening  into  it ;  the  left  receives  the  vena  sacra  media.  These  veins  have 
no  valves. 

INFERIOR    VENA    CAVA. 

The  inferior  vena  cava  is  formed  by  the  union  of  the  two  common  iliac 
veins,  upon  the  intervertebral  substance  between  the  fourth  and  fifth  Jam- 

*  The  veins  of  the  trunk  and  neck.  1.  The  superior  vena  cava.  2.  The  left  vena 
innominata.  3.  The  right  vena  innominata.  4.  The  right  subclavian  vein.  5.  The 
internal  jugular  vein.  6.  The  external  jugular.  7.  The  anterior  jugular.  8.  The  infe- 
rior vena  cava.  9.  The  external  iliac  vein.  10.  The  internal  iliac  vein.  11.  The  com- 
mon iliac  veins;  the  small  vein  between  these  is  the  vena  sacra  media.  12,  12.  Lum- 
bar veins.  13.  The  right  spermatic  vein.  14.  The  left  spermatic,  opening  into  the  left 
renal  vein.  15.  The  right  renal  vein.  16.  The  trunk  of  the  hepatic  veins.  17.  The 
greater  vena  azygos,  commencing  interiorly  in  the  lumbar  veins.  18.  The  lesser  v^ena 
azygos,  also  commencing  in  the  lumbar  veins.  19.  A  branch  of  communication  with 
the  left  renal  vein.  20.  The  termination  of  the  lesser  in  the  greater  vena  azygos.  21. 
The  superior  intercostal  vein;  communicating  inferiorly  with  the  lesser  vena  azygos, 
wid  terminating  superiorly  in  the  left  vena  innominata. 


INFERIOR   VENA    CAVA.  347 

bar  vertebra.  It  ascends  along  the  front  of  the  vertebral  column,  on  the 
right  side  of  the  abdominal  aorta,  and  passing  through  the  fissure  in  the 
posterior  border  of  the  liver  and  the  quadrilateral  opening  in  the  tendinous 
centre  of  the  diaphragm,  terminates  in  the  inferior  and  posterior  part  of 
the  right  auricle.  There  are  no  valves  in  this  vein. 

It  is  in  relation  from  below  upwards,  in  front  with  the  mesentery,trans- 
verse  duodenum,  portal  vein,  pancreas,  and  liver,  which  latter  nearly  and 
sometimes  completely  surrounds  it ;  behind  it  rests  on  the  vertebral  column 
and  right  crus  of  the  diaphragm,  from  which  it  is  separated  by  the  right 
renal  and  right  lumbar  arteries ;  to  the  right  it  has  the  peritoneum  and 
sympathetic  nerve ;  and  to  the  left  the  aorta. 

The  Branches  which  the  inferior  cava  receives  in  its  course,  are  the—- 
Lumbar, 
Right  spermatic, 
Renal, 
Supra-renal, 
Phrenic, 
Hepatic. 

The  Lumbar  veins,  three  or  four  in  number  on  each  side,  collect  the 
venous  blood  from  the  muscles  and  integument  of  the  loins,  and  from  the 
spinal  veins :  the  left  are  longer  than  the  right  on  account  of  the  position 
of  the  vena  cava. 

The  Right  spermatic  vein  is  formed  by  the  two  veins  which  return  the 
blood  from  the  venous  plexus  situated  in  the  spermatic  cord.  These  veins 
follow  the  course  of  the  spermatic  artery,  and  unite  to  form  the  single  trunk 
which  opens  into  the  inferior  vena  cava.  The  left  spermatic  vein  terminates 
in  the  left  renal  vein. 

The  Ovarian  veins  represent  the  spermatic  veins  of  the  male,  and  collect 
the  venous  blood  from  the  ovaries,  round  ligaments,  and  Fallopian  tubes, 
and  communicate  with  the  uterine  sinuses.  They  terminate  as  in  the 
male. 

The  Renal  or  emulgent  veins  return  the  blood  from  the  kidneys ;  their 
branches  are  situated  in  front  of  the  divisions  of  the  renal  arteries,  and  the 
left  opens  into  the  vena  cava  somewhat  higher  than  the  right.  The  left 
is  longer  than  the  right  in  consequence  of  the  position  of  the  vena  cava, 
and  crosses  the  aorta  immediately  below  the  origin  of  the  superior  mesen- 
teric  artery.  It  receives  the  left  spermatic  vein,  which  terminates  in  it  at 
right  angles :  hence  the  more  frequent  occurrence  of  varicocele  on  the  left 
than  on  the  right  side. 

The  Supra-renal  veins  terminate  partly  in  the  renal  veins,  and  partly  in 
the  inferior  vena  cava. 

The  Phrenic  veins  return  the  blood  from  the  ramifications  of  the  phrenic 
arteries  ;  they  open  into  the  inferior  cava. 

The  Hepatic  veins  form  two  principal  trunks  and  numerous  smaller  veins 
which  open  into  the  inferior  cava,  while  that  vessel  is  situated  in  the  pos- 
terior border  of  the  liver.  The  hepatic  veins  commence  in  the  liver  by 
minute  venules,  the  intralobular  veins,  in  the  centre  of  each  lobule  ;  these 
pour  their  blood  into  larger  vessels,  the  sublobular  veins ;  and  the  sublo- 
bular  veins  constitute,  by  their  convergence  and  union,  the  hepatic  trunks, 
which  terminate  in  the  inferior  vena  cava. 


348  VERTEBRAL    AND    SPINAL   VEINS. 

AZYGOS    VEINS. 

The  azygos  veins  (fig.  165)  form  a  system  of  communication  between 
the  superior  and  inferior  vena  cava,  and  serve  to  return  the  blood  from 
that  part  of  the  trunk  of  the  body  in  which  those  vessels  are  deficient,  on 
account  of  their  connexion  with  the  heart.  This  system  consists  of  three 
vesselsj  the 

Vena  azygos  major, 

Vena  azygos  minor, 

Superior  intercostal  vein. 

The  Vena  azygos  major  commences  in  the  lumbar  region  by  a  commu- 
nication with  the  lumbar  veins ;  sometimes  it  is  joined  by  a  branch  directly 
from  the  inferior  vena  cava,  or  by  one  from  the  renal  vein.  It  passes 
through  the  aortic  opening  in  the  diaphragm,  and  ascends  along  the  right 
side  of  the  vertebral  column  to  the  third  dorsal  vertebra,  where  it  arches 
forwards  over  the  right  bronchus,  and  terminates  in  the  superior  cava.  It 
receives  all  the  intercostal  veins  of  the  right  side,  the  vena  azygos  minor, 
and  the  bronchial  veins. 

The  Vena  azygos  minor  commences  in  the  lumbar  region,  on  the  left 
side,  by  a  communication  with  the  lumbar  or  renal  veins.  It  passes  be- 
aeath  the  border  of  the  diaphragm,  and,  ascending  along  the  left  side  of 
the  vertebral  column,  crosses  the  fifth  or  sixth  dorsal  vertebra  to  open  into 
the  vena  azygos  major.  It  receives  the  six  or  seven  lower  intercostal 
veins  of  the  left  side.  The  azygos  veins  have  no  valves. 

The  Superior  intercostal  vein  is  the  trunk  formed  by  the  union  of  the  five 
or  six  upper  intercostal  veins  of  the  left  side.  It  communicates  below  with 
the  vena  azygos  minor,  and  ascends  to  terminate  in  the  left  vena  innominata. 

VERTEBRAL    AND     SPINAL    VEINS. 

The  numerous  venous  plexuses  of  the  vertebral  column  and  spinal  cord 
may  be  arranged  into  three  groups : — 

Dorsi-spinal, 

Meningo-rachidian, 

Medulli-spinal, 

The  Dorsi-spinal  veins  form  a  plexus  around  the  spinous,  transverse  and 
urticular  processes,  and  arches  of  the  vertebrae.  They  receive  the  return- 
»ng  blood  from  the  dorsal  muscles  and  surrounding  structures,  and  trans- 
wilt  it,  in  part  to  the  meningo-rachidian,  and  in  part  to  the  vertebral,  in- 
tercostal, lumbar,  and  sacral  veins. 

The  Meningo-rachidian  veins  are  situated  between  the  theca  vertebralis 
and  the  vertebrae.  They  communicate  freely  with  each  other  by  means 
of  a  complicated  plexus.  In  front  they  form  two  longitudinal  trunks, 
(longitudinal  spinal  sinuses,}  which  extend  the  whole  length  of  the  column 
on  each  side  of  the  posterior  common  ligament,  and  are  joined  on  the 
bor"y  of  each  vertebra  by  transverse  trunks,  which  pass  beneath  the  liga- 
ment, and  receive  the  large  basi-vertebral  veins  from  the  interior  of  each 
vertebra.  The  meningo-rachidian  veins  communicate  superiorly  through 
the  anterior  condyloid  foramina  with  the  internal  jugulars ;  in  the  neck 
they  pour  their  blood  into  the  vertebral  veins;  in  the  thorax,  into  the  in- 


PORTAL    SYSTEM.  349 

tercostals ;  and  in  the  loins  and  pelvis  into  the  lumbar  and  sacral  veins, 
the  communications  being  established  through  the  intervertebral  foramina. 
The  Medulli-spinal  veins  are  situated  between  the  pia  mater  and  arach- 
noid ;  they  communicate  freely  with  each  other  to  form  plexuses,  and  they 
send  branches  through  the  intervertebral  foramina  with  each  of  the  spinal 
nerves,  to  join  the  veins  of  the  trunk. 

CARDIAC    VEINS. 

The  veins  returning  the  blood  from  the  substance  of  the  heart,  are  the — 

Great  cardiac  vein, 
Posterior  cardiac  veins, 
Anterior  cardiac  veins, 
Venae  Thebesii. 

The  Great  cardiac  vein  (coronary)  commences  at  the  apex  of  the  heart, 
and  ascends  along  the  anterior  ventricular  groove  to  the  base  of  the  ven- 
tricles ;  it  then  curves  around  the  left  auriculo-ventricular  groove  to  the 
posterior  part  of  the  heart,  where  it  terminates  in  the  right  auricle.  It  re- 
ceives in  its  course  the  left  cardiac  veins  from  the  left  auricle  and  ventricle, 
and  the  posterior  cardiac  veins  from  the  posterior  ventricular  groove. 

The  Posterior  cardiac  vein,  frequently  two  in  number,  commences  also 
at  the  apex  of  the  heart,  and  ascends  along  the  posterior  ventricular  groove, 
to  terminate  in  the  great  cardiac  vein.  It  receives  the  veins  from  the  pos- 
terior aspect  of  the  two  ventricles. 

The  interior  cardiac  veins  collect  the  blood  from  the  anterior  surface 
of  the  right  ventricle  ;  one  larger  than  the  rest  runs  along  the  right  border 
of  the  heart  and  joins  the  trunk  formed  by  these  veins,  which  curves  around 
the  right  auriculo-ventricular  groove,  to  terminate  in  the  great  cardiac  vein 
near  its  entrance  into  the  right  auricle. 

The  Vena  Thebesii  are  numerous  minute  venules  which  convey  the 
venous  blood  directly  from  the  substance  of  the  heart  into  its  four  cavities. 
Then*  existence  is  denied  by  some  anatomists. 

PORTAL    SYSTEM. 

The  portal  system  is  composed  of  four  large  veins  which  return  the 
blood  from  the  chylopoietic  viscera;  they  are  the — 

Inferior  mesenteric  vein, 
Superior  mesenteric  vein, 
Splenic  vein, 
Gastric  veins. 

The  Inferior  mesenteric  vein  receives  its  blood  from  the  rectum  by 
means  of  the  haemorrhoidal  veins,  and  from  the  sigmoid  flexure  and  de 
scending  colon,  and  ascends  behind  the  transverse  duodenum  and  pan 
creas,  to  terminate  in  the  splenic  vein.  Its  haemorrhoidal  branches  inos 
culate  with  branches  of  the  internal  iliac  vein,  and  thus  establish  a  com 
munication  between  the  portal  and  general  venous  system. 

The  Superior  mesenteric  vein  is  formed  by  branches  which  collect  the 
venous  blood  from  the  capillaries  of  the  superior  mesenteric  artery ;  they 
30 


350  VENA    PORT.E. 

constitute  by  their  junction  a  large  trunk,  which  ascends  by  the  side  of  the 
corresponding  artery,  crosses  the  transverse  duodenum,  and  unites  behind 
the  pancreas  with  the  splenic  in  the  formation  of  the  portal  vein. 

The  Splenic  vein  commences  in  the  structure  of  the  spleen,  and  quits 
that  organ  by  several  large  veins :  it  is  larger  than  the  splenic  artery,  and 

Fig.  166.» 


perfectly  straight  in  its  course.  It  passes  horizontally  inwards  behind  the 
pancreas,  and  terminates  near  its  greater  end  by  uniting  with  the  superior 
mesenteric,  and  forming  the  portal  vein.  It  receives  in  its  course  the 
gastric  and  pancreatic  veins,  and  near  its  termination  the  inferior  mesen- 
teric vein. 

The  Gastric  veins  correspond  with  the  gastric,  gastro-epiploic,  and 
vasa  brevia  arteries,  and  terminate  in  the  splenic  vein. 

The  VENA  PORTVE,  formed  by  the  union  of  the  splenic  and  superior 
mesenteric  vein  behind  the  pancreas,  ascends  through  the  right  border  of 
the  lesser  omentum  to  the  transverse  fissure  of  the  liver,  where  it  divides 
into  two  branches,  one  for  each  lateral  lobe.  In  the  right  border  of  the 
lesser  omentum  it  is  situated  behind  and  between  the  hepatic  artery  and 
ductus  communis  choledochus,  and  is  surrounded  by  the  hepatic  plexus 
of  nerves  and  lymphatics.  At  the  transverse  fissure  each  primary  branch 
divides  into  numerous  secondary  branches,  which  ramify  through  the 

*  The  portal  vein.  1.  The  inferior  mesenteric  vein  ;  it  is  traced  by  means  of  dotted 
.ines  behind  the  pancreas  (2)  to  terminate  in  the  splenic  vein  (3).  4.  The  spleen.  5. 
tjastric  veins,  opening  into  the  splenic  vein.  6.  The  superior  mesenteric  vein.  7.  The 
descending  portion  of  the  duodenum.  8.  Its  transverse  portion,  which  is  crossed  by  the 
superior  mesenteric  vein  and  by  a  part  of  the  trunk  of  the  superior  mesenteric  artery. 
9  The  portal  vein.  10.  The  hepatic  artery.  11.  The  ductus  communis  choledochus. 
12.  The  division  of  the  duct  and  vessels  at  the  transverse  fissure  of  the  liver.  13.  The 
eystic  duct  leading  to  the  gall  bladder. 


ON    THE    LYMPHATICS.  351 

portal  canals,  and  give  off  vaginal  and  interlobular  veins,  and  the  latter 
terminate  in  the  lobular  venous  plexus  of  the  lobules  of  the  liver.  The 
portal  vein  within  the  liver  receives  the  venous  blood  from  the  capillaries 
of  the  hepatic  artery. 

PULMONARY    VEINS. 

The  pulmonary  veins,  four  in  number,  return  the  arterial  blood  from 
the  lungs  to  the  left  auricle  of  the  heart ;  they  differ  from  the  veins  in 
general,  in  the  area  of  their  cylinders  being  very  little  larger  than  that  of 
the  corresponding  arteries,  and  in  accompanying  singly  each  branch  of  the 
pulmonary  artery.  They  commence  in  the  capillaries  upon  the  parietes 
of  the  intercellular  passages  and  air-cells,  and  unite  to  form  a  single  trunk 
for  each  lobe.  The  vein  of  the  middle  lobe  of  the  right  lung  unites  with 
the  superior  vein,  so  as  to  form  the  two  trunks  which  open  into  the  left 
auricle.  Sometimes  they  remain  separate,  and  then  there  are  three  pul- 
monary veins  on  the  right  side.  The  right  pulmonary  veins  pass  behind 
the  superior  vena  cava  to  the  left  auricle,  and  the  left  behind  the  pulmo- 
nary artery;  they  both  pierce  the  pericardium.  Within  the  lung  the 
branches  of  the  pulmonary  veins  are  behind  the  bronchial  tubes,  and  those 
of  the  pulmonary  artery  in  front ;  but  at  the  root  of  the  lungs  the  veins  are 
in  front,  next  the  arteries,  and  then  the  bronchi.  There  are  no  valves  in 
the  pulmonary  veins. 


CHAPTER  VIII. 

ON  THE  LYMPHATICS. 

THE  lymphatic  vessels,  or  absorbents,  have  received  their  double  appel- 
lation from  certain  phenomena  which  they  present ;  the  former  name  being 
derivable  from  the  appearance  of  the  limpid  fluid  (lympha,  water)  which 
they  convey ;  and  the  latter  from  their  supposed  property  of  absorbing 
foreign  substances  into  the  system.  They  are  minute,  delicate,  and  trans- 
parent vessels,  remarkable  for  their  general  uniformity  of  size,  for  a  knotted 
appearance  which  is  due  to  the  presence  of  numerous  valves,  for  the  fre- 
quent dichotomous  divisions  which  occur  in  their  course,  and  for  their 
division  into  several  branches  immediately  before  entering  a  gland.  Their 
office  is  to  collect  the  products  of  digestion  and  the  detrita  of  nutrition, 
and  convey  them  into  the  venous  circulation  near  the  heart. 

Lymphatic  vessels  commence  in  a  delicate  network  which  is  distributed 
on  the  cutaneous  surface  of  the  body,  on  the  various  surfaces  of  organs 
and  throughout  their  internal  structure  ;  and  from  this  network  the  lym- 
phatic vessels  proceed,  nearly  in  straight  lines,  in  a  direction  towards  the 
root  of  the  neck.  In  their  course  they  are  intercepted  by  numerous  small, 
spheroid,  or  oblong,  or  flattened  bodies,  lymphatic  glands.  The  lymphatic 
vessels  entering  these  glands  are  termed  vasa  inferentia  or  qfferentia,  and 
those  which  quit  them,  vasa  efferentia.  The  vasa  inferentia  vary  in  num. 
ber  from  two  to  six,  they  divide  at  the  distance  of  a  few  lines  from  the 
gland  into  several  smaller  vessels,  and  enter  it  by  one  of  the  flattened  sur- 


352  GENERAL    ANATOMY    OF    LYMPHATICS. 

faces.*  The  vasa  efferentia  escape  from  the  gland  on  the  opposite,  but 
not  unfrequently  on  the  same  surface  ;  they  consist,  like  the  vasa  inferentia 
at  their  junction  with  the  gland,  of  several  small  vessels  which  unite  after 
a  course  of  a  few  lines  to  form  from  one  to  three  trunks,  often  twice  as 
large  as  the  vasa  inferentia. 

Lymphatic  vessels  admit  of  a  threefold  division,  into  superficial,  deep, 
and  lacteals.  The  superficial  lymphatic  vessels,' on  the  surface  of  the 
body,  follow  the  course  of  the  veins,  and  pierce  the  deep  fascia  in  conve- 
nient situations,  to  join  the  deep  lymphatics  On  the  surface  of  organs 
they  converge  to  the  nearest  lymphatic  trunks.  The  superficial  lymphatic 
glands  are  placed  in  the  most  protected  situations  of  the  superficial  fascia, 
as  in  the  hollow  of  the  ham  and  groin  in  the  lower  extremity,  and  on  the 
inner  side  of  the  arm  in  the  upper  extremity. 

The  deep  lymphatics,  fewer  in  number  and  somewhat  larger  than  the 
superficial  vessels,  accompany  the  defeper  veins ;  those  from  the  lower 
parts  of  the  body  converging  to  the  numerous  glands  seated  around  the 
iliac  veins  and  inferior  vena  cava,  and  terminating  in  a  large  trunk  situated 
on  the  vertebral  column,  the  thoracic  duct.  From  the  upper  part  of  the 
trunk  of  the  body  on  the  left  side,  and  from  the  left  side  of  the  head  and 
neck,  they  also  proceed  to  the  thoracic  duct.  Those  on  the  right  side  of 
the  head  and  neck,  right  upper  extremity,  and  right  side  of  the  thorax, 
form  a  distinct  duct  which  terminates  at  the  point  of  junction  of  the  sub- 
clavian  with  the  internal  jugular  vein  on  the  right  side  of  the  root  of  the 
neck. 

The  lacteals  are  the  lymphatic  vessels  of  the  small  intestines ;  they  have 
received  their  distinctive  appellation  from  conveying  the  milk-like  product 
of  digestion,  the  chyle,  to  the  great  centre  of  the  lymphatic  system,  the 
thoracic  duct.  They  are  situated  in  the  mesentery,  and  pass  through  the 
numerous  mesenteric  glands  in  their  course. 

Lymphatic  vessels  are  very  generally  distributed  through  the  animal 
tissues ;  there  are,  nevertheless,  certain  structures  in  which  they  have 
never  been  detected ;  for  example,  the  brain  and  spinal  cord,  the  eye, 
bones,  cartilages,  tendons,  the  membranes  of  the  ovum,  the  umbilical 
cord,  and  the  placenta.  The  anastomoses  between  these  vessels  are  less 
frequent  than  between  arteries  and  veins ;  they  are  effected  by  means  of 
vessels  of  equal  size  with  the  vessels  which  they  connect,  and  no  increase 
of  calibre  results  from  their  junction.  The  lymphatic  vessels  are  smallest 
in  the  neck,  larger  in  the  upper  extremities,  and  larger  still  in  the  lower 
limbs. 

For  the  purpose  of  effecting  the  movement  of  their  fluids  in  a  proper 
direction,  lymphatic  vessels  are  furnished  with  valves,  and  it  is  to  these 
that  the  appearance  of  constrictions  around  the  cylinders  of  the  vessels,  at 
short  distances,  is  due.  Like  the  valves  of  veins,  the  valves  of  lymphatic 
vessels  are  each  composed  of  two  semilunar  flaps  attached  by  their  convex 
oorder  to  the  sides  of  the  vessel  and  free  by  their  concave  border.  This 
is  the  general  character  of  the  valves,  but,  as  in  veins,  there  are  exceptions 
in  their  form  and  disposition ;  sometimes  one  flap  is  so  small  as  to  be 
merely  rudimentary,  while  the  other  is  large  in  proportion  ;  sometimes 
the  flap  runs  all  the  way  round  the  tube,  leaving  a  central  aperture  which 
can  only  be  closed  by  a  contractile  power  in  the  valve  itself;  and  some- 

^ee  Mr.  Lane's  article  on  the  "Lymphatic  System,"  in  the  Cyclopaedia  of  Anatomy 
ar,n  Physiology. 


LYMPHATICS  OF  THE  HEAD  AND  NECK.         353 

times  instead  of  being  circular  the  aperture  is  elliptical,  and  the  arran^e- 
ment  of  the  flaps  like  that  of  the  ileo-coecal  valve.*  These  peculiarities 
are  most  frequently  met  with  at  and  near  the  anastomoses  of  the  lymphatic 
vessels.  The  valves  occur  most  numerously  near  the  lymphatic  ^lands ; 
next  in  frequency  they  are  found  in  the  neck  and  upper  extremities^  where 
the  vessels  are  small,  and  least  numerously  in  the  lower  limbs,  where  the 
lymphatics  are  larger.  In  the  thoracic  duct  an  interspace  of  two  or  three 
inches  frequently  occurs  between  the  valves.  Connected  with  the  presence 
of  valves  in  the  lymphatic  vessels,  are  two  lateral  dilatations  or  pouches, 
analogous  to  the  valvular  sinuses  of  veins.  These  sinuses  are  situated  on 
the  cardiac  side  of  the  valves ;  they  receive  the  valves  when  the  latter  are 
thrown  back  by  the  current  of  the  lymph ;  and  when  reflux  occurs,  they 
become  distended  with  a  body  of  fluid  which  makes  pressure  on  the  flaps. 
These  pouch-like  dilatations  and  the  constrictions  corresponding  with  the 
line  of  attachment  of  the  convex  borders  of  the  flaps  are  the  cause  of  the 
knotted  appearance  of  distended  lymphatic  vessels. 

Like  arteries  and  veins,  lymphatic  vessels  are  composed  of  three  coats, 
external,  middle,  and  internal.  The  external  coat  is  areolo-fibrous,  like 
that  of  blood-vessels ;  it  is  thin,  but  very  strong,  and  serves  to  connect 
the  vessel  to  surrounding  tissues,  at  the  same  time  that  it  forms  a  protec- 
tive covering.  The  middle  coat  is  thin  and  elastic,  and  consists  of  a  layer 
of  longitudinal  fibres  analogous  to  those  of  the  innermost  layer  of  the 
middle  coat  of  arteries  and  veins.  Some  few  circular  fibres  may  be  seen 
externally  to  these  in  the  larger  Jymphatic  vessels.  The  internal  coat  is 
inelastic  and  more  liable  to  rupture  than  the  other  coats.  It  is  a  serous 
layer  continuous  with  the  lining  membrane  of  the  veins,  and  invested  by 
an  epithelium.  The  valves  are  composed  of  a  very  thin  layer  of  fibrous 
tissue,  coated  on  its  two  surfaces  by  epithelium. 

The  lymphatic  glands  (conglobate,  absorbent)  are  small  oval  and  some- 
what flattened  or  rounded  bodies,  composed  of  a  plexus  of  minute  lym- 
phatic vessels,  associated  with  a  plexus  of  blood-vessels,  and  enclosed  in 
a  thin  capsule  of  areolar  tissue.  When  examined  on  the  surface,  they 
are  seen  to  have  a  lobulated  appearance,  while  the  face  of  a  section  is 
cellular,  from  the  division  of  the  numberless  convolutions  which  are  formed 
by  the  lymphatic  vessel* wimin  its  substance.  The  colour  of  the  glands 
is  a  pale  pink,  excepting  those  of  the  lungs,  the  bronchial  glands,  which  in 
the  adult  are  more  or  less  mottled  with  black,  and  are  sometimes  filled 
with  a  black  pigment.  Lymphatic  glands  are  larger  in  the  young  subject 
than  in  the  adult,  and  are  smallest  in  old  age  ;  they,  as  well  as  their  ves- 
sels, are  supplied  with  arteries,  veins  and  nerves,  like  other  structures. 

I  shall  describe  the  lymphatic  vessels  and  glands  according  to  the 
arrangement  adopted  for  the  veins,  commencing  with  those  of  the  head 
and  neck,  and  proceeding  next  to  those  of  the  upper  extremity,  lower  ex- 
tremity, and  trunk, 

LYMPHATICS  OF  THE  HEAD  AND  NECK. 

The  Superficial  lymphatic  glands  of  the  head  and  face  are  small,  few  in 
number,  and  isolated ;  they  are,  the  occipital,  which  are  situated  near  the 
origin  of  the  occipito-frontalis  muscle;  posterior  auricular,  behind  the 
ear ;  parotid,  in  the  parotid  gland ;  zygomatic,  in  the  zygomatic  fossa , 

»  Mr.  Lane,  loc.  cit. 

30*  x 


354        LYMPHATICS  OF  THE  UPPER  EXTREMITY. 

buccal,  upon  the  buccinator  muscle ;  and  submaxillary,  beneath  the  mar- 
gin of  the  lower  jaw.  There  are  no  deep  lymphatic  glands  within  the 
cranium. 

The  Superficial  cervical  lymphatic  glands  are  few  in  number  and  small ; 
they  are  situated  in  the  course  of  the  external  jugular  vein,  between  the 
sterno-mastoid  and  trapezius  muscles,  at  the  root  of  the  neck,  and  about 
the  larynx. 

The  Deep  cervical  glands  (glandulse  concatenate)  are  numerous  and  of 
large  size ;  they  are  situated  around  the  internal  jugular  vein  and  sheath 
of  the  carotid  arteries,  by  the  side  of  the  pharynx,  oesophagus,  and  trachea, 
and  extend  from  the  base  of  the  skull  to  the  root  of  the  neck,  where  they 
are  in  communication  with  the  lymphatic  vessels  and  glands  of  the  thorax. 

The  Superficial  lymphatic  vessels  of  the  head  and  face  are  disposed  in 
three  groups ;  occipital,  which  take  the  course  of  the  occipital  vein  to  the 
occipital  and  deep  cervical  glands ;  temporal,  which  follow  the  branches 
of  the  temporal  vein  to  the  parotid  and  deep  cervical  glands ;  and  facial, 
which  accompany  the  facial  vein  to  the  submaxillary  lymphatic  glands. 

The  Deep  lymphatic  vessels  of  the  head  are  the  meningeal  and  cerebral , 
Jhe  former  are  situated  in  connexion  with  the  meningeal  veins,  and  escape 
through  foramina  at  the  base  of  the  skull,  to  join  the  deep  cervical  glands. 
The  cerebral  lymphatics,  according  to  Fohmann,  are  situated  on  the  sur- 
face of  the  pia  mater,  none  having  as  yet  been  discovered  in  the  substance 
of  the  brain.  They  pass  most  probably  through  the  foramina  at  the  base 
of  the  skull,  to  terminate  in  the  deep  cervical  glands. 

The  Deep  lymphatic  vessels  of  tJie  face  proceed  from  the  nasal  fossa?, 
mouth,  and  pharynx,  and  terminate  in  the  submaxillary  and  deep  cervical 
glands. 

The  Superficial  and  deep  cervical  lymphatic  vessels  accompany  the 
jugular  veins,  passing  from  gland  to  gland,  and  at  the  root  of  the  neck 
communicate  with  the  thoracic  lymphatic  vessels,  and  terminate,  on  the 
right  side,  in  the  ductus  lymphaticus  dexter,  and,  on  the  left,  in  the  tho- 
racic duct,  near  its  termination. 

LYMPHATICS  OF  THE  UPPER  EXTREMITY. 

The  uperficial  lymphatic  glands  of  the  arm  are  not  more  than  four  or 
five  in  number,  and  of  very  small  size.  One  or  two  are  situated  near  the 
median  basilic  and  cephalic  veins,  at  the  bend  of  the  elbow ;  and  one  or 
two  near  the  basilic  vein,  on  the  inner  side  of  the  upper  arm,  immediately 
above  the  elbow. 

The  Deep  glands  in  the  fore-arm  are  excessively  small  and  infrequent ; 
two  or  three  may  generally  be  found  in  the  course  of  the  radial  and  ulnar 
vessels.  In  the  upper  arm  there  is  a  chain  of  small  glands,  accompanying 
the  brachial  artery. 

The  Axillary  glands  are  numerous  and  of  large  size.  Some  are  closely 
adherent  to  the  vessels,  others  are  dispersed  in  the  loose  areolar  tissue  of 
the  axilla,  and  a  small  chain  may  be  observed  extending  along  the  lower 
border  of  the  pectoralis  major  to  the  mammary  gland.  Two  or  three  sub- 
clavian  glands  are  situated  beneath  the  clavicle,  and  serve  as  the  medium 
of  communication  between  the  axillary  and  deep  cervical  lymphatic  glands. 

The  Superficial  lymphatic  vessels  of  the  upper  extremity  commence  upon 
Ihe  fingers  and  take  their  course  along  the  fore-arm  to  the  bend  of  the 


LYMPHATICS    OF   THE    LOWER   EXTREMITY.  355 

elbow.  The  greater  part  reach  their  destination  by  passing  along  the  dorsa« 
surface  of  the  fingers,  wrist,  and  fore-arm,  and  then  curving  around  the 
borders  of  the  latter ;  but  some  few  are  met  with  in  the  palm  of  the  hand 
which  take  the  direction  of  the  median  vein.  At  the  bend  of  the  elbow 
the  lymphatics  arrange  themselves  into  two  groups ;  an  internal  and  larger 
group,  which  communicates  with  a  gland  situated  just  above  the  inner 
condyle,  and  then  accompanies  the  basilic  vein  upwards  to  the  axilla  to 
enter  the  axillary  glands ;  and  a  small  group  which  follows  the  course  of 
the  cephalic  vein.  Several  of  the  vessels  of  this  group  cross  the  biceps 
muscle  at  its  upper  part  to  enter  the  axillary  glands,  while  the  remainder, 
two  or  three  in  number,  ascend  with  the  cephalic  vein  in  the  interspace  of 
the  deltoid  and  pectoralis  major ;  these  latter  usually  join  a  small  gland  in 
this  space,  and  then  cross  the  pectoralis  minor  muscle  to  become  continu- 
ous with  the  subciavian  lymphatics. 

Besides  the  lymphatic  vessels  of  the  arm,  the  axillary  glands  receive 
those  from  the  integument  of  the  chest,  its  anterior,  posterior,  and  lateral 
aspect,  and  the  lymphatics  of  the  mammary  gland. 

The  Deep  lymphatics  accompany  the  vessels  of  the  upper  extremity,  and 
communicate  occasionally  with  the  superficial  lymphatics.  They  enter  the 
axillary  and  subciavian  glands,  and,  at  the  root  of  the  neck  terminate  on 
the  left  side  in  the  thoracic  duct,  and  on  the  right  side  in  the  ductus  lym- 

phaticus  dexter. 

| 

LYMPHATICS  OF  THE  LOWER  EXTREMITY. 

The  Superficial  lymphatic  glands  of  the  lower  extremity  are  those  of  the 
groin,  the  inguinal;  and  one  or  two  situated  in  the  superficial  fascia  of  the 
posterior  aspect  of  the  thigh,  just  above  the  popliteal  region. 

The  Inguinal  glands  are  divisible  into  two  groups ;  a  superior  group  of  small 
size,  situated  along  the  course  of  Poupart's  ligament,  and  receiving  the 
lymphatic  vessels  from  the  parietes  of  the  abdomen,  gluteal  region,  peri- 
neum, and  genital  organs ;  and  an  inferior  group  of  larger  glands  clustered 
around  the  internal  saphenous  vein  near  its  termination,  and  receiving  the 
superficial  lymphatic  vessels  from  the  lower  extremity. 

The  Deep  lymphatic  glands  are  the  anterior  tibial,  popliteal,  deep  ingui- 
nal^ gluteal,  and  ischiatic. 

The  Anterior  tibial  is  generally  a  single  gland,  placed  on  the  interosse- 
ous  membrane,  by  the  side  of  the  anterior  tibial  artery  in  the  upper  part 
of  its  course. 

The  Popliteal  glands,  four  or  five  in  number  and  small,  are  embedded 
in  the  loose  areolar  tissue  and  fat  of  the  popliteal  space. 

The  Deep  inguinal  glands,  less  numerous  and  smaller  than  the  superficial, 
are  situated  near  the  femoral  vessels  in  the  groin,  beneath  the  fascia  lata. 

The  Gluteal  and  ischiatic  glands  are  placed  near  the  vessels  of  that 
name,  above  and  below  the  pyriformis  muscle  at  the  great  ischiatic 
foramen. 

The  Superficial  lymphatic  vessels  are  divisible  into  two  groups,  internal 
and  external ;  the  internal  and  principal  group,  commencing  on  the  dorsum 
and  inner  side  of  the  foot,  ascend  the  leg  by  the  side  of  the  internal  sa- 
phenous vein,  and  passing  behind  the  inner  condyle  of  the  femur,  follow 
the  direction  of  that  vein  to  the  groin,  where  they  join  the  saphenous  group 
of  superficial  inguinal  glands.  The  greater  part  of  the  efferent  vessels  from 


356  LYMPHATICS  OF  THE  TRUNK. 

these  glands  pierce  the  cribriform  fascia  of  the  saphenous  opening  and  the 
sheath  of  the  femoral  vessels,  to  join  the  lymphatic  gland  situated  in  tho. 
femoral  ring,  which  serves  to  establish  a  communication  between  the  lym- 
phatics of  the  lower  extremity  and  those  of  the  trunk.  The  other  efferent 
vessels  pierce  the  fascia  lata  to  join  the  deep  glands.  The  vessels  which 
pass  upwards  from  the  outer  side  of  the  dorsum  of  the  foot,  ascend  along 
the  outer  side  of  the  leg,  and  curve  inwards  just  below  the  knee,  to  unite 
with  the  lymphatics  of  the  inner  side  of  the  thigh.  The  external  group 
consists  of  a  few  lymphatic  vessels  which  commence  on  the  outer  side  of 
the  foot  and  posterior  part  of  the  ankle,  and  accompany  the  external 
saphenous  vein  to  the  popliteal  region,  where  they  enter  the  popliteal 
glands. 

The  Deep  lymphatic  vessels  accompany  the  deep  veins,  and  communi- 
cate with  the  various  glands  in  their  course.  After  joining  the  deep  in- 
guinal glands  they  pass  beneath  Poupart's  ligament,  to  communicate  with 
the  numerous  glands  situated  around  the  iliac  vessels.  The  deep  lym- 
phatics of  the  gluteal  region  follow  the  course  of  the  branches  of  the  gluteal 
and  ischiatic  arteries.  The  former  join  the  glands  situated  on  the  upper 
border  of  the  pyriformis  muscle,  and  the  latter,  after  communicating  with 
the  lymphatics  of  the  thigh,  enter  the  ischiatic  glands. 

LYMPHATICS    OF    THE     TRUNK. 

The  lymphatics  of  the  trunk  may  be  arranged  under  three  heads,  super- 
ficial, deep,  and  visceral. 

The  Superficial  lymphatic  vessels  of  the  upper  half  of  the  trunk  pass 
upwards  and  outwrards  on  each  side,  and  converge,  some  to  the  axillary 
glands,  and  others  to  the  glands  at  the  root  of  the  neck.  The  lymphatics 
from  the  mammary  glands  follow  the  lower  border  of  the  pectoralis  major, 
communicating,  by  means  of  a  chain  of  lymphatic  glands,  with  the  axil- 
lary glands.  The  superficial  lymphatic  vessels  of  the  lower  half  of  the 
trunk,  of  the  gluteal  region,  perineum,  and  external  organs  of  generation, 
converge  to  the  superior  group  of  superficial  inguinal  glands.  Some  small 
glands  are  situated  on  each  side  of  the  dorsal  vein  of  the  penis,  near  the 
suspensory  ligament ;  from  these,  as  from  the  superficial  lymphatics,  the 
efferent  vessels  pass  into  the  superior  group  of  superficial  inguinal  glands. 

The  Deep  lymphatic  glands  of  the  thorax  are  the  intercostal,  internal 
mammary,  anterior  mediastinal,  and  posterior  mediastinal. 

The  Intercostal  glands  are  of  small  size,  and  are  situated  on  each  side 
of  the  vertebral  column,  near  the  articulations  of  the  heads  of  the  ribs,  and 
in  the  course  of  the  intercostal  arteries. 

The  Internal  mammary  glands,  also  very  small,  are  placed  in  the  inter- 
costal spaces,  by  the  side  of  the  internal  mammary  arteries. 

The  Anterior  mediastinal  glands  occupy  the  loose  areolar  tissue  of  the 
anterior  mediastinum,  resting  some  on  the  diaphragm,  but  the  greater 
number  on  the  large  vessels  at  the  root  of  the  heart. 

The  Posterior  mediastinal  glands  are  situated  along  the  course  of  the 
aorta  and  oesophagus  in  the  posterior  mediastinum,  and  communicate 
above  with  the  deep  cervical  glands,  on  each  side  with  the  intercostal  and 
below  with  the  abdominal  glands. 

The  Deep  lymphatic  vessels  of  the  thorax  are  the  intercostal,  internal 
mammary,  and  diaphragmatic. 


LYMPHATICS    OF    THE    VISCERA.  357 

The  Intercostal  lymphatic  vessels  follow  the  course  of  the  arteries  of  the 
same  name ;  and  reaching  the  vertebral  column  curve  downwards  to  ter- 
minate in  the  thoracic  duct. 

The  Internal  mammary  lymphatics  commence  in  the  parieties  of  the 
abdomen,  communicating  with  the  epigastric  lymphatics.  They  ascend 
by  the  side  of  the  internal  mammary  vessels,  being  joined  in  their  course 
by  the  anterior  intercostals,  and  terminate  at  the  root  of  the  neck,  on  the 
right  side  in  the  tributaries  of  the  ductus  lymphaticus  dexter,  and  on  the 
left  in  the  thoracic  duct.  The  diaphragmatic  lymphatics  pursue  the  direc^ 
tion  of  their  corresponding  veins,  and  terminate  some  in  front  in  the  in- 
ternal mammary  vessels,  and  some  behind,  in  the  posterior  mediastinal 
lymphatics. 

The  Deep  lymphatic  glands  of  the  abdomen  are.  the  lumbar  glands ;  they 
are  very  numerous,  and  are  seated  around  the  common  iliac  vessels,  the 
aorta  and  vena  cava. 

The  deep  lymphatic  glands  of  the  pelvis  are  the  external  iliac,  internal, 
iliac  and  sacral. 

The  External  iliac  are  placed  around  the  external  iliac  vessels,  being 
in  continuation  by  one  extremity  with  the  femoral  lymphatics,  and  by  the 
other  with  the  lumbar  glands. 

The  Internal  iliac  glands  are  situated  in  the  course  of  the  internal  iliac 
vessels,  and  the  sacral  glands  are  supported  by  the  concave  surface  of  the 
sacrum. 

The  Deep  lymphatic  vessels  are  continued  upwards  from  the  thigh,  be- 
neath Poupart's  ligament,  and  along  the  external  iliac  vessels  to  the  lum- 
bar glands,  receiving  in  their  course  the  epigastric,  circumflexa  ilii,  and 
ilio-lumbar  lymphatic  vessels.  Those  from  the  parietes  of  the  pelvis,  and 
from  the  gluteal,  ischiatic,  and  obturator  vessels,  follow  the  course  of  the 
internal  iliac  arteries,  and  unite  with  the  lumbar  lymphatics.  And  the 
lumbar  lymphatic  vessels,  after  receiving  all  the  lymphatics  from  the  lower 
extremities,  pelvis,  and  loins,  terminate  by  several  large  trunks  in  the 
receptaculum  chyli. 

LYMPHATICS    OF    THE    VISCERA. 

The  Lymphatic  vessels  of  the  lungs  are  of  large  size,  and  are  distributed 
over  every  part  of  the  surface,  and  through  the  texture  of  these  organs ; 
they  converge  to  the  numerous  glands  situated  around  the  bifurcation  of 
the  trachea  and  roots  of  the  lungs,  the  bronchial  glands.  Some  of  these 
glands  of  small  size,  may  be  traced  in  connexion  with  the  bronchial  tubes 
for  some  distance  into  the  lungs.  The  efferent  vessels  from  the  bronchial 
glands  unite  with  the  tracheal  and  oesophageal  glands,  and  terminate  prin- 
cipally in  the  thoracic  duct  at  the  root  of  the  neck,  and  partly  in  the  duc- 
tus lymphaticus  dexter.  The  bronchial  glands,  in  the  adult,  present  a 
variable  tint  of  brown,  and  in  old  age  a  deep  black  colour.  In  infancy 
they  have  none  of  this  pigment,  and  are  not  to  be  distinguished  from  lym- 
phatic glands  in  other  situations. 

The  Lymphatic  vessels  of  the  heart  originate  in  the  subserous  areolar 
tissue  of  the  surface,  and  in  the  deeper  tissues  of  the  organ,  and  follow 
the  course  of  the  vessels,  principally,  along  the  right  border  of  the  heart 
to  the  glands  situated  around  the  arch  of  the  aorta  and  to  the  bronchia] 


358  LYMPHATICS    OF   THE   VISCERA. 

glands,  whence  they  proceed  to  the  root  of  the  neck,  and  terminate  in  the 
thoracic  duct. 

The  Pericardiac  and  thymic  lymphatic  vessels  proceed  to  join  the  ante- 
rior mediastinal  and  bronchial  glands. 

The  Lymphatic  vessels  of  the  liver  are  divisible  into  the  deep  and  su- 
perficial. The  former  take  their  course  through  the  portal  canals,  and 
through  the  right  border  of  the  lesser  omentum,  to  the  lymphatic  glands 
situated  in  the  course  of  the  hepatic  artery  and  along  the  lesser  curve  of 
the  stomach.  The  superficial  lymphatics  are  situated  in  the  areolar  struc 
ture  of  the  proper  capsule,  over  the  whole  surface  of  the  liver.  Those  of 
the  convex  surface  are  divided  into  two  sets ; — 1.  Those  which  pass  from 
before  backwards ;  2.  Those  which  advance  from  behind  forwards.  The 
former  unite  to  form  trunks,  which  enter  between  the  folds  of  the  lateral 
ligaments  at  the  right  and  left  extremities  of  the  organ,  and  of  the  coronary 
ligament  in  the  middle.  Some  of  these  pierce  the  diaphragm  and  join 
the  posterior  mediastinal  glands ;  others  converge  to  the  lymphatic  glands 
situated  around  the  inferior  cava.  Those  which  pass  from  behind  for- 
wards consist  of  two  groups :  one  ascends  between  the  folds  of  the  broad 
ligament,  and  perforates  the  diaphragm,  to  terminate  in  the  anterior  medi- 
astinal glands ;  the  other  curves  around  the  anterior  margin  of  the  liver 
to  its  concave  surface,  and  from  thence  to  the  glands  in  the  right  border 
of  the  lesser  omentum.  The  lymphatic  vessels  of  the  concave  surface 
are  variously  distributed,  according  to  their  position  ;  those  from  the  right 
lobe  terminate  in  the  lumbar  glands ;  those  from  the  gall-bladder,  which 
are  large  and  form  a  remarkable  plexus,  enter  the  glands  in  the  right  bor- 
der of  the  lesser  omentum  ;  and  those  from  the  left  lobe  converge  to  the 
lymphatic  glands  situated  along  the  lesser  curve  of  the  stomach. 

The  Lymphatic  glands  of  the  spleen  are  situated  around  its  hilus,  and 
those  of  the  pancreas  in  the  course  of  the  splenic  vein.  The  lymphatic 
vessels  of  these  organs  pass  through  their  respective  glands,  and  join  the 
aortic  glands,  previously  to  terminating  in  the  thoracic  duct. 

The  Lymphatic  glands  of  the  stomach  are  of  small  size,  and  are  situated 
along  the  lesser  and  greater  curves  of  that  organ.  The  lymphatic  vessels, 
as  in  other  viscera,  are  superficial  and  deep,  the  former  originating  in  the 
subserous  and  the  latter  in  the  submucous  tissue  ;  they  pass  from  the  sto- 
mach in  four  different  directions:  some  ascend  to  the  glands,  situated 
along  the  lesser  curve,  others  descend  to  those  occupying  the  greater 
curve,  a  third  set  pass  outwards  to  the  splenic  glands,  and  a  fourth  to  the 
glands  situated  near  the  pylorus  and  to  the  aortic  glands. 

The  Lymphatic  glands  of  the  small  intestine  are  situated  between  the 
layers  of  the  mesentery,  in  the  meshes  formed  by  the  superior  mesenteric 
artery,  and  are  thence  named  mesenteric  glands.  These  glands  are  most 
numerous  and  largest,  superiorly,  near  the  duodenum ;  and,  inferiorly, 
near  the  termination  of  the  ileum. 

The  Lymphatic  vessels  of  the  small  intestines  are  of  two  kinds :  those 
of  the  structure  of  the  intestines,  which  run  upon  its  surface  pre- 
viously to  entering  the  mesenteric  glands  ;  and  those  which  commence 
in  the  villi,  in  the  substance  of  the  mucous  membrane,  and  am  named 
lacteals. 

The  Lacteals,  according  to  Henle,  commence  in  the  centre  of  each  vil- 
?us  as  a  caecal  tubulus,  which  opens  into  a  fine  network,  situated  in  the 


THORACIC    DUCT.  359 

sub-mucous  tissue.  From  this  areolar  network  the  .acteal  vessels  proceed 
to  the  mesenteric  glands,  and  from  thence  to  the  thoracic  duct,  in  which 
they  terminate. 

The  Lymphatic  glands  of  the  large  intestines  are  situated  along  the  at- 
tached margin  of  the  intestine,  in  the  meshes  formed  by  the  colic  and 
hsemorrhoidal  arteries  previously  to  their  distribution.  The  lymphatic 
vessels  take  their  course  in  two  different  directions ;  those  of  the  caecum 
ascending  and  transverse  colon,  after  traversing  their  proper  glands,  pro- 
ceed to  the  mesenteric,  and  those  of  the  descending  colon  and  rectum  to 
the  lumbar  glands. 

The  Lymphatic  vessels  of  the  Jcidney  follow  the  direction  of  the  blood- 
vessels to  the  lumbar  glands  situated  around  the  aorta  and  inferior  vena 
cava ;  those  of  the  supra-renal  capsules,  which  are  very  large  and  nume- 
rous, terminate  in  the  real  lymphatics. 

The  Lymphatic  vessels  of  the  viscera  of  the  pelvis  terminate  in  the  sacral 
and  lumbar  glands. 

The  Lymphatic  vessels  of  the  testicle  take  the  course  of  the  spermatic 
cord  in  which  they  are  of  large  size ;  they  terminate  in  the  lumbar  glands. 


THORACIC    DUCT. 

The  thoracic  duct*  commences  in  the  abdomen,  by  a  considerable  and 
somewhat  triangular  dilatation,  the  receptaculum  chyli',  which  is  situated 
on  the  front  of  the  body  of  the  second  lumbar  vertebra,  behind  and  be- 
tween the  aorta  and  inferior  vena  cava,  and  close  to  the  tendon  of  the 
right  crus  of  the  diaphragm.  From  the  upper  part  of  the  receptaculum 
chyli  the  thoracic  duct  ascends  through  the  aortic  opening  of  the  dia- 
phragm, and  along  the  front  of  the  vertebral  column,  lying  between  the 
thoracic  aorta  and  vena  azygos,  to  the  fourth  dorsal  vertebra.  It  then  in- 
clines to  the  left  side,  passes  behind  the  arch  of  the  aorta,  and  ascends  by 
the  side  of  the  resophagus  and  behind  the  perpendicular  portion  of  the 
left  subclavian  artery  to  the  root  of  the  neck  opposite  the  seventh  cervical 
vertebra,  where  it  makes  a  sudden  curve  forwards  and  downwards,  and 
terminates  at  the  point  of  junction  of  the  left  subclavian  with  the  left  in- 
ternal jugular  vein. 

The  thoracic  duct  is  equal  in  size  to  the  diameter  of  a  goose-quill  at  its 
commencement  from  the  receptaculum  chyli,  diminishes  considerably  in 
diameter  towards  the  middle  of  the  posterior  mediastinum,  and  again  be- 
comes dilated  near  its  termination.  At  about  the  middle  of  the  thorax  it 
frequently  divides  into  two  branches  of  equal  size,  which  reunite  after  a 
short  course  ;  and  sometimes  it  gives  off  several  branches,  which  assume 
a  plexiform  arrangement  in  this  situation.  Occasionally  the  thoracic  duct 
bifurcates  at  the  upper  part  of  the  thorax  into  two  branches,  one  of  which 
opens  into  the  point  of  junction  between  the  right  subclavian  and  jugular 
veins,  while  the  other  proceeds  to  the  normal  termination  of  the  duct  on 
the  left  side.  In  rare  instances  the  duct  has  been  found  to  terminate  ir 
the  vena  azygos,  which  is  its  normal  destination  in  some  Mammalia. 

*  The  thoracic  duct  was  discovered  by  Eustachius,  in  1563,  in  the  horse  :  he  regarded 
it  as  a  vein,  and  called  it  the  vena  alba  thoracis.  The  lacteals  were  first  seen  by  Asel 
lius  in  1622,  in  the  dog;  and  within  the  next  ten  years  by  Veslingius  in  man. 


Fig.  167* 


360  THORACIC   DUCT. 

The  thoracic  duct  presents  fewer  valves  in 
its  course  than  lymphatic  vessels  generally  ;  at 
its  termination  it  is  provided  with  a  pair  of 
semilunar  valves,  which  prevent  the  admission 
of  venous  blood  into  its  cylinder. 

Branches. — The  thoracic  duct  receives  at 
its  commencement  four  or  five  large  lymphatic 
trunks,  which  unite  to  form  the  receptaculum 
chyli :  it  next  receives  the  trunks  of  the  lacteal 
vessels.  Within  the  thorax  it  is  joined  by  a 
large  lymphatic  trunk  from  the  liver,  and  in 
its  course  through  the  posterior  mediastinum, 
receives  the  lymphatic  vessels  both  from  the 
viscera  and  from  the  parietes  of  the  thorax. 
At  its  curve  forwards  in  the  neck  it  is  joined 
by  the  lymphatic  trunks  from  the  left  side  of 
the  head  and  neck,  left  upper  extremity,  and 
from  the  upper  part  of  the  thorax,  and  thoracic 
viscera. 

The  Ductus  lymphatlcus  dexter  is  a  short 
trunk  which  receives  the  lymphatic  vessels 
from  the  right  side  of  the  head  and  neck,  right 
upper  extremity,  right  side  of  the  thorax,  right 
lung,  and  one  or  two  branches  from  the  liver, 
and  terminates  at  the  junction  of  the  right 
subclavian  with  the  right  internal  jugular  vein, 
at  the  point  where  these  veins  unite  to  form 
the  right  vena  innorninata.  It  is  provided  at 
its  termination  with  a  pair  of  semilunar  valves, 
which  prevent  the  entrance  of  blood  from  the 
veins. 

*  The  course  and  termination  of  the  thoracic  duct.  1.  The  arch  of  the  aorta.  2.  The 
thoracic  aorta.  3.  The  abdominal  aorta ;  showing  its  principal  branches  divided  near 
their  origin.  4.  The  arteria  innominata,  dividing  into  the  right  carotid  and  right  sub- 
clavian arteries.  5.  The  left  carotid.  6.  The  left  subclavian.  7.  The  superior  cava, 
formed  by  the  union  of  8,  the  two  venae  innominatae;  and  these  by  the  junction  9,  of 
the  internal  jugular  and  subclavian  vein  at  each  side.  10.  The  greater  vena  azygos. 
11.  The  termination  of  the  lesser  in  the  greater  vena  azygos.  12.  The  receptaculum 
chyli;  several  lymphatic  trunks  are  seen  opening  into  it.  13.  The  thoracic  duct,  divid- 
ing opposite  the  middle  of  the  dorsal  vertebrae  into  two  branches  which  soon  reunite  ; 
the  course  of  the  duct  behind  the  arch  of  the  aorta  and  left  subclavian  artery  is  shown 
by  a  dotted  line.  14.  The  duct,  making  its  turn  at  the  root  of  the  neck  and  receiving 
several  lymphatic  trunks  previously  to  terminating  in  the  posterior  aspect  of  the  junc- 
tion of  the  internal  jugular  and  subclavian  vein.  15.  The  termination  of  the  trunk  of 
the  ductus  lymphaticus  dexter. 


f 


ON    THE   NERVOUS    SYSTEM. 

CHAPTER  IX. 

ON  THE  NERVOUS  SYSTEM. 

THE  nervous  system  consists  of  a  central  organ,  the  cerebro-spinal  centre 
or  axis,  and  of  numerous  rounded  and  flattened  white  cords,  the  nerves, 
which  are  connected  by  one  extremity  with  the  cerebro-spinal  centre,  and 
by  the  other  are  distributed  to  all  the  textures  of  the  body.  The  sympa- 
thetic system  is  an  exception  to  this  description ;  for  in  place  of  one  it  has 
many  small  centres  which  are  called  ganglia,  and  which  communicate  very 
freely  with  the  cerebro-spinal  axis  and  with  its  nerves. 

The  cerebro-spinal  axis  consists  of  two  portions,  the  brain,  an  organ  of 
large  size,  situated  within  the  skull,  and  the  spinal  cord,  a  lengthened 
portion  of  the  nervous  centre  continuous  with  the  brain  and  occupying  the 
canal  of  the  vertebral  column. 

The  most  superficial  examination  of  the  brain,  and  spinal  cord  shows 
them  to  be  composed  of  fibres,  or  rather  fasciculi,  which  in  some  situations 
are  ranged  in  a  longitudinal  direction,  and  in  others  are  interlaced  at  va- 
rious angles  by  cross  fibres.  The  fasciculi  are  connected  and  held  together 
by  a  delicate  areolar  web,  wnich  forms  the  bond  of  support  to  the  entire 
organ.  It  is  also  observed  that  the  cerebro-spinal  axis  presents  two  sub- 
stances differing  from  each  other  in  density  and  colour :  a  grey  or  cineri- 
tious  or  cortical  substance,  and  a  white  or  medullary  substance.  The 
grey  substance  forms  a  thin  lamella  over  the  entire  surface  of  the  convolu- 
tions of  the  cerebrum,  and  of  the  lamina?  of  the  cerebellum :  hence  it  has 
been  named  cortical ;  but  the  grey  substance  is  not  confined  to  the  surface 
of  the  brain,  as  this  term  would  imply;  it  is  likewise  situated  in  the  centre 
of  the  spinal  cord  its  entire  length,  and  may  be  thence  traced  through 
the  medulla  oblongata,  crura  cerebri,  thalami  optici,  and  corpora  striata ; 
it  enters  also  into  the  composition  of  the  locus  perforatus,  tuber  cinereum, 
commissura  mollis,  pineal  gland,  pituitary  gland,  and  corpora  rhomboidea. 

Two  kinds  of  grey  substance  are  described  by  Rolando  as  existing  in 
the  spinal  cord ;  the  one  (substantia  cinerea  spongiosa  vasculosa]  is  the  ordi- 
nary grey  matter  of  the  cord,  and  the  other  (substantia  cinerea  gelatinosa) 
forms  part  of  the  posterior  cornua.  The  former  resembles  in  structure  the 
grey  matter  of  the  brain,  while  the  latter  is  composed  of  small  bodies  re- 
sembling the  blood  corpuscules  of  the  frog. 

The  fibres  of  the  cerebro-spinal  axis  are  arranged  into  two  classes,  di- 
verging and  converging.  The  diverging  fibres  proceed  from  the  medulla 
oblongata,  and  diverge  to  every  part  of  the  surface  of  the  brain  ;  while  the 
converging  fibres  commence  at  the  surface  and  proceed  inwards  towards 
the  centre,  so  as  to  connect  the  diverging  fibres  of  opposite  sides.  In  cer- 
tain parts  of  their  course  the  diverging  fibres  are  separated  by  the  grey 
substance,  and  increase  in  number  so  as  to  form  a  body  of  considerable 
size,  which  is  called  a  ganglion.  The  position  and  mutual  relations  of 
these  fibres  and  ganglia  may  be  best  explained  by  reference  to  the  mode 
of  development  of  the  cerebro-spinal  axis  in  animals  and  in  man. 

The  centre  of  the  nervous  system,  in  the  lowest  animals  possessed  of  a 
31 


362  NERVOUS  SYSTEM — DEVELOPMENT. 

lengthened  axis,  presents  itself  in  the  form  of  a  double  cord.  A  step 
higher  in  the  animal  scale,  and  knots  or  ganglia  are  developed  on  one  ex- 
tremity of  this  cord ;  such  is  the  most  rudimentary  condition  of  the  brain 
in  the  lowest  forms  of  vertebrata.  In  the  lowest  fishes  the  anterior  ex- 
tremity of  the  double  cord  displays  a  succession  of  five  pairs  of  ganglia. 
The  higher  fishes  and  amphibia  appear  to  have  a  different  disposition  of 
these  primitive  ganglia.  The  first  two  have  become  fused  into  a  single 
ganglion,  and  then  follow  only  three  pairs  of  symmetrical  ganglia.  But 
if  the  larger  pair  be  unfolded,  after  being  hardened  in  alcohol,  it  will  then 
be  seen  that  the  whole  number  of  ganglia  exist,  but  that  four  have  become 
concealed  by  a  thin  covering  that  has  spread  across  them.  This  condition 
of  the  brain  carries  us  upwards  in  the  animal  scale  even  to  Mammalia , 
e.  g.,  in  the  dog  or  cat  we  find,  first,  a  single  ganglion,  the  cerebellum; 
then  three  pairs  following  each  other  in  succession ;  and  if  we  unfold  the 
middle  pair,  we  shall  be  at  once  convinced  that  it  is  composed  of  two 
pairs  of  primitive  ganglia  concealed  by  an  additional  development.  Again, 
it  will  be  observed,  that  the  primitive  ganglia  of  opposite  sides,  at  first 
separate  and  disjoined,  become  connected  by  means  of  transverse  fibres  of 
communication  (commissures;  commissura,  a  joining).  The  office  of  these 
commissures  is  the  association  in  function  of  the  two  symmetrical  portions. 
Hence  wre  arrive  at  the  general  and  important  conclusion,  that  the  brain, 
among  the  lower  animals,  consists  of  primitive  cords,  primitive  ganglia 
upon  those  cords,  and  commissures  which  connect  the  substance  of  adjoin- 
ing ganglia,  and  associate  their  functions. 

In  the  development  of  the  cerebro-spinal  axis  in  man,  the  earliest  indi- 
cation of  the  spinal  cord  is  presented  under  the  form  of  a  pair  of  minute 
longitudinal  filaments  placed  side  by  side.  Upon  these,  towards  the  an- 
terior extremity,  five  pairs  of  minute  swellings  are  observed,  not  disposed 
in  a  straight  line  as  in  fishes,  but  curved  upon  each  other  so  as  to  corres- 
pond with  the  direction  of  the  future  cranium.  The  posterior  pair  soon 
become  cemented  on  the  middle  line,  forming  a  single  ganglion ;  the  se- 
cond pair  also  unite  with  each  other ;  the  third  and  fourth  pairs,  at  first 
distinct,  are  speedily  veiled  by  a  lateral  development,  which  arches  back- 
wards and  conceals  them ;  the  anterior  pair,  at  first  very  small,  decrease 
in  side,  and  become  almost  lost  in  the  increased  development  of  the  pre- 
ceding pairs. 

We  see  here  a  chain  of  resemblances  corresponding  with  the  progressive 
development  observed  in  the  lower  animals ;  the  human  brain  is  passing 
through  the  phases  of  improving  development,  which  distinguish  the  lowest 
from  the  lower  creatures :  and  we  are  naturally  led  to  the  same  conclusion 
with  regard  to  the  architecture  of  the  human  brain  that  we  were  led  to 
establish  as  the  principle  of  development  in  the  inferior  creatures,  namely, 
that  it  is  composed  of  primitive  cords,  primitive  ganglia  upon  those  cords, 
commissures  to  connect  those  ganglia,  and  developments  from  those 
ganglia. 

In  the  adult,  the  primitive  longitudinal  cords  have  become  cemented 
together,  to  form  the  spinal  cord.  But,  at  the  upper  extremity,  they  se- 
parate from  each  other  under  the  name  of  crura  cerebri.  The  first  pair 
of  ganglia,  developed  from  the  primitive  cords,  have  grown  into  the  cere- 
bellum; the  second  pair  (the  optic  lobes  of  animals)  have  become  the 
'.orpora  quadrigemina  of  man.  The  third  pair,  the  optic  thalami,  and  the 
fourth,  the  corpora  striata,  are  the  basis  of  the  hemispheres,  which,  the 


GREY    NERVE    FIBRES. 


363 


Fig.  168.* 


merest  lamina  in  the  fish,  have  become  the  largest  portion  of  the  brain  in 
man.  And  the  Jiflh  pair  (olfactory  lobes),  so  large  in  the  lowest  forms, 
have  dwindled  into  the  olfactory  bulbs  of  man. 

The  microscopic  elements  of  the  nervous  system,  are,  white  nerve- 
fibres,  grey  nerve-fibres,  nerve-cells,  and  nerve-granules. 

1.  WHITE  NERVE  FIBRES  are  the  chief  con- 
stituent of  the  brain,  the  spinal  cord,  and  the 
cerebro-spinal  nerves,  and  they  also  enter  into 
the  composition  of  the  sympathetic  nerve. 
They  present  some  variety  of  size  in  different 
parts  of  the  nervous  system,  measuring  in  the 
brain  between  5JSV  and  j^^ao  of  an  inch  in 
diameter,  and  in  the  cerebro-spinal  nerves  be- 
tween vjo'oo  an(l  scoff  °f  an  mcn-  As  a  general 
rule,  the  white  nerve-fibres  are  largest  in  the 
nerves,  smaller  where  they  enter  the  cerebro- 
spinal  mass,  and  smallest  at  their  termination, 
centrally,  in  the  grey  substance  of  the  surface  of  the  brain,  and,  periphe- 
rally, in  the  tissues  of  the  body.  In  structure,  each  white  nerve-fibre  is 
composed  of  a  transparent  and  structureless  cylindrical  tubule  or  sheath 
(vagina  medullaris),  and  of  an  axis-cylinder  filled  with  an  opalescent, 
colourless,  oil-like  fluid  (neurine),  which  coagulates  after  death,  and  then 
resembles  a  white,  opaque,  and  curd-like  matter.  The  vagina  medullaris 
possesses  somewhat  less  than  one-third  the  thickness  of  the  entire  fibre 
and  gives  to  the  latter,  when  examined  with  the  microscope,  the  aspect 
of  a  double  cylinder,— an  appearance  which  is  characteristic  of  the  white 
nerve-fibre.  It  is  thickest  in  the  fibres  of  the  spinal  nerves,  and  thinnest 
in  those  of  the  spinal  cord,  brain,  and  nerves  of  special  sense.  Hence  in 
these  latter,  the  sheath,  when  pressed  or  stretched,  is  apt  to  assume  a 
varicose  appearance,  and  the  contained  substance  to  accumulate  in  small 
separate  masses.  White  nerve-fibres  terminate,  both  at  the  surface  of  the 
body,  in  the  various  internal  organs,  and  in  the  substance  of  the  cerebro- 
spinal  axis,  by  forming  loops. 

2.  GREY  NERVE  FIBRES  (fine  nerve-fibres,  gelatinous  fibres,  sympathetic 
fibres)  are  about  one-half  or  one-third  less  in  diameter  („»,„  to  sff'BW  of  an 
inch,  Henle)  than  the  white  fibres.  They  are  less  transparent,  have  no 
appearance  of  being  composed  of  a  double  cylinder,  and  their  sheath  is 
less  easily  distinguishable  from  its  contents.  In  structure,  they  consist  of 
a  thin  and  finely  granulated  sheath,  filled  with  granular  substance,  and, 
when  collected  into  a  fasciculus,  have  a  yellowish  grey  tint.  The  grey 
nerve-fibres  are  abundant  in,  and  are  indeed  the  chief  constituent  of,  the 
sympathetic  system.  They  are  also  present  in  the  cerebro-spinal  nerves, 
and,  most  numerously,  in  the  nerves  of  sensation.  They  take  their  origin 
frozn  the  nerve-cells  of  the  grey  substance  of  the  brain  and  spinal  cord, 

*  Minute  structure  of  nerve.  1.  The  mode  of  termination  of  white  nerve-fibres  in 
loops;  three  of  these  loops  are  simple,  the  fourth  is  convoluted.  The  latter  is  found  in 
situations  where  an  exalted  degree  of  sensation  exists.  2.  A  white  nerve-fibre  from 
the  brain,  showing  the  varicose  appearance  produced  by  traction  or  pressure.  3.  A 
white  nerve-fibre  enlarged  to  show  its  structure, — namely,  a  tubular  envelope,  and  a 
contained  substance,  neurine.  4.  A  nerve-cell,  showing  its  composition  of  a  granular 
looking  capsule  and  granular  contents.  5.  Its  nucleus  containing  a  nucleolus.  6.  A 
nerve-cell  from  which  several  processes  are  given  off.  It  contains,  like  he  preceding, 
a  nucleolated  nucleus.  7.  Nerve-granules. 


364  NERVE  CELLS — NERVE  GRANULES. 

from  those  of  Lie  ganglia  on  the  posterior  roots  of  the  cerebro-spinal 
nerves,  and  from  the  nerve-cells  of  the  ganglia  of  the  sympathetic  system. 

3.  The  NERVE-CELLS  are  spherical  or  oval,  or  polyhedral  in  shape,  of  a 
reddish  grey  colour,  and  between  ^fa  and  j^  of  an  inch  in  diameter. 
Each  cell  is  composed  of  a  capsular  sheath,  and  contains  in  its  interior  a 
reddish-grey  granular  substance,  and  one  or  more  nuclei  and  nucleoli, 
the  nucleus  being  attached  to  the  internal  surface  of  the  sheath.     The 
sheath  of  the  nerve-cell  is  constructed  of  three  layers,  the  outermost  con- 
sisting of  fine  granular  corpuscles,  the  middle  of  nucleated  cells  of  an 
oblong  figure,  and  the  internal  of  concentric  lamella?  of  delicate  cylindrical 
filaments.  Dispersed  through  the  substance  of  the  cell  are  a  greater  or  less 
number  of  pigment-granules,  some  being  in  the  interior,  and  some  in  the 
sheath.  Nerve-cells  are  found  in  the  grey  substance  of  the  brain  and  spinal 
cord,  in  the  ganglia  of  the  cerebro-spinal  nerves,  and  in  the  sympathetic 
ganglia  and  nerves.     The  nerve-cells  of  the  grey  substance  of  the  brain 
are  often  very  irregular  in  shape,  and  they  are  also  remarkable  for  their 

oftness  and  for  the  thinness  of  their  sheath.  It  is  the  pigment-granules, 
contained  in  the  nerve-cells  and  nerve-granules,  that  give  the  peculiar  tint 
of  colour  to  the  grey  and  dark  substance  of  the  cerebro-spinal  axis. 

In  the  grey  substance  of  the  brain  the  nerve-cells  may  be  seen  in 
various  stages  of  progressive  development ;  thus,  near  the  periphery,  they 
are  minute,  spherical  or  oval,  nucleated  cells  dispersed  through  a  matrix 
of  granular  substance ;  more  deeply,  the  granular  substance  is  collected 
around  the  cells,  and  forms  an  exterior  coat ;  while,  at  a  greater  depth, 
the  cells  have  attained  the  size  and  the  laminated  sheaths  of  the  fully 
formed  nerve-cells.  Nerve-cells  offer  many  peculiarities  in  respect  of 
number  and  arrangement  in  different  parts  of  the  nervous  system. 

From  the  periphery  of  the  nerve-cells  one  or  more  delicate  thread-like 
processes,  between  ^v  anc^  TITOUS  °f  an  mc^  ^n  diameter,  are  given  off 
These  are  the  origins  of  the  grey  nerve-fibres. 

4.  NERVE  GRANULES  present  the  three  forms  of,  minute  homogeneous 
particles,  aggregated  particles,  and  nucleated  corpuscles,  varying  in  size 
between  g^ou  and  T^OU  °f  an  inch  in  diameter.     They  serve  as  the  bond 
of  connexion  between  the  fibres  and  cells  of  the  brain  and  spinal  cord, 
particularly  in  the  grey  substance ;  and  enter  also  into  the  composition  of 
the  various  ganglia.     Like  nerve-cells,  nerve-granules  contain,  and  have 
intermingled  with  them,  a  variable  number  of  pigment-granules. 

In  the  construction  of  a  nerve  the  nerve-fibres  are  collected  into  small 
fasciculi,  each  fasciculus  being  invested  by  a  distinct  neurilemma.  These 
fasciculi,  again,  are  collected  into  bundles,  forming  larger  fasciculi,  which 
have  also  a  separate  neurilemma ;  and  a  bundle  of  the  larger  fasciculi, 
enclosed  in  a  sheath  or  neurilemma  of  white  fibrous  tissue,  constitutes  a 
nerve  The  neurilemma  of  the  smaller  fasciculi  is  smooth  and  semitrans- 
parent,  and  remarkable  for  its  satiny  polish, — an  appearance  which  is  due 
to  the  longitudinal  arrangement  of  the  undulating  fasciculi  of  fibrous  tissue 
of  which  it  is  composed.  Another  character  which  the  smaller  nervous 
fasciculi  possess,  is  that  of  being  crossed  by  oblique  or  transverse  lines, 
which  are  produced,  in  all  probability,  by  the  wrinkling  of  the  neurilemma. 

In  the  fasciculi  of  grey  fibres  the  tendency  to  wrinkle  exists  in  the  lon- 
gitudinal direction,  and  the  neurilemma  is  composed  of  an  inner  layer  of 
circular  filaments  as  well  as  an  outer  layer  of  the  longitudinal  filaments  of 
fibrous  tissue 


CONSTRUCTION    OF    NERVES.  365 

The  nerve-fibres  have  no  inosculations,  but  pursue  an  uninterrupted 
course  from  their  central  to  their  peripheral  termination.  In  some  instances 
they  return  after  a  short  curve  to  the  cerebro-spinal  centre,  as,  for  example, 
in  the  posterior  part  of  the  optic  commissure,  in  the  two  roots  of  each 
spinal  nerve,  and  in  the  loop  formed  between  the  descendens  noni  and 
the  -ipper  cervical  nerves.  In  these  cases,  the  fibres  form  a  simple  arch, 
both  extremities  of  the  arch  maintaining  a  communication  with  the  cerebro- 
spinal  axis.  In  another  instance,  the  direction  of  the  curve  is  reversed, 
the  centre  of  the  arch  being  in  the  anterior  part  of  the  optic  commissure, 
and  the  extremities  in  the  retina. 

The  communications  which  take  place  between  nerves  are  termed 
plexuses.  These  plexuses  are  sometimes  formed  by  the  trunks  of  the 
nerves,  as,  the  cervical,  brachial,  and  lumbar ;  and  sometimes  by  the  fas- 
ciculi, as  in  the  terminal  plexuses  at  the  periphery  of  the  body  and  at  the 
surface  of  the  brain.  The  nerve-fibres  in  the  spinal  cord  and  central  parts 
of  the  brain  also  form  a  close  and  plexiform  interlacement  with  each  other. 
In  the  construction  of  the  larger  plexuses  there  is  a  free  interchange  of 
fasciculi,  and  in  the  terminal  plexuses  a  similar  interchange  of  smaller  fas- 
ciculi and  primitive  fibres.  It  is  from  the  terminal  plexuses  that  the  nerve- 
fibres  pass  off  to  form  their  terminal  loops. 

The  general  mode  of  termination  of  nerve-fibres  is  by  loops.  There 
exists,  however,  an  exception  to  this  rule  in  the  instance  of  the  Pacinian* 
corpuscles.  These  corpuscles  are  minute  bodies,  about  a  line  in  length, 
of  an  oval,  oblong,  or  spheroidal  shape,  and  smooth  and  glistening  aspect, 
connected  with  the  terminal  nerve-fibres  of  the  digital  branches  of  the 
nerves  distributed  to  the  hands  and  feet.  As  many  as  two  or  three  hun- 
dred are  met  with  in  a  single  hand.  They  are  also  found,  but  less  nume- 
rously, on  the  terminal  fibres  of  other  sensitive  nerves,  and  on  the  fibres 
of  the  sympathetic  plexuses  of  the  mesentery,  of  the  meso-colon,  and  of 
the  pancreas.  They  occur  singly  and  in  groups  of  two  or  three,  and  are 
each  connected  with  the  nerve  by  means  of  a  short  pedicle  which  projects 
into  the  corpuscle,  and  forms  a  conical  process  in  its  interior.  The  Paci- 
nian corpuscle  and  its  pedicle  are  composed  of  about  fifty  thin  and  mem- 
branous tunics,  which  are  closely  adherent  in  the  latter,  but  are  separated 
in  the  corpuscle  by  an  albuminous  fluid,  and  towards  the  free  end  of  the 
corpuscle,  the  tunics  are  connected  by  imperfect  septa.  The  central 
tunic  or  capsule  is  also  filled  with  fluid,  and  into  this  fluid  the  axis  cylin- 
der of  a  primitive  nervous  fibril,  derived  from  the  nerve  and  continued 
through  the  centre  of  the  peduncle,  is  prolonged.  According  to  Henle 
and  Kb'lliker,  this  nervous  fibril  generally  terminates  in  a  small  rounded 
enlargement ;  at  other  times  it  bifurcates  and  forms  two  rounded  heads, 
and  occasionally  escapes  from  the  corpuscle  at  its  free  end.  Each  of  the 
tunics  of  the  Pacinian  body  is  composed  of  fibres  which  have  a  circular 
disposition  on  its  external  surface,  and  are  arranged  in  a  longitudinal 
direction  within.  It  is  these  fibres  which  give  to  the  corpuscle  its  glisten- 
ing appearance.  The  Pacinian  corpuscles  are  first  perceptible  during  the 
sixth  month  of  foetal  life. 

On  certain  of  the  nerves  of  the  body,  for  example,  on  the  posterior  roots 
of  the  cranial  and  spinal  nerves,  and  particularly  on  the  sympathetic,  are 
situated  enlargements  which  are  termed  ganglia.  Ganglia  are  greyish  in 

*  Discovered  and  described  by  Pacini  in  1831 ;  described  more  particularly  in  1840. 
»nd  by  Henle  and  Kolliker  in  1844. 

31* 


366  CLASSIFICATION    OF   NERVES. 

colour,  are  invested  by  a  smooth  membranous  sheath,  and  are  composed 
of  the  three  essential  constituents  of  the  nervous  system,  namely,  nerve- 
cells,  nerve-fibres,  and  nerve-granules.  The  nerve-cells  of  ganglia  are 
firm  in  structure,  and  have  stronger  investing  sheaths  than  those  of  the 
brain.  From  the  exterior  of  their  sheaths,  filaments  of  fibrous  tissue  are 
given  off,  which  interlace  with  each  other,  and  hold  the  cells  together ; 
and  at  the  same  time  form  an  investing  network  around  the  entire  gan- 
glion, the  nerve-fibres  passing  into  and  out  of  the  ganglion  through  the 
interstices  of  this  network.  Besides  the  sheath-filaments,  certain  of  the 
nerve-cells  give  off  grey  fibres,  while  others  are  free.  The  nerve-fibres  of 
ganglia  are  of  the  two  kinds  met  with  in  the  rest  of  the  nervous  system. 
The  white-fibres  are  derived  from  the  cerebro-spinal  axis,  and  enter  the 
sympathetic  through  the  so-called  roots  of  that  nerve,  namely,  its  commu- 
nications with  the  spinal  nerves.  In  the  ganglia  these  white  fibres  sepa- 
rate, and  either  pass  directly  onwards  between  the  nerve-cells  (traversing 
fibres),  or  make  a  series  of  turns  around  them  (winding  fibres) ;  in  either 
case,  they  collect  together  after  a  plexiform  course  between  the  nerve-cells, 
and  form  fasciculi,  which  pass  off  as  branches  from  the  ganglion.  The 
grey  nerve-fibres  originate  from  certain  of  the  nerve-cells  within  the  gan- 
glion as  finely  granular  threads,  and  pass  away  in  the  form  of  fasciculi, 
with  or  without  association  of  the  white  fibres,  to  be  distributed  to  the 
various  organs,  or  to  traverse  other  ganglia  previously  to  their  distribution. 
The  Nerve-granules  occupy  the  interstices  between  the  nerve-cells  and 
the  nerve-fibres,  as  in  the  cerebro-spinal  mass.  They  are  also  continued 
with  the  nerve-fibres,  into  some  of  the  nerves  given  off  by  the  ganglia. 
Like  the  interstitial  substance  of  the  brain,  the  granular  substance  (gela- 
tinous substance)  of  ganglia  has  intermingled  with  it  minute  cells  and 
pigment-granules. 

Nerves  are  divisible  into  two  great  classes ;  those  which  proceed  di- 
rectly from  the  cerebro-spinal  axis,  the  cranial  and  spinal  nerves,  and 
constitute  the  system  of  animal  life ;  and  those  which  originate  from  the 
sympathetic  system,  or  system  of  organic  life. 

The  division  of  nerves  into  cranial  and  spinal  is  purely  arbitrary,  and 
depends  on  the  circumstance  of  the  former  passing  through  the  foramina 
of  the  cranium,  and  the  latter  through  those  of  the  vertebral  column. 
With  respect  to  origin,  all  the  cranial  nerves,  with  the  exception  of  the 
first,  [olfactory,]  proceed  from  the  spinal  cord,  or  from  its  immediate  pro- 
longation into  the  brain.  The  spinal  nerves  arise  by  two  roots ;  anterior, 
which  proceeds  from  the  anterior  segment  of  the  spinal  cord,  and  possesses 
a  motor  function ;  and  posterior,  which  is  connected  with  the  posterior 
segment,  and  bestows  the  faculty  of  sensation.  The  motor  nerves  of 
the  cranium  are  shown  by  dissection  to  be  continuous  with  the  motor 
portion  of  the  cord,  and  form  one  system  with  the  motor  roots  of  the 
spinal  cord ;  while  the  nerves  of  sensation,  always  excepting  the  ol- 
factory, are  in  like  manner  traced  to  the  posterior  segment  of  the  cord, 
and  form  part  of  the  system  of  sensation.  To  these  two  systems  a  third 
was  added  by  Sir  Charles  Bell,  the  respiratory  system,  which  consists  of 
nerves  associated  in  the  function  of  respiration,  and  arising  from  the  side 
of  the  upper  part  of  the  spinal  cord  in  one  continuous  line,  which  he 
Ihence  named  the  respiratory  tract.  The  microscope  has  failed  in  making 
out  any  structural  distinction  between  the  anterior  and  posterior  roots  of 
the  spinal  nerves ;  but  the  latter  are  remarkable  for  the  Dossession  of  a 


ORIGIN    OF   NERVES — BRAIN.  367 

ganglion  near  their  attachment  with  the  cord.  This  ganglion  is  observed 
iipon  the  posterior  roots  of  all  the  spinal  nerves,  and  also  upon  the  corre- 
sponding root  of  the  fifth  cranial  nerve,  which  is  thence  considered  a  spinal 
cranial  nerve.  Upon  others  of  the  cranial  nerves  a  ganglion  is  found, 
which  associates  them  in  function  with  the  nerves  of  sensation,  and  estab- 
lishes an  analogy  with  the  spinal  nerves. 

According  to  Mr.  Grainger,  both  roots  of  the  spinal  nerves,  as  well  as 
of  most  of  the  cerebral,  divide  into  two  sets  of  fibres  upon  entering  the 
cord,  one  set  being  connected  with  the  gray  substance,  while  the  other  is 
continuous  with  the  white  or  fibrous  part  of  the  cord.  The  former  he 
considers  to  be  the  agents  of  the  excito-motory  system  of  Dr.  Marshall 
Hall ;  and  the  latter,  the  communication  with  the  brain  and  the  medium 
for  the  transmission  of  sensation  and  volition.  He  has  not  been  able  to 
trace  the  fibres  which  enter  the  gray  substance  to  their  termination ;  but 
he  thinks  it  probable  that  the  ultimate  fibres  of  the  posterior  root  join  those 
of  the  anterior  root ;  or,  in  the  words  of  Dr.  Marshall  Hall's  system,  that 
the  incident  fibres  (sensitive)  are  continuous  with  the  reflex  (motor). 

The  connexion  of  a  nerve  with  the  cerebro-spinal  axis  is  called,  for 
convenience  of  description,  its  origin :  this  term  must  not,  however,^be 
taken  literally,  for  each  nerve  is  developed  in  the  precise  situation  which 
it  occupies  in  the  body,  and  with  the  same  relations  that  it  possesses  in 
after  life.  Indeed,  we  not  unfrequently  meet  with  instances,  in  anenceph- 
alous  foetuses,  where  the  nerves  are  beautifully  and  completely  foimed, 
while  the  brain  and  spinal  cord  are  wanting.  The  word  "  origin"  must 
therefore  be  considered  as  a  relict  of  the  darkness  of  preceding  ages,  when 
the  cerebro-spinal  axis  was  looked  upon  as  the  tree  from  which  the  nerves 
pushed  forth  as  branches.  In  their  distribution,  the  spinal  nerves  for  the 
most  part  follow  the  course  of  the  arteries,  particularly  in  the  limbs,  where 
they  lie  almost  constantly  to  the  outer  side  and  superficially  to  the  vessels, 
as  if  for  the  purpose  of  receiving  the  first  intimation  of  danger  and  of  com- 
municating it  to  the  muscles,  that  the  latter  may  instantly  remove  the  arte- 
ries from  impending  injury. 

The  Sympathetic  system  consists  of  numerous  ganglia,  of  communicat- 
ing branches  passing  between  the  ganglia,  of  others  passing  between  the 
ganglia  and  the  cerebro-spinal  axis,  and  of  branches  of  distribution  which 
are  remarkable  for  their  frequent  and  plexiform  communications.  The 
sympathetic  nerves  also  differ  from  other  nerves  in  their  colour,  which  is 
of  a  grayish  pearly  tint. 

The  capillary  vessels  of  nerves  are  very  minute.  They  run  parallel 
with  the  nervous  fasciculi,  and  every  here  and  there  are  connected  by 
transverse  communications,  so  as  to  give  rise  to  a  net-work  composed  of 
oblong  meshes  very  similar  to  the  capillary  system  of  muscles. 

The  nervous  system  may  be  divided  for  convenience  of  description 
into  1.  The  brain.  2.  The  spinal  cord.  3.  The  cranial  nerves.  4.  The 
spinal  nerves.  5.  The  sympathetic  system. 


THE    BRAIN. 


The  brain  is  a  collective  term  which  signifies  those  parts  of  the  ne.-vous 
system,  exclusive  of  the  nerves  themselves,  which  are  contained  within  the 
cranium ;  they  are  the  cerebrum,  cerebellum,  and  medulla  oblongata.* 

*  The  weight  of  the  human  brain,  according  to  ScGmmering,  is  2ft.  5^5; .  t°  3ft.  1^.  7£. 


868  MEMBRANES  OF  THE  ENCEPHALON. 

These  are  invested  and  protected  by  the  membranes  of  the  brain,  and  the 
whole  together  constitute  the  encephalon  (£v  x?<paX>5,  within  the  head). 

MEMBRANES  OF  THE  ENCEPHALON. 

Dissection. — To  examine  the  encephalon  with  its  membranes,  the  upper 
part  of  the  skull  must  be  removed,  by  sawing  through  the  external  table 
and  breaking  the  internal  table  with  the  chisel  and  hammer.  After  the 
calvarium  has  been  loosened  all  round,  it  will  require  a  considerable  de- 
gree of  force  to  tear  the  bone  away  from  the  dura  mater.  This  adhesion 
is  particularly  firm  at  the  sutures,  where  the  dura  mater  is  continuous  with 
a  membranous  layer  interposed  between  the  edges  of  the  bones ;  in  other 
situations,  the  connexion  results  from  numerous  vessels  which  permeate 
the  inner  table  of  the  skull.  The  adhesion  subsisting  between  the  dura 
mater  and  bone  is  greater  in  the  young  subject  and  in  old  persons  than  in 
the  adult.  On  being  torn  awray,  the  internal  table  will  present  numerous 
deeply  grooved  and  ramified  channels,  corresponding  with  the  branches 
of  the  arteria  meningea  media.  Along  the  middle  line  will  be  seen  a  groove 
corresponding  with  the  superior  longitudinal  sinus,  and  on  either  side  may 
be  frequently  observed  some  small  fossae,  corresponding  with  the  Pacchi- 
onian  bodies. 

The  membranes  of  the  encephalon  are  the  dura  mater,  arachnoid  mem- 
brane, and  pia  mater. 

The  DURA  MATER*  is  the  firm,  whitish  or  greyish  layer  which  is  brought 
into  view  when  the  calvarium  is  removed.  It  is  a  strong  fibrous  membrane, 
somewhat  laminated  in  texture,  and  composed  of  white  fibrous  tissue. 
Lining  the  interior  of  the  cranium,  it  serves  as  the  internal  periosteum  of 
that  cavity ;  it  is  prolonged  also  into  the  spinal  column,  under  the  name 
of  theca  vertebralis,  but  is  not  adherent  to  the  bones  in  that  canal  as  in  the 
cranium.  From  the  internal  surface  of  the  dura  mater,  processes  are  di- 
rected inwards  for  the  support  and  protection  of  parts  of  the  brain ;  while 
from  its  exterior,  other  processes  are  prolonged  outwards  to  form  sheaths 
for  the  nerves  as  they  quit  the  skull  and  spinal  column.  Its  external  sur- 
face is  rough  and  fibrous,  and  corresponds  with  the  internal  table  of  the 
skull.  The  internal  surface  is  smooth,  and  lined  by  the  thin  varnish-like 
lamella  of  the  arachnoid  membrane.  The  latter  is  a  serous  membrane. 
Hence  the  dura  mater  becomes  a  fibro-serous  membrane,  being  composed 
of  its  own  proper  fibrous  structure,  and  the  serous  layer  derived  from  the 
arachnoid.  There  are  two  other  instances  of  fibro-serous  membrane  in  the 
body,  formed  in  the  same  way,  namely,  the  pericardium  and  tunica  albu- 
ginea  of  the  testicle. 

On  the  external  surface  of  the  dura  mater  the  branches  of  the  middle 
meningeal  artery  may  be  seen  ramifying;  and  in  the  middle  line  is  a  de- 
pressed groove,  formed  by  the  subsidence  of  the  upper  wall  of  the  superior 
longitudinal  sinus.  If  the  sinus  be  opened  along  its  course,  it  will  be 
found  to  be  a  triangular  channel,  crossed  at  its  lower  angle  by  numerous 
white  bands,  called  chordae  Willisii  ;f  granular  bodies  are  also  occasion- 
ally seen  in  its  interior,  these  are  glandulae  Pacchioni. 

*  So  named  from  a  supposition  that  it  was  the  source  of  all  the  fibrous  membranes  of 
the  body. 

t  Willis  lived  in  the  seventeenth  century;  he  was  a  great  defender  of  the  opinions 
of  Harvey. 


DURA    MATER.  369 

The  Glandula  Pacchioni*  are  small,  round,  whitish  granulations,  oc- 
curring singly  or  in  clusters,  and  forming  small  groups  of  various  size  along 
the  margin  of  the  longitudinal  fissure  of  the  cerebrum,  and  more  particu- 
larly near  the  summit  of  the  latter.  These  bodies  would  seem  to  be  of 
morbid  origin ;  they  are  absent  in  infancy,  increase  in  numbers  in  adult 
life,  and  are  abundant  in  the  aged.  They  are  generally  associated  with 
opacity  of  the  arachnoid  around  their  bases,  but  in  some  instances  are 
wanting  even  in  the  adult.  They  have  their  point  of  attachment  in  the  pia 
mater,  from  which  they  seem  to  spring,  carrying  with  them  the  arachnoid 
membrane,  and  then,  in  proportion  to  their  size,  producing  various  effects 
upon  contiguous  parts.  For  example,  when  small,  they  remain  free  or 
constitute  a  bond  of  adhesion  between  the  visceral  and  parietal  layer  of  the 
arachnoid ;  \vhen  of  larger  size  they  produce  absorption  of  the  dura  mater, 
and  as  the  degree  of  absorption  is  greater  or  less,  they  protrude  through 
that  membrane,  and  form  depressions  on  the  inner  surface  of  the  cranium, 
or  simply  render  the  dura  mater  thin  and  cribriform.  Sometimes  they 
cause  absorption  of  the  wall  of  the  longitudinal  sinus,  and  projecting  into 
its  cavity,  give  rise  to  the  granulations  described  in  connexion  with  that 
channel. 

If  the  student  cut  through  one  side  of  the  dura  mater,  in  the  direction 
of  his  incision  through  the  skull,  and  turn  it  upwards  towards  the  middle 
line,  he  will  observe  the  smooth  internal  surface  of  this  membrane.  He 
will  perceive  also  the  large  veins  of  the  hemispheres  filled  with  dark  blood, 
and  passing  from  behind  forwards  to  open  into  the  superior  longitudinal 
sinus ;  and  the  firm  connexion,  by  means  of  these  veins  and  the  Pacchi- 
onian  bodies,  between  the  opposed  surfaces  of  the  arachnoid  membrane. 
If  he  separate  these  adhesions  with  his  scalpel,  he  will  see  a  vertical  layer 
of  dura  mater  descending  between  the  hemispheres ;  and  if  he  draw  one 
side  of  the  brain  a  little  outwards,  he  will  be  enabled  to  perceive  the  ex- 
tent of  the  process  of  membrane,  which  is  called  the  falx  cerebri. 

The  processes  of  dura  mater  which  are  sent  inwards  towards  the  interior 
of  the  skull,  are  the  falx  cerebri,  tentorium  cerebelli,  and  falx  cerebelli. 

The  Falx  cerebri  (falx,  a  sickle),  so  named  from  its  sickle-like  appear- 
ance, narrow  in  front,  broad  behind,  and  forming  a  sharp  curved  edge 
below,  is  attached  in  front  to  the  crista  galli  process  of  the  ethmoid  bone, 
and  behind  to  the  tentorium  cerebelli. 

The  Tentorium  cerebelli  (tentorium,  a  tent)  is  a  roof  of  dura  mater, 
thrown  across  the  cerebellum  and  attached  at  each  side  to  the  margin  of 
the  petrous  portion  of  the  temporal  bone ;  behind,  to  the  transverse  ridge 
of  the  occipital  bone,  which  lodges  the  lateral  sinuses  ;  and  to  the  clinoid 
processes  in  front.  It  supports  the  posterior  lobes  of  the  cerebrum  and 
prevents  their  pressuref  on  the  cerebellum,  leaving  only  a  small  opening 
anteriorly,  for  the  transmission  of  the  crura  cerebri. 

The  Falx  cerebelli  is  a  small  process,  generally  double,  attached  to  the 
vertical  ridge  of  the  occipital  bone  beneath  the  lateral  sinus,  and  to  the 
tentorium.  It  is  received  into  the  indentation  between  the  two  hemi- 
spheres of  the  cerebellum. 

The  layers  of  the  dura  mater  separate  in  several  situations,  so  as  to  form 

*  These  bodies  are  incorrectly  described  as  conglobate  glands  by  Pacchioni,  in  an 
epistolatory  dissertation,  "  De  Glandulis  conglobatis  Dime  Meningis  indeque  ortis  Lynv 
phaticis  ad  Piam  Matrem  productis,"  published  at  Rome,  in  1705. 

•J-  In  leaping  animals,  as  tl  e  feline  and  canine  genera,  the  tentorium  forms  a  bony  tent 

T 


370  ARACHNOID  MEMBRANE. 

irregular  channels  which  receive  the  venous  blood.  These  are  the  sinuse* 
of  the  dura  mater,  which  have  been  described  at  page  338. 

The  student  cannot  see  the  tentorium  and  falx  cerebelli  until  the  brain 
is  removed ;  but  he  should  consider  the  attachments  of  the  former  on  the 
dried  skull,  for  he  will  have  to  incise  it  in  the  removal  of  the  brain.  He 
should  now  proceed  to  that  operation,  for  which  purpose  the  dura  mater 
is  to  be  incised  all  round,  on  a  level  with  the  section  through  the  skull, 
and  the  scissors  are  to  be  carried  deeply  between  the  hemispheres  of  the 
brain  in  front,  to  cut  through  the  anterior  part  of  the  falx ;  then  draw  the 
dura  mater  backwards,  and  leave  it  hanging  by  its  attachment  to  the  ten- 
torium. Raise  the  anterior  lobes  of  the  brain  carefully  with  the  hand,  and 
lift  the  olfactory  bulbs  from  the  cribriform  fossse  with  the  handle  of  the 
scalpel.  Then  cut  across  the  two  optic  nerves  and  internal  carotid  arte- 
ries. Next  divide  the  infundibulum  and  third  nerves,  and  carry  the  knife 
along  the  margin  of  the  petrous  bone  at  each  side,  so  as  to  divide  the  ten- 
torium near  its  attachment.  Cut  across  the  fourth,  fifth,  sixth,  seventh, 
and  eighth  nerves  in  succession  with  a  sharp  knife,  and  pass  the  scalpel  as 
far  down  as  possible  into  the  vertebral  canal,  to  sever  the  spinal  cord,  cut- 
ting first  to  one  side  and  then  to  the  other,  in  order  to  divide  the  vertebral 
arteries  and  first  cervical  nerves.  Then  let  him  press  the  cerebellum 
gently  upwards  with  the  fingers  of  the  right  hand,  the  hemispheres  being 
supported  with  the  left,  and  the  brain  will  roll  into  his  hand. 

The  Arteries  of  the  dura  mater  are  the  anterior  meningeal  from  the 
ethmoidal,  ophthalmic,  and  internal  carotid.  The  middle  meningeal  and 
meningea  parva  from  the  internal  maxillary.  The  inferior  meningeal  from 
the  ascending  pharyngeal  and  occipital  arteries ;  and  the  posterior  menin- 
geal from  the  vertebral. 

Its  Nerves  are  derived  from  the  nervi  molles  and  vertebral  plexus  of 
the  sympathetic,  from  the  Casserian  ganglion,  the  ophthalmic  nerve,  and 
sometimes  from  the  fourth.  The  branches  from  the  twro  latter  are  given 
off  while  those  nerves  are  situated  by  the  side  of  the  sella  turcica ;  they 
are  recurrent,  and  pass  backwards  between  the  layers  of  the  tentorium,  to 
the  lining  membrane  of  the  lateral  sinus.  Purkinje  describes  a  sympa- 
thetic plexus  of  considerable  size,  as  being  situated  around  the  vena 
Galeni  at  its  entrance  into  the  fourth  sinus.  The  filaments  from  this 
plexus  are  distributed  to  the  tentorium. 

Arachnoid  Membrane. 

The  Arachnoid  (a^a.-/yt\  sJVc,  like  a  spider's  web),  so  named  from  its 
extreme  tenuity,  is  the  serous  membrane  of  the  cerebro-spinal  centre ; 
and,  like  other  serous  membranes,  a  shut  sac.  It  envelopes  the  brain  and 
spinal  cord  (visceral  layer)  and  is  reflected  upon  the  inner  surface  of  the 
dura  mater  (parietal  layer),  giving  to  that  membrane  its  serous  investment. 

On  the  upper  surface  of  the  hemispheres  the  arachnoid  is  transparent, 
but  may  be  demonstrated  as  it  passes  across  the  sulci  from  one  convolu- 
tion to  another  by  injecting,  with  a  blow-pipe,  a  stream  of  air  beneath  it. 
At  the  base  of  the  brain  the  membrane  is  opalescent  and  thicker  than  in 
other  situations,  and  more  easily  demonstrable  from  the  circumstance  of 
stretching  across  the  interval  between  the  middle  lobes  of  the  hemispheres. 
The  space  which  is  included  between  this  layer  of  membrane  and  those 
parts  of  the  base  of  the  brain  which  are  bounded  by  the  optic  commissure 


PIA    MATER.  371 

and  fissures  of  Sylvius  in  front,  and  the  pons  Varolii  behind,  is  termed 
the  anterior  sub-arachnoidean  space.  Another  space  formed  in  a  similar 
manner,  between  the  under  part  of  the  cerebellum  and  the  medulla  oblon- 
gata,  is  the  posterior  sub-arachnoidean  space ;  and  a  third  space,  situated 
over  the  corpora  quadrigemina,  may  be  termed  the  superior  sub-arach- 
noidean space.  These  spaces  communicate  freely  with  each  other,  the 
anterior  and  posterior  across  the  crura  cerebelli,  the  anterior  and  the  supe- 
rior around  the  crura  cerebri,  and  the  latter  and  the  posterior  across  the 
cerebellum  in  the  course  of  the  vermiform  processes.  They  communicate 
also  with  a  still  larger  space  formed  by  the  loose  disposition  of  the  arach- 
noid around  the  spinal  cord,  the  spinal  sub-arachnoidean  space.  The 
whole  of  these  spaces,  with  the  lesser  spaces  between  the  convolutions  of 
the  hemispheres,  constitute  one  large  and  continuous  cavity  which  is  filled 
with  a  limpid,  serous  secretion,  the  sub-arachnoidean  fluid*  a  fluid  which 
is  necessary  to  the  maintenance  and  protection  of  the  cerebro-spinal  mass. 
The  quantity  of  the  sub-arachnoidean  fluid  is  determined  by  the  relative 
size  of  the  cerebro-spinal  axis  and  that  of  the  containing  cavity,  and  is 
consequently  very  variable.  It  is  smaller  in  youth  than  in  old  age,  and 
in  the  adult  has  been  estimated  at  about  two  ounces.  The  visceral  layer 
of  the  arachnoid  is  connected  to  the  pia  mater  by  a  delicate  areolar  tissue, 
which  in  the  sub-arachnoidean  spaces  is  loose  and  filamentous.  The 
serous  secretion  of  the  true  cavity  of  the  arachnoid  is  very  small  in  quan- 
tity as  compared  with  the  sub-arachnoidean  fluid. 

The  arachnoid  does  not  enter  into  the  ventricles  of  the  brain,  as  imagined 
by  Bichat,  but  is  reflected  inwards  upon  the  vense  Galeni  for  a  short  dis- 
tance only,  and  returns  upon  those  vessels  to  the  dura  mater  of  the  tento- 
rium.  It  surrounds  the  nerves  as  they  originate  from  the  brain,  and  forms 
a  sheath  around  them  to  their  point  of  exit  from,  the  skull.  It  is  then  re- 
flected back  upon  the  inner  surface  of  the  dura  mater. 

According  to  Mr.  Rainey,f  vessels,  of  considerable  size,  but  few  in 
number ;  and  branches  of  cranial  nerves  are  found  in  the  arachnoid.  He 
also  describes,  in  this  membrane,  numberless  plexuses  and  ganglia,  which 
he  considers  to  be  analogous  to  those  of  the  sympathetic  nerve.  The  fibres 
proceeding  from  this  source  are  distributed  on  the  arteries  and  nerves  of 
the  cerebro-spinal  axis,  but  particularly  on  the  former. 

Pia  Mater. 

The  Pia  mater  is  a  vascular  membrane  composed  of  innumerable  ves- 
sels held  together  by  a  thin  layer  of  areolar  tissue.  It  invests  the  whole 
surface  of  the  brain,  dipping  into  thie  sulci  between  the  convolutions,  and 
forming  a  fold  in  its  interior  called  velum  interpositum.  It  also  forms  folds 
in  other  situations,  as  in  the  third  and  fourth  ventricles,  and  in  the  longi- 
tudinal fissures  of  the  spinal  cord. 

This  membrane  differs  very  strikingly  in  its  structure  in  different  parts  of 
the  cerebro-spinal  axis.  Thus,  on  the  surface  of  the  cerebrum,  in  contact 
with  the  soft  grey  matter  of  the  brain,  it  is  extremely  vascular,  forming  re- 
markable loops  of  anastomoses  in  the  interspaces  of  the  convolutions,  and 

•  The  presence  of  a  serous  fluid  beneath  the  arachnoid  has  given  rise  to  the  conjec- 
ture that  a  sub-arachnoid  serous  membrane  may  exist  in  that  situation.  Such  a  suppo- 
sition is  quite  unnecessary  to  explain  the  production  of  the  secretion,  since  the  pia 
rnater  is  fully  adequate  to  that  function. 

•J-  Medico-Chirurgical  Transactions,  vol.  29. 


372  CEREBRUM. 

distributing  multitudes  of  minute  straight  vessels  to  the  grey  substance, 
In  the  substantia  perforata,  again,  and  locus  perforatus,  it  gives  off'  tufts 
of  small  arteries,  which  pierce  the  white  matter  to  reach  the  grey  substance 
in  the  interior.  But  upon  the  crura  cerebri,  pons  Varolii,  and  spinal  cord, 
its  vascular  character  seems  almost  lost.  It  has  become  a  dense  fibrous 
membrane,  difficult  to  tear  off,  and  forming  the  proper  sheath  of  the  spina 
cord. 

The  pia  mater  is  the  nutrient  membrane  of  the  brain,  and  derives  it 
bbod  from  the  internal  carotid  and  vertebral  arteries. 

Its  Nerves  are  the  minute  filaments  of  the  sympathetic,  which  accom 
pany  the  branches  of  the  arteries. 

C  EREBRUM. 

The  Cerebrum  presents  on  its  surface  a  number  of  slightly  convex  ele- 
vations, the  convolutions,  (gyri)  which  are  separated  from  each  other  by 
sulci  of  various  depth.*  It  is  divided  superiorly  into  two  hemispheres  by 
the  great  longitudinal  fissure,  which  lodges  the  falx  cerebri,  and  marks 
the  original  development  of  the  brain  by  two  symmetrical  halves. 

Each  hemisphere,  upon  its  under  surface,  admits  of  a  division  into  three 
lobes,  anterior,  middle,  and  posterior.  The  anterior  lobe  rests  upon  the 
roof  of  the  orbit,  and  is  separated  from  the  middle  by  the  fissure  of  Sylvius,  f 
The  middle  lobe  is  received  into  the  middle  fossa?  of  the  base  of  the  skull, 
and  is  separated  from  the  posterior  by  a  slight  impression  produced  by  the 
ridge  of  the  petrous  bone.  The  posterior  lobe  is  supported  by  the  tentorium. 

If  the  upper  part  of  one  hemisphere,  at  about  one-third  from  its  summit, 
be  removed  with  a  scalpel,  a  centre  of  white  substance  will  be  observed, 
surrounded  by  a  narrow  border  of  grey,  wrhich  follows  the  line  of  the  sulci 
and  convolutions,  and  presents  a  zigzag  form.  This  section  from  exhibit- 
ing the  largest  surface  of  medullary  substance  demonstrable  in  a  single 
hemisphere  is  called  centrum  ovale  minus  ;  it  is  spotted  by  numerous  small 
red  points  (puncta  vasculosa)  which  are  produced  by  the  escape  of  blood 
from  the  cut  ends  of  minute  arteries  and  veins. 

Now  separate  carefully  the  two  hemispheres  of  the  cerebrum,  and  a 
broad  band  of  white  substance  (corpus  callosum)  will  be  seen  to  connect 
them ;  it  will  be  seen  also  that  the  surface  of  the  hemisphere  where  it  comes 
in  contact  with  the  corpus  callosum  is  bounded  by  a  large  convolution 
(gyrus  fornicatus)  which  lies  horizontally  on  that  body,  and  may  be  traced 
forwards  and  backwards  to  the  base  of  the  brain,  terminating  by  each  ex- 
tremity at  the  fissure  of  Sylvius.  The  sulcus  between  this  convolution  and 
the  corpus  callosum  has  been  termed,  very  improperly,  the  "  ventricle  of 
the  corpus  callosum,"  and  some  longitudinal  fibres  (striae  longitudinales 
laterales),  which  are  brought  into  view  when  the  convolution  is  raised, 
were  called  by  Reil  the  "  covered  band."  If,  now,  the  upper  part  of  each 
hemisphere  be  removed  to  a  level  with  the  corpus  callosum,  a  large  ex- 
panse of  medullary  matter,  surrounded  by  a  zigzag  line  of  grey  substance 
corresponding  with  the  convolutions  and  sulci  of  the  two  hemispheres,  will 
be  seen ;  this  is  the  centrum  ovale  majus  of  Vieussens. 

*In  estimating  the  surface  of  the  brain,  which,  according  to  Baillarger,  averages  in 
iound  numbers,  670  square  inches,  these  convolutions  and  the  lamime  of  the  cerebellum 
are  supposed  to  be  unfolded. 

•{•James  Dubois,  a  celebrated  professor  of  anatomy  in  Paris,  where  he  succeeded  Vi 
dius  in  1550,  although  known  much  earlier  by  his  works  and  discoveries,  but  particu 
larly  by  his  violence  in  the  defence  of  Galen.  His  name  was  latinised  to  Jacobus  Sylvius. 


LATERAL   VENTRICLES. 


373 


Fig.  169.* 


The  Corpus  callosum  (callosus,  hard) 
is  a  thick  layer  of  medullary  fibres 
passing  transversely  between  the  two 
hemispheres,  and  constituting  their 
great  commissure.  It  is  situated  in  the 
middle  line  of  the  centrum  ovale  ma- 
jus,  but  nearer  the  anterior  than  the 
posterior  part  of  the  brain,  and  termi- 
nates anteriorly  in  a  rounded  border 
(genu),  which  may  be  traced  down- 
wards to  the  base  of  the  brain  in  front 
of  the  commissure  of  the  optic  nerves, 
Posteriorly  it  forms  a  thick  rounded 
fold  (splenium),  which  is  continuous 
with  the  fornix.  The  length  of  the 
corpus  callosum  is  about  four  inches. 

Beneath  the  posterior  rounded  bor- 
der of  the  corpus  callosum  is  the  trans- 
verse fissure  of  the  cerebrum,  which 
extends  between  the  hemispheres  and 

crura  cerebri  from  near  the  fissure  of  Sylvius  on  one  side,  to  the  same 
point  on  the  opposite  side  of  the  brain.  It  is  through  this  fissure  that  the 
pia  mater  communicates  with  the  velum  interpositum.  And  it  was  here 
that  Bichat  conceived  the  arachnoid  to  enter  the  ventricles  ;  hence  it  is 
also  named  the  fissure  of  Bichat. 

Along  the  middle  line  of  the  corpus  callosum  is  the  raphe,  a  linear  de- 
pression between  two  slightly  elevated  longitudinal  bands  (chordae  longi- 
tudinales,  Lancisii);  and,  on  either  side  of  the  raphe,  may  be  seen  the 
linea  transversce,  which  mark  the  direction  of  the  fibres  of  which  the  cor- 
pus callosum  is  composed.  These  fibres  may  be  traced  into  the  hemi- 
spheres on  either  side,  and  they  will  be  seen  to  be  crossed  at  about  an 
inch  from  the  raphe  by  the  longitudinal  fibres  of  the  covered  band  of  Reil. 
Anteriorly  and  posteriorly  the  fibres  of  the  corpus  callosum  curve  into 
their  corresponding  lobes. 

If,  now,  a  superficial  incision  be  made  through  the  corpus  callosum  on 
either  side  of  the  raphe,  two  irregular  cavities  will  be  opened,  which  ex- 
tend from  one  extremity  of  the  hemispheres  to  the  other :  these  are  the 
lateral  ventricles.  To  expose  them  completely,  their  upper  boundary 
should  be  removed  with  the  scissors.  In  making  this  dissection  the  thin 
and  diaphanous  membrane  of  the  ventricles  may  frequently  be  seen. 

LATERAL  VENTRICLES. — Each  lateral  ventricle  is  divided  into  a  central 
cavity,  and  three  smaller  cavities  called  cornua.  The  anterior  cornu 
curves  forwards  and  outwards  in  the  anterior  lobe ;  the  middle  cornu  de- 
scends into  the  middle  lobe  ;  and  the  posterior  cornu  passes  backwards  in 
the  posterior  lobe,  converging  towards  its  fellow  of  the  opposite  side. 
The  central  cavity  is  triangular  in  form,  being  bounded  above  (roof)  by 
the  corpus  callosum  ;  internally  by  the  septum  lucidum,  which  separates 

*  A  section  of  the  brain  showing  the  centrum  ovale  rnajus  and  corpus  callosinr; 
1,  1.  The  anterior  lobes  of  the  brain.  2,2.  The  posterior  lobes.  3,  3.  The  longitudinal 
fissure  for  the  reception  of  the  falx  cerebri.  4,  4.  The  roof  of  the  lateral  ventricles. 
5,  5.  The  genu  of  the  corpus  callosum.  6.  Its  body,  upon  which  the  linese  transversan 
are  seen  7,  7.  The  splenium  corporis  callosi.  8.  The  raphe.  9,  9.  The  striae  longi 
tudinales  laterales,  or  covered  bands  of  Reil. 

32 


Fig.  170« 


374  THALAMUS    OPTICUS. 

it  from  the  opposite  ventricle  ;  and  below  (floor]  by  the  following  parts, 
taken  in  their  order  of  position  from  before  backwards  : — 

Corpus  striatum, 
Tenia  semicircularis, 
Thalamus  opticus, 
Choroid  plexus, 
Corpus  fimbriatum, 
Fornix. 

The  Corpus  striatum  is  named  from 
the  striated  lines  of  white  and  grey 
matter  which  are  seen  upon  cutting  into 
its  substance.  •  It  is  grey  on  the  exte- 
rior, and  of  a  pyriform  shape.  The 
broad  end,  directed  forwards,  rests 
against,  the  corpus  striatum  of  the  op- 
posite side  :  the  small  end,  backwards, 
is  separated  from  its  fellow  by  the  in- 
terposition of  the  thalami  optici.  The 
corpora  striata  are  the  superior  ganglia 
of  the  cerebrum. 

The  Tenia  semicircularis  (tenia,  a 
fillet)  is  a  narrow  band  of  medullary 
substance,  extending  along  the  poste- 
rior border  of  the  corpus  striatum,  and 
serving  as  a  bond  of  connexion  between 
that  body  and  the  thalamus  opticus. 
The  tenia  is  partly  concealed  by  a  large 
vein  (vena  corporis  striati),  which  ter- 
minates in  the  vena  Galeni  of  its  own  side.  The  vein  is  formed  by  small 
vessels  from  the  corpus  striatum  and  thalamus  opticus,  and  is  overlaid  by 
a  yellowish  band,  a  thickening  of  the  lining  membrane  of  the  ventricle. 
This  was  first  noticed  and  described  by  Tarinus,  under  the  name  of  the 
horny  band.  We  may  therefore  term  it  tenia  Tarini.\ 

The  Thalamus  opticus  (thalamus,  a  bed)  is  an  oblong  tody,  having  a 

•  The  lateral  ventricles  of  the  cerebrum.  1,  1.  The  two  hemispheres  cut  down  to  a 
level  with  the  corpus  callosum  so  as  to  constitute  the  centrum  ovale  majus.  The  sur 
face  is  seen  to  be  studded  with  the  small  vascular  points — puncta  vasculosa;  and  sur- 
rounded by  a  narrow  margin  which  represents  the  grey  substance.  2.  A  small  portion 
of  the  anterior  extremity  (genu)  of  the  corpus  callosum.  3.  Its  posterior  boundary 
(splenium)  ;  the  intermediate  portion  forming  the  roof  of  the  lateral  ventricles  has  been 
removed  so  as  to  expose  completely  those  cavities.  4.  A  part  of  the  septum  lucidum, 
showing  an  interspace  between  its  layers — the  fifth  ventricle.  5.  The  anterior  cornu 
of  one  side.  6.  The  commencement  of  the  middle  cornu.  7.  The  posterior  cornu.  8. 
The  corpus  striatum  of  one  ventricle.  9.  The  tenia  semicircularis  covered  by  the  vena 
corporis  stria*  and  tenia  Tarini.  10.  A  small  part  of  the  thalamus  opticus.  11.  The 
dark  fringe-like  body  to  the  left  of  the  numeral  is  the  choroid  plexus.  This  plexus 
communicates  with  that  of  the  opposite  ventricle  through  the  foramen  of  Monro,  or  fo- 
ramen commune  anterius;  a  bristle  is  passed  through  this  opening  (under  figure  4),  and 
its  extremities  are  seen  resting  on  the  corpus  striatum  at  each  side.  The  figure  1 1 
rests  upon  the  edge  of  the  fornix,  on  that  part  of  it  which  is  called  the  corpus  fimbria 
turn.  12.  The  fornix.  13.  The  commencement  of  the  hippocampus  major  descending 
into  the  middle  cornu.  The  rounded  oblong  body  in  the  posterior  cornu  of  the  lateral 
ventricle,  mrectly  behind  the  figure  13,  is  the  hippocampus  minor. 

f  Peter  Tarin,  a  French  anatomist ;  his  work,  entitled  "  Adversaria  Anatomica,"  was 
published  in  1750. 


CHOROID    PLEXUS.  375 

tmn  coating  of  white  substance  on  its  surface ;  it  has  received  its  name 
from  giving  origin  to  one  root  of  the  optic  nerve.  It  is  the  inferior  gan- 
glion of  the  cerebrum.  Part  only  of  the  thalamus  is  seen  in  the  floor  of 
the  lateral  ventricle  ;  we  must,  therefore,  defer  its  further  description  until 
,ve  can  examine  it  in  its  entire  extent. 

The  Choroid  plexus  (xo/£lov)  ^°s,  resembling  the  chorion*)  is  a  vascular 
fringe  extending  obliquely  across  the  floor  of  the  lateral  ventricle,  and 
sinking  into  the  middle  cornu.  Anteriorly,  it  is  small  and  tapering,  and 
communicates  with  the  choroid  plexus  of  the  opposite  ventricle,  through 
a  large  oval  opening,  the  foramen  ofMonro,  or  foramen  commune  ante- 
rius.  This  foramen  may  be  distinctly  seen  by  pulling  slightly  on  the 
plexus,  and  pressing  aside  the  septum  lucidurn  with  the  handle  of  the 
knife.  It.  is  situated  between  the  under  surface  of  the  fornix,  and  the  an- 
terior extremities  of  the  thalami  optici,  and  forms  a  communication  trans- 
versely between  the  lateral  ventricles,  and  perpendicularly  with  the  third 
ventricle. 

The  choroid  plexus  presents  upon  its  surface  a  number  of  minute  vas- 
cular processes,  which  are  termed  villi.  They  are  invested  by  a  very 
delicate  epithelium,  surmounted  by  cilia,  which  have  been  seen  in  active 
movement  in  the  embryo.  In  their  interior  the  plexuses  not  unfrequently 
contain  particles  of  calcareous  matter,  and  they  are  sometimes  covered  by 
small  clusters  of  serous  cysts. 

The  Corpus  fimbriatum  is  a  narrow  white  band,  which  is  situated  im- 
mediately behind  the  choroid  plexus,  and  extends  with  it  into  the  de- 
scending cornu  of  the  lateral  ventricle.  It  is,  in  fact,  the  lateral  thin  edge 
of  the  fornix,  and  being  attached  to  the  hippocampus  major  in  the  de- 
scending horn  of  the  lateral  ventricle,  it  is  also  termed,  terda  hippocampi. 
The  Fornix  is  a  white  layer  of  medullary  substance,  of  which  a  portion 
only  is  seen  in  this  view  of  the  ventricle. 

The  Anterior  cornu  is  triangular  in  its  form,  sweeping  outwards,  and 
terminating  by  a  pofnt  in  the  anterior  lobe  of  the  brain,  at  a  short  distance 
from  its  surface. 

The  Posterior  cornu  or  digital  cavity  curves  inwards,  as  it  extends  back 
into  the  posterior  lobe  of  the  brain,  and  likewise  terminates  near  the  sur- 
face. An  elevation  corresponding  with  a  deep  sulcus  between  two  convo- 
lutions projects  into  the  area  of  this  cornu,  and  is  called  the  hippocampus 
minor. 

The  Middle  or  descending  cornu,  in  descending  into  the  middle  lobe  of 
the  brain,  forms  a  very  considerable  curve,  and  alters  its  direction  several 
times  as  it  proceeds.  Hence  it  is  described  as  passing  backwards  and 
outwards  and  downwards,  and  then  turning  forwards  and  inwards.  This 
complex  expression  of  a  very  simple  curve  has  given  origin  to  a  symbol 
formed  by  the  primary  letters  of  these  various  terras ;  and  by  means  of 
this  the  student  recollects  with  ease  the  course  of  the  cornu,  BODFI.  It  is 
the  largest  of  the  three  cornua,  and  terminates  close  to  the  fissure  of  Syl- 
vius, after  having  curved  around  the  crus  cerebri. 

The  middle  cornu  should  now  be  laid  open,  by  inserting  the  little  finp-ei 
into  its  cavity,  and  making  it  serve  as  a  director  for  the  scalpel  in  cuttnW 
away  the  side  of  the  hemisphere,  so  as  to  expose  it  completely. 

The  Superior  boundary  of  the  middle  cornu  is  formed  by  the  under  sur- 

•  See  the  note  appended  to  the  description  of  the  choroid  coat  of  the  eye-ball 


376  FASCIA    DENTATA. 

face  of  the  thalamus  opticus,  upon  which  are  the  two  projections  calleq 
corpus  geniculatum  internum  and  externum  ;  and  the  inferior  wall  by  the 
various  parts  which  are  sometimes  spoken  of  as  the  contents  of  the  middle 
cornu :  these  are  the — 

Hippocampus  major, 
Pes  hippocampi, 
Pes  accessorius, 
Corpus  fimbriatum, 
Choroid  plexus, 
Fascia  dentata, 
Transverse  fissure. 

The  Hippocampus  major  or  cornu  Jlmmonis,  so  called  from  its  resem- 
blance to  a  ram's  horn,  the  famous  crest  of  Jupiter  Ammon,  is  a  consider- 
able projection  from  the  inferior  wall,  and  extends  the  wrhole  length  of  the 
middle  cornu.  Its  extremity  is  likened  to  the  foot  of  an  animal,  from  its 
presenting  a  number  of  knuckle-like  elevations  upon  the  surface,  and  is 
named  pes  hippocampi.  The  hippocampus  major  is  the  internal  surface 
of  the  convolution  (gyrus  fornicatus)  of  the  lateral  edge  of  the  hemisphere, 
the  convolution  which  has  been  previously  described  as  lying  upon  the 
corpus  callosum  and  extending  downwards  to  the  base  of  the  brain  to 
terminate  at  the  fissure  of  Sylvius.  If  it  be  cut  across,  the  section  will  be 
seen  to  resemble  the  extremity  of  a  convoluted  scroll,  consisting  of  alter- 
nate layers  of  white  and  grey  substance.  The  hippocampus  major  is  con- 
tinuous superiorly  with  the  fornix  and  corpus  callosum,  deriving  from  the 
latter  its  medullary  layer. 

The  Pes  accessorius  is  a  swelling  somewhat  resembling  the  hippocampus 
major,  but  smaller  in  size ;  it  is  situated  on  the  outer  wall  of  the  cornu, 
and  is  frequently  absent. 

The  Corpus  fimbriatum  (tenia  hippocampi)  is  the  narrow  w^hite  band 
which  is  prolonged  from  the  central  cavity  of  the  ventricle,  and  is  attached 
along  the  inner  border  of  the  hippocampus  major.  It  is  lost  inferiorly  on 
the  hippocampus. 

Fascia  dentata: — if  the  corpus  fimbriatum  be  carefully  raised,  a  narrow 
serrated  band  of  grey  substance,  the  margin  of  the  grey  substance  of  the 
middle  lobe,  will  be  seen  beneath  it ;  this  is  the  fascia  dentata.  Beneath 
the  corpus  fimbriatum  will  be  likewise  seen  the  transverse  fissure  of  the 
brain,  which  has  been  before  described  as  extending  from  near  the  fissure 
of  Sylvius  on  one  side,  across  to  the  same  point  on  the  opposite  side  of 
the  brain.  It  is  through  this  fissure  that  the  pia  mater  communicates  with 
the  chor oid  plexus,  and  the  latter  obtains  its  supply  of  blood.  The  fissure 
is  bounded  on  one  side  by  the  corpus  fimbriatum,  and  on  the  other  by  the 
under  surface  of  the  thalamus  opticus. 

The  internal  boundary  of  the  lateral  ventricle  is  the  septum  lucidum. 
This  septum  is  thin  and  semi-transparent,  and  consists  of  two  lamincs  of 
cerebral  substance  attached  above  to  the  under  surface  of  the  corpus  cal- 
losura  at  its  anterior  part,  and  below  to  the  fornix.  Between  the  two 
layejs  is  a  narrow  space,  the  fifth  ventricle,  which  is  lined  by  a  prr-per 
membrane.  The  fifth  ventricle  may  be  shown,  by  snipping  through  the 
septum  lucidum  transversely  with  the  scissors. 

The  corpus  callosum  should  now  be  cut  across  towards  its  anterior  ex- 


FOR.MX.  377 

tremitj  t  and  the  two  ends  carefully  dissected  away.  The  anterior  portion 
will  be  retained  only  by  the  septum  lucidum,  but  the  posterior  will  be 
found  incorporated  with  the  white  layer  beneath,  which  is  the  fornix. 

FORNIX. —  The  fornix  (arch)  is  a  triangular  lamina  of  white  substance, 
broad  behind,  and  extending  into  each  lateral  ventricle  :  narrow  in  front, 
where  it  terminates  in  two  crura,  which  arch  downwards  to  the  base  of 
the  brain.  The  two  crura  descend  in  a  curved  direction  to  the  base  of 
the  brain,  embedded  in  grey  substance,  in  the  lateral  walls  of  the  third 
ventricle,  and  lying  directly  behind  the  anterior  commissure.  At  the  base 
of  the  brain  they  make  a  sudden  curve  upon  themselves  and  constitute  the 
corpora  albicantia,  from  which  they  may  be  traced  upwards  to  their  origin 
in  the  thalami  optici.  Opening  transversely  beneath  these  two  crura,  just 
as  they  are  about  to  arch  downwards,  is-  the  foramen  of  communication 
between  the  lateral  and  the  third  ventricles,  the  foramen  of  Monro ;  or 
foramen  commute  anterius.  The  choroid  plexuses  communicate,  and  the 
veins  of  the  corpora  striata  pass  through  this  opening. 

The  lateral  thin  edges  of  the  fornix  are  continuous  posteriorly  with  the 
concave  border  of  the  hippocampus  major  at  each  side,  and  form  the  nar- 
row white  band  called  corpus  jimbriatum  (posterior  crus  of  the  fornix). 
In  the  middle  line  the  fornix  is  continuous  with  the  corpus  callosum,  and 
at  each  side  with  the  hippocampus  major  and  minor.  Upon  the  under 
surface  of  the  fornix  towards  its  posterior  part,  some  transverse  lines  are 
seen  passing  between  the  diverging  corpora  fimbriata :  this  appearance  is 
termed  the  lyra  (corpus  psalloides),  from  a  fancied  resemblance  to  the 
strings  of  a  harp. 

The  fornix  may  now  be  removed  by  dividing  it  across  anteriorly,  and 
turning  it  backwards,  at  the  same  time  separating  its  lateral  connexions 
with  the  hippocampi.  If  the 

student  examine  its  under  sur-  Fis-  171-* 

face,  he  will  perceive  the  lyra 
above  described. 

Beneath  the  fornix  is  the 
velum  interpositum,  a  duplica- 
ture  of  pia  mater  introduced 
into  the  interior  of  the  brain, 
through  the  transverse  fissure. 
The  velum  is  continuous  at 
each  side  with  the  choroid 
plexus,  and  contains  in  its  in- 
ferior layer  two  large  veins 
(the  vena  Galeni]  which  re- 

*  The  mesial  surface  of  a  longitudinal  section  of  the  brain.  The  incisior.  has  been 
carried  along  the  middle  line;  between  the  two  hemispheres  of  the  cerebrum,  and 
through  the  middle  of  the  cerebellum  and  medulla  oblongata.  1.  The  inner  surface  of 
the  left  hemisphere.  2.  The  divided  surface  of  the  cerebellum,  showing  the  arbor  vitce. 
3.  The  medulla  oblongata.  4.  The  corpus  callosum  curving  downwards  in  front  to  ter- 
minate at  the  base  of  the  brain,  and  rounded  behind  to  become  continuous  with  5,  the 
fornix.  6.  One  of  the  crura  of  the  fornix  descending  to  7,  one  of  the  corpora  albicantia. 
8.  The  septum  lucidum.  9.  The  velum  interpositum,  communicating  with  the  pia  mater 
of  the  convolutions  through  the  fissure  of  Bich&t.  10.  Section  of  the  middle  commissure 
situated  in  the  third  ventricle.  11.  Section  of  the  anterior  commissure.  12.  Section  o.' 
the  posterior  commissure;  the  commissure  is  somewhat  above  and  to  the  left  of  the 
numeral.  The  interspace  between  10  and  11  is  the  foramen  commune  anterius,  in 
•which  the  crus  of  the  fornix  (C)  is  situated.  The  interspace  between  10  and  12  is  Um 

32* 


,'{78  THALAMI    OPTICI — THIRD   VENTRICLE. 

ceive  the  blood  from  the  corpora  striata  and  choroid  plexuses,  and  termi- 
nate posteriorly,  after  uniting  into  a  single  trunk,  in  the  straight  sinus. 
Upon  the  under  surface  of  the  velum  interpositum  are  two  fringe-like 
bodies,  which  project  into  the  third  ventricle.  These  are  the  choroid 
plexuses  of  the  third  ventricle  ;  posteriorly  these  fringes  enclose  the  pineal 
gland. 

If  the  velum  interpositum  be  raised  and  turned  back,  an  operation 
which  must  be  conducted  with  care,  particularly  at  its  posterior  part, 
where  it  invests  the  pineal  gland,  the  thalami  optici  and  the  cavity  of  the 
third  ventricle  will  be  brought  into  view. 

THALAMI  OPTICI.  —  The  thalami  optici  are  two  oblong,  square-shaped 
bodies,  of  a  white  colour  superficially,  inserted  between  the  two  diverging 
portions  of  the  corpora  striata.  In  the  middle  line  a  fissure  exists  between 
them,  which  is  called  the  third  ventricle.  Posteriorly  and  inferiorly,  they 
form  the  superior  wall  of  the  descending  cornu,  and  present  two  rounded 
elevations  called  corpus  geniculatum  externum  and  internum.  The  corpus 
geniculatum  externum  is  the  larger  of  the  two,  and  of  a  greyish  colour ;  it 
is  the  principal  origin  of  the  optic  nerve.  Anteriorly,  the  thalami  are  con- 
nected with  the  corpora  albicantia  by  means  of  two  white  bands,  which 
appear  to  originate  in  the  white  substance  uniting  the  thalami  to  the  cor- 
pora striata.  Externally  they  are  in  relation  with  the  corpora  striata  and 
hemispheres.  In  their  interior  the  thalami  are  compiled  of  white  fibres 
mixed  with  grey  substance.  They  are  essentially  the  inferior  ganglia  of 
the  cerebrum. 

THIRD  VENTRICLE.  —  The  third  ventricle  is  the  fissure  between  the  two 
thalami  optici.  It  is  bounded  above  by  the  under  surface  of  the  velum 
interpositum,  from  which  are  suspended  the  choroid  plexuses  of  the  third 
ventricle.  Its  floor  is  formed  by  the  grey  substance  of  the  anterior  termi- 
nation of  the  corpus  callosum,  called  lamina  cinerea,  the  tuber  cinereum, 
corpora  albicantia,  and  locus  perforatus.  Laterally  it  is  bounded  by  the 
thalami  optici ;  anteriorly  by  the  anterior  commissure  and  crura  of  the 
fornix  ;  and  posteriorly  by  the  posterior  commissure  and  the  iter  a  tertio 
aa  quartum  ventriculum.  The  third  ventricle  is  crossed  by  three  com- 
missures, anterior,  middle,  and  posterior;  and  between  these  are  two 
spaces,  called  foramen  commune  anterius  and  foramen  commune  posterius. 

The  interior  commissure  is  a  small  rounded  white  cord,  which  enters 
the  corpus  striatum  at  either  side,  and  spreads  out  in  the  substance  of  the 
hemispheres;  the  middle,  or  soft  commissure  consists  of  grey  matter, 
which  is  continuous  with  the  grey  lining  of  the  ventricle,  it  connects  the 
adjacent  sides  of  the  thalami  optici ;  the  posterior  commissure,  smaller  than 
the  anterior,  is  a  rounded  white  cord,  connecting  the  two  thalami  optici 
posteriorly. 

The  space  between  the  anterior  and  middle  commissure  is  called  the 
foramen  commune  anterius,  and  is  that  to  which  Monro  has  given  his 
name  (foramen  of  Monro).  It  is  the  medium  of  communication  between 

foramen  commune  posterius.  13.  The  corpora  quadrigemina,  upon  which  is  seen  rest- 
ing the  pineal  gland,  14.  15.  The  iter  a  tertio  ad  quartum  ventriculum,  or  aqueduct  of 
Sylvius.  16.  The  fourth  ventricle.  17.  The  pons  Varolii,  through  which  are  seen  pass- 
ing the  diverging  fibres  of  the  corpora  pyramidalia.  18.  The  crus  cerebri  of  the  left 
side,  with  the  third  nerve  arising  from  it.  19.  The  tuber  cinereum,  from  which  pro- 
jects the  infundibulum,  having  the  pituitary  gland  appended  to  its  extremity.  20.  One 
of  the  optic  nerves.  21.  The  left  olfactory  nerve  terminating  anteriorly  in  a  rounded 


FOURTH    VENTRICLE.  379 

the  lateral  and  third  ventricles,  and  it  transmits  superiorly  the  choroid 
plexus  and  the  vena2  corporum  striatorum.  The  foramen  commune  ante- 
rius  is  also  termed,  iter  ad  infundibulum,  from  leading  downwards  to  the 
funnel-shaped  cavity  of  the  infundibulum.  The  crura  of  the  fornix  are 
embedded  in  the  lateral  walls  of  the  foramen  commune,  and  are  concealed 
from  view  in  this  situation  by  the  layer  of  grey  substance  which  lines  the 
interior  of  the  third  ventricle.  If  the  crura  be  slightly  separated,  the  an- 
terior commissure  will  be  seen  immediately  in  front  of  them,  crossing  from 
one  corpus  striatum  to  the  other.  The  space  between  the  middle  and 
posterior  commissure  is  the  foramen  commune  posterius  ;  it  is  much  shal 
lower  than  the  preceding,  and  is  the  origin  of  a  canal,  the  aqueduct  of 
Sylvius  or  iter  a  tertio  ad  quartum  ventriculum,  which  leads  backwards 
beneath  the  posterior  commissure  and  through  the  base  of  the  corpora 
quadrigemina  to  the  upper  part  of  the  fourth  ventricle. 

CORPORA  QUADRIGEMINA. — The  corpora  quadrigemina,  or  optic  lobes, 
are  situated  immediately  behind  the  third  ventricle  and  posterior  commis- 
sure ;  and  beneath  the  posterior  border  of  the  corpus  caliosum.  They 
form,  indeed,  at  this  point,  the  inferior  boundary  of  the  transverse  fissure 
of  the  hemispheres,  the  fissure  of  Bichat.  The  anterior  pair  of  these  bodies 
are  grey  in  colour,  and  are  named  nates  :  the  posterior  pair  are  white  and 
much  smaller  than  the  anterior ;  they  are  termed  testes.  From  the  nates 
on  each  side  may  be  traced  a  rounded  process  (brachium  anterius)  which 
passes  obliquely  outwards  into  the  thalamus  opticus ;  and  from  the  testis 
a  similar  but  smaller  process  (brachium  posterius)  which  has  the  same 
destination.  The  corpus  geniculatum  internum  lies  in  the  interval  of 
these  two  processes  where  they  enter  the  thalarnus,  and  behind  the  bra- 
chium posterius  is  a  prominent  band  (laqueus)  which  marks  the  course  of 
the  superior  division  of  the  fasciculus  olivaris.  The  corpora  quadrigemina 
are  perforated  longitudinally  through  their  base  by  the  aqueduct  of  Syl- 
vius ;  they  are  covered  in  partly  by  the  pia  mater  and  partly  by  the  velum 
interpositum,  and  the  nates  form  the  base  of  support  of  the  pineal  gland. 

PINEAL  GLAND. — The  pineal  gland  is  a  small  reddish  grey  body  of  a 
conical  form  (hence  its  synonym  conarium),  situated  on  the  anterior  part 
of  the  nates  and  invested  by  a  duplicature  of  pia  mater  derived  from  the 
under  part  of  the  velum  interpositum.  The  pineal  gland,  when  pressed 
between  the  fingers  is  found  to  contain  a  gritty  matter  (acervulus)  com- 
posed chemically  of  phosphate  and  carbonate  of  lime,  and  is  sometimes 
hollow  in  the  interior.  It  is  connected  to  the  brain  by  means  of  two  me- 
dullary cords  called  peduncles  and  a  thin  lamina  derived  from  the  posterior 
commissure ;  the  peduncles  of  the  pineal  gland  are  attached  to  the  thalami 
optici,  and  may  be  traced  along  the  upper  and  inner  margin  of  those 
bodies  to  the  crura  of  the  fornix  with  which  they  become  blended.  From 
the  close  connexion  subsisting  between  the  pia  mater  and  the  pineal  gland, 
and  the  softness  of  texture  of  the  latter,  the  gland  is  liable  to  be  torn  away 
in  the  removal  of  the  pia  mater. 

Behind  the  corpora  quadrigemina  is  the  cerebellum,  and  beneath  the 
cerebellum  the  fourth  ventricle.  The  student  must  therefore  divide  the 
cerebellum  down  to  the  fourth  ventricle,  and  turn  its  lobes  aside  to  ex- 
amine that  cavity. 

FOURTH  VENTRICLE. — The  fourth  ventricle  (sinus  rhomboidalis)  is  the 
ventricle  of  the  medulla  oblongata,  upon  the  posterior  surface  of  which, 
and  of  the  pons  Varolii,  it  is  placed.  It  is  a  lozenge-shaped  cavity, 


380  LINING   MEMBRANE    OF   THE   VENTRICLES. 

bounded  on  each  side  by  a  thick  cord  passing  between  the  cerebellum  and 
corpora  quadrigemina,  called  the  processus  e  cerebello  ad  testes,  and  by  the 
corpus  restiforme.  It  is  covered  in  behind  by  the  cerebellum,  and  by  a 
thin  lamella  of  medullary  substance,  stretched  between  the  two  processus 
e  cerebello  ad  testes,  termed  the  valve  of  Vieussens* 

That  portion  of  the  cerebellum  which  forms  the  posterior  boundary  of 
the  fourth  ventricle,  presents  four  small  prominences  or  lobules,  and  a  thin 
layer  of  medullary  substance,  the  velum  medullare  posterius.  Of  the 
lobules  two  are  placed  in  the  middle  line,  the  nodulus  and  uvula,  the  for- 
mer being  before  the  latter ;  the  remaining  two  are  named  amygdala,  or 
tonsils,  and  are  situated  one  on  either  side  of  the  uvula.  They  all  project 
into  the  cavity  of  the  fourth  ventricle,  and  the  velum  medullare  posterius 
is  situated  in  front  of  them.  The  valve  of  Vieussens,  or  velum  medullare 
anterius,  is  an  extremely  thin  lamella  of  medullary  substance,  prolonged 
from  the  white  matter  of  the  cerebellum  to  the  testes,  and  attached  on 
each  side  to  the  processus  e  cerebello  ad  testes.  This  lamella  is  overlaid 
for  a  short  distance  by  a  thin,  transversely-grooved  lobule  of  grey  sub- 
stance (linguetta  laminosa)  derived  from  the  anterior  border  of  the  cere- 
bellum, and  its  junction  with  the  testes  is  strengthened  by  a  narrow  slip 
given  off  by  the  commissure  of  those  bodies,  thefrcenulum  veli  medullans 
anterioris.  The  anterior  wall,  or  Jloor  of  the  fourth  ventricle  is  formed 
by  two  slightly  convex  bodies,  processus  teretes  or  posterior  pyramids, 
separated  by  a  longitudinal  groove  which  is  continuous  inferiorly  with  the 
fissura  longitudinalis  posterior  of  the  spinal  cord.  The  processus  teretes 
are  crossed  transversely  by  several  white  and  grey  fasciculi  (lineee  trans- 
verscB)  the  origin  of  the  auditory  nerves.  And  upon  the  lower  part  of  the 
floor  of  this  ventricle  is  an  impression  resembling  the  point  of  a  pen,  and 
hence  named  calamus  scriptorius ;  the  lateral  boundaries  of  the  calamus 
are  the  processus  clavati  of  the  posterior  median  columns  of  the  spinal 
cord.  Move,  the  fourth  ventricle  is  bounded  by  the  corpora  quadrige- 
mina and  aqueduct  of  Sylvius ;  and  below  by  a  layer  of  pia  mater  and 
arachnoid,  called  the  valve  of  the  arachnoid.  It  is  by  rupture  of  this  lat- 
ter that  a  communication  is  established  between  the  ventricles  of  the  brain 
and  the  sub-arachnoidean  space.  Within  the  fourth  ventricle  and  lying 
against  the  uvula  and  tonsils  are  two  small  vascular  fringes  formed  by  the 
pia  mater,  the  choroid  plexuses  of  the  fourth  ventricle.  The  fourth  ven- 
tricle is  lined  by  grey  matter  derived  from  the  interior  of  the  spinal  cord, 
the  grey  matter  being  partly  concealed  by  a  thin  expansion  of  white  sub- 
stance. 

LINING    MEMBRANE    OF    THE    VENTRICLES. 

The  lining  membrane  of  the  ventricles  is  a  serous  layer  distinct  from  the 
arachnoid  ;  it  lines  the  whole  of  the  interior  of  the  lateral  ventricles,  and 
is  connected  above  and  below  with  the  attached  border  of  the  choroid 
plexus,  so  as  to  exclude  all  communication  between  the  ventricles  and 
the  exterior  of  the  brain.  From  the  lateral  ventricles  it  is  reflected  through 
the  foramen  of  Monro  on  each  side,  into  the  third  ventricle,  which  it  in- 
vests throughout.  From  the  third  it  is  conducted  into  the  fourth  veuiricle, 
through  the  iter  a  tertio  ad  quartum  veritriculum,  and  lines  its  interior,  to- 

•  Raymond  Vieussens,  a  great  discoverer  in  the  anatomy  of  the  brain  and  nervous 
•ystem.  His  "  Neurog-aphia  Universalis"  was  published  at  Lyons,  in  1685. 


CEREBELLUM.  381 

gether  -with  a  layer  of  pia  mater  which  forms  its  inferior  boundary.  In 
this  manner  a  perfect  communication  is  established  between  all  the  ven- 
tricles, with  the  exception  of  the  fifth,  which  has  its  own  proper  membrane. 
It  is  this  membrane  which  gives  them  their  polished  surface,  and  transudes 
the  secretion  which  moistens  their  interior.  When  the  fluid  accumulates 
to  an  unnatural  degree,  it  may  then  break  down  this  layer  and  the  layer 
of  pia  mater  at  the  bottom  of  the  fourth  ventricle,  and  thus  make  its  way 
into  the  sub-arachnoidean  space ;  but  in  the  normal  condition  it  is  doubt- 
ful whether  a  communication  exists  between  the  interior  of  the  ventricles 
and  the  serous  cavity  of  the  sub-arachnoidean  space. 

CEREBELLUM. 

The  Cerebellum  (figs.  171,  172,  173),  seven  times  smaller  than  the 
cerebrum,  is  situated  beneath  the  posterior  lobes  of  the  latter,  being  lodged 
in  the  posterior  fossa  of  the  base  of  the  cranium,  and  protected  from  the 
superincumbent  pressure  of  the  cerebrum  by  the  tentorium  cerebelli.  Like 
the  cerebrum,  it  is  composed  of  grey  and  white  substance,  the  former 
occupying  the  surface,  the  latter  the  interior,  and  its  surface  is  formed  of 
parallel  lamellae  separated  by  sulci,  and  here  and  there  by  deeper  sulci. 
In  form,  the  cerebellum  is  oblong  and  flattened,  its  greater  diameter  being 
from  side  to  side,  its  two  surfaces  looking  upwards  and  downwards,  and 
its  borders  being  anterior,  posterior,  and  lateral.  In  consideration  of  its 
shape  the  cerebellum  admits  of  a  division  into  two  hemispheres,  into  cer- 
tain prominences  termed  processes  and  lobules,  and  into  certain  divisions 
of  its  substance  called  lobes,  formed  upon  the  hemispheres  by  the  deeper 
sulci  above  referred  to.  The  two  hemispheres  are  separated  from  each 
other  on  the  upper  surface  of  the  cerebellum  by  a  longitudinal  ridge  which 
is  termed  the  superior  vermiform  process,  and  which  forms  a  commissure 
between  them.  On  the  anterior  border  of  the  organ  there  is  a  semilunar 
notch,  indsura  cerebelli  anterior,  which  encircles  the  corpora  quadrigemina 
posteriorly.  On  the  posterior  border  there  is  another  notch,  indsura  cere- 
belli posterior,  which  receives  the  upper  part  of  the  falx  cerebelli ;  and  on 
the  under  surface  of  the  cerebellum  is  a  deep  fissure  corresponding  with 
the  medulla  oblongata,  and  termed  the  vallecula  (valley). 

Each  hemisphere  of  the  cerebellum  is  divided  by  means  of  a  fissure 
(sulcus  horizontalis)  which  runs  along  its  free  border,  into  an  upper  and  a 
lower  portion,  and  upon  each  of  these  portions  certain  lobes  are  marked 
out.  Thus  on  the  upper  portion  there  are  two  such  lobes  separated  by  a 
sulcus,  somewhat  more  strongly  marked  than  the  rest,  and  extending 
deeper  into  the  substance  of  the  cerebellum ;  they  are  the  lobus  superior 
anterior  and  lobus  superior  posterior.  Upon  the  under  portion  of  the 
hemisphere  there  are  three  such  lobes,  namely,  lobus  inferior  anterior, 
medius,  and  posterior,  and  two  additional  ones  of  peculiar  form,  the  lobus 
inferior  internus  or  tonsil,  and  the  Jlocculus.  The  tonsil  (amygdala)  is 
situated  on  the  side  of  the  vallecula,  and  projects  into  the  fourth  ventricle. 
The  flocculus  or  pneumogastric  lobule,  long  and  slender,  extends  from 
the  side  of  the  vallecula  around  the  corpus  restiforme  to  the  cms  cerebelli, 
lying  behind  the  filaments  of  the  eighth  pair  of  nerves. 

The  commissure  between  the  two  hemispheres  is  termed  the  worm 
'vermis),  that  portion  of  the  worm  which  occupies  the  upper  surface  of 
the  cerebellum  as  far  back  as  the  horizontal  fissure  being  the  processus 


382  BASE    OF   THE   BRAIN. 

vermiformis  superior,  and  that  which  is  lodged  within  the  vallecula  being 
the  processus  vermiformis  inferior.  The  superior  vermiform  process  is  a 
prominent  longitudinal  ridge,  extending  from  the  incisura  anterior  to  the 
incisura  posterior  cerebelli.  In  imitation  of  the  hemispheres,  it  is  divided 
into  lobes,  of  which  three  have  received  names,  namely,  the  lobulus  cer> 
tralis,  which  is  a  small  lobe  situated  in  the  incisura  anterior ;  the  monti- 
culus  cerebelli,  a  longer  lobe,  having  its  peak  and  declivity ;  and  a  small 
lobe  near  the  incisura  posterior,  the  commissura  simplex.  The  lobes  of 
the  inferior  vermiform  process  are  four  in  number,  namely, — the  commis- 
sura brevis,  situated  in  the  incisura  posterior,  below  the  horizontal  fissure  ; 
the  pyramid,  a  small,  obtusely-pointed  eminence ;  a  larger  prominence, 
the  uvula,  situated  between  the  tonsils,  and  connected  with  them  by  means 
of  a  commissure  ;  and  in  front  of  the  uvula,  the  nodulus.  In  front  of  the 
nodulus  is  a  thin  lamina  of  medullary  substance,  consisting  of  a  central 
and  two  lateral  portions,  the  velum  medullare  posterius  (valvula  Tarini), 
and  between  this  velum  in  front,  and  the  nodulus  and  uvula  behind,  is  a 
deep  fossa  which  is  known  as  the  swallow^s  nest  (nidus  hirundinis).  The 
velum  medullare  anterius  is  the  valve  of  Vieussens,  described  with  the 
fourth  ventricle ;  both  these  vela  proceed  from  the  same  point  in  the  roof 
of  that  ventricle,  and  separate  from  each  other  at  an  angle,  the  one  passing 
obliquely  forwards,  the  other  obliquely  backwards. 

When  a  vertical  incision  is  made  into  the  cerebellum,  that  appearance 
is  seen  which  has  been  denominated  arbor  vitce  cerebelli  ;  the  white  sub- 
stance in  the  centre  of  such  a  section  resembles  the  trunk  of  a  tree,  from 
which  branches  are  given  off,  and  from  the  branches  branchlets  and  leaves, 
the  two  latter  being  coated  by  a  moderately  thick  and  uniform  layer  of 
grey  substance.  If  the  incision  be  made  somewhat  nearer  the  commissure 
than  to  the  lateral  border  of  the  organ,  a  yellowish  grey  dentated  line,  en- 
closing medullary  substance  traversed  by  the  openings  of  numerous  vessels, 
will  be  seen  in  the  centre  of  the  white  substance.  This  is  the  ganglion 
of  the  cerebellum,  the  corpus  rhomboideum  or  dentatum,  from  which  the 
peduncles  of  the  cerebellum  proceed.  The  grey  line  is  dense  and  horny 
in  structure,  and  is  the  cut  edge  of  a  thin  capsule,  open  towards  the 
medulla  oblongata. 

The  cerebellum  is  associated  with  the  rest  of  the  encephalon  by  means 
of  three  pairs  of  rounded  cords  or  peduncles,  superior,  middle,  and  infe- 
rior. The  superior  peduncles,  or  processus  e  cerebello  ad  testes,  proceed 
from  the  cerebellum  forwards  and  upwards  to  the  testes,  in  which  they  are 
lost.  They  form  the  anterior  part  of  the  lateral  boundaries  of  the  fourth 
ventricle,  and  give  attachment  by  their  inner  borders  to  the  valve  of 
Vieussens,  which  is  stretched  between  them.  At  their  junction  with  the 
testes  they  are  crossed  by  the  fourth  pair  of  nerves.  The  middle  pedun- 
cles, or  crura  cerebelli  ad  pontem,  the  largest  of  the  three,  issue  from  the 
cerebellum  through  the  anterior  extremity  of  the  sulcus  horizontalis,  and 
are  lost  in  the  pons  Varolii.  The  inferior  peduncles,  or  crura  ad  medul- 
lam  oblongatam,  are  the  corpora  restiformia  which  descend  to  the  poste- 
rior part  of  the  medulla  oblongata,  and  form  the  inferior  portion  of  the 
lateral  boundaries  of  the  fourth  ventricle. 

BASE     OF     THE     BRAIN. 

The  student  should  now  prepare  to  study  the  base  of  the  brain :  for  this 
ourpose  the  organ  should  be  turned  upon  its  incised  surface ;  and  if  the 


BASE    OF    THE    BRAIN.  383 

dissection  have  hitherto  been  conducted  with  care,  he  will  find  the  base 
perfectly  uninjured.  The  arachnoid  membrane,  some  parts  of  the  pia 
mater,  and  the  circle  of  Willis,  must  be  carefully  cleared  away,  in  order 
vo  expose  all  the  parts  to  be  examined.  These  he  will  find  arranged  in 
b?  following  order  from  before  backwards: — 

Longitudinal  fissure,  Infundibulum, 

Olfactory  nerves,  Corpora  albicantia, 

Fissure  of  Sylvius,  Locus  perforatus, 

Substantia  perforata,  Crura  cerebri, 

Commencement  of  the  trans-  Pons  Varolii, 

verse  fissure,  Crura  cerebelli, 

Optic  commissure,  Medulla  oblongata. 
Tuber  cinereum, 

The  Longitudinal  fissure  is  the  space  separating  the  two  hemispheres: 
it  is  continued  downwards  to  the  base  of  the  brain,  and  divides  the  two 
anterior  lobes.  In  this  fissure  the  anterior  cerebral  arteries  ascend  towards 
the  corpus  callosum ;  and,  if  the  two  lobes  be  slightly  drawn  asunder,  the 
anterior  border  (genu)  of  the  corpus  callosum  will  be  seen  descending  to 
the  base  of  the  brain.  Arrived  at  the  base  of  the  brain,  the  corpus  callo- 
sum terminates  by  a  concave  border,  which  is  prolonged  to  the  commis- 
sure of  the  optic  nerves  by  a  thin  layer  of  grey  substance,  the  lamina 
cinerea.  The  lamina  cinerea  is  the  anterior  part  of  the  inferior  boundary 
of  the  third  ventricle.  On  each  side  of  the  lamina  cinerea  the  corpus  cal- 
losum is  continued  into  the  substantia  perforata  and  crura  cerebri,  and 
upon  the  latter  forms  a  narrow  medullary  band  lying  externally  to,  and 
slightly  overlapping  the  optic  tract,  the  medulla  innominata. 

Upon  the  under  surface  of  each  anterior  lobe,  on  either  side  of  the  lon- 
gitudinal fissure,  is  the  olfactory  nerve,  with  its  bulb. 

The  Fissure  of  Sylvius  bounds  the  anterior  lobe  posteriorly,  and  sepa- 
rates it  from  the  middle  lobe ;  it  lodges  the  middle  cerebral  artery.  If 
this  fissure  be  followed  outwards,  a  small  isolated  cluster  of  five  or  six 
convolutions  will  be  observed ;  these  constitute  the  island  of  Reil,  The 
island  of  Reil,  together  with  the  substantia  perforata,  form  the  base  of  the 
corpus  striatura. 

The  Substantia  perforata  is  a  triangular  plane  of  white  substance,  situ- 
ated at  the  inner  extremity  of  the  fissure  of  Sylvius.  It  is  named  perfo- 
rata from  being  pierced  by  a  number  of  openings  for  small  arteries,  which 
enter  the  brain  in  this  situation  to  supply  the  grey  substance  of  the  corpus 
striatum. 

Passing  backwards  on  each  side  beneath  the  edge  of  the  middle  lobe, 
is  the  commencement  of  the  great  transverse  fissure,  which  extends  beneath 
the  hemisphere  of  one  side  to  the  same  point  on  the  opposite  side.  A 
probe  passed  into  this  fissure  between  the  crus  cerebri  and  middle  lobe 
would  enter  the  middle  cornu  of  the  lateral  ventricle. 

The  Optic  commissure  is  situated  on  the  middle  line ;  it  is  the  point  of 
communication  between  the  two  optic  nerves. 

The  Tuber  cinereum  is  an  eminence  of  grey  substance  situated  immedi- 
ately behind  the  optic  commissure,  and  in  front  of  the  corpora  mammn- 
laria.  From  its  centre  there  projects  a  small  conical  body  of  grey  sub- 
stance,  apparently  a  prolongation  of  the  tuber  cinereum,  the  infundibulum 
The  infundibulum  is  hollow  in  its  interior,  enclosing  a  short  caecal  canal 


384 


BASE    OF    THE    BRAIN. 


Fig.  172.* 


which  communicates  with  the  cavity  of  the  third  ventricle ;  and  below  the 
termination  of  the  canal,  the  conical  process  becomes  connected  with  the 
pituitary  gland.  The  infundibulum  and  tuber  cinereum  form  part  of  the 
floor  of  the  third  ventricle. 

The  Pituitary  gland  (hypophysis  cerebri),  is  a  small,  flattened,  reddish- 
grey  body  situated  in  the  sella  turcica,  and  closely  retained  in  that  situation 
by  the  dura  mater  and  arachnoid.  It  consists  of  two  lobes,  closely  pressed 
together,  the  anterior  lobe  being  the  larger  of  the  two,  and  oblong  in  shape, 
the  posterior  round.  Both  lobes  are  connected  with  the  infundibulum, 
but  the  latter  is  so  soft  in  texture  as  to  be  generally  torn  through  in  the 
removal  of  the  brain.  Indeed,  for  the  purposes  of  the  student,  it  is  better 
to  effect  this  separation  with  the  knife,  and  leave  the  pituitary  body  in  situ, 
to  be  examined  with  the  base  of  the  cranium. 

The  Corpora  albicantia  (mammillaria,  pisiformia,  bulbi  fornicis)  are  two 
white  convex  bodies,  having  the  shape  and  size  of  peas,  situated  behind 
the  tuber  cinereum,  and  between  the  crura  cerebri.  They  are  a  part  of 
the  crura  of  the  fornix,  which,  after  their  origin  from  the  thalami  optici, 
descend  to  the  base  of  the  brain,  and  making  a  sudden  curve  upon  them- 
selves previously  to  their  ascent  to  the  lateral  ventricles,  constitute  the  cor- 
pora albicantia.  "When  divided  by  section,  these  bodies  will  be  found  to 
be  composed  of  a  capsule  of  white  substance,  containing  grey  matter,  the 
grey  matter  of  the  two  corpora  being  connected  by  means  of  a  commissure. 

The  Locus  perforatus  is  a  layer 
of  whitish-grey  substance,  connect- 
ed in  front  with  the  corpora  albi- 
cantia, behind  with  the  pons  Varo- 
lii,  and  on  each  side  with  the  crura 
cerebri,  between  which  it  is  situated. 
It  is  perforated  by  several  thick  tufts 
of  arteries,  which  are  distributed 
to  the  thalami  optici  and  third  ven- 
tricle, of  wrhich  latter  it  assists  in 
forming  the  floor.  It  is  sometimes 
called  the  pons  Tarini. 

The  Crura  cerebri  are  two  thick 
white  cords,  which  issue  from  the 
anterior  border  of  the  pons  Varolii, 
and  diverge  to  each  side  to  enter 
the  thalami  optici.  By  their  outer 
side  the  crura  cerebri  are  continu- 
ous with  the  corpora  quadrigemina, 
and,  above,  they  constitute  the 
lo\ver  boundary  of  the  aqueduct  of 

*  The  under  surface  or  base  of  the  brain.  1.  The  anterior  lobe  of  one  hemisphere 
of  the  cerebrum.  2.  The  middle  lobe.  3.  The  posterior  lobe  almost  concealed  by  (4) 
the  hemisphere  of  the  cerebellum.  5.  The  pyramidal  lobe  of  the  inferior  vermiform 
process  of  the  cerebellum.  6.  The  pneumogastric  lobule.  7.  The  longitudinal  fissure. 
*i.  The  olfactory  nerves,  with  their  bulbous  expansions.  9.  The  substantia  perforata  at 
t.ie  inner  termination  of  the  fissure  of  Sylvius;  the  three  roots  of  the  olfactory  nerve  are 
seen  upon  the  substantia  perforata.  The  commencement  of  the  transverse  fissure  on 
each  side  is  concealed  by  the  inner  border  of  the  middle  lobe.  10.  The  commissure  of 
the  optic  nerves;  the  numeral  is  placed  between  the  optic  nerves  as  they  diverge  from 
Uie  commissure,  and  rests  upon  the  lamina  cinerea  of  the  corpus  callosum.  11.  The 


MEDULLA    OBLONGATA.  385 

Svlvius.  In  their  interior  they  contain  grey  matter,  which  has  a  semilunar 
shape  when  the  cms  is  divided  transversely,  and  has  been  termed  the  loan 
m"-er.  The  third  nerve  will  be  observed  to  arise  from  the  inner  side  of 
each,  and  the  fourth  nerves  wind  around  their  outer  border  from  above. 

The  Pons  Varolii*  (protuberantia  annularis,  nodus  encephali),  is  the 
broad  transverse  band  of  white  fibres  which  arches  like  abridge  across  the 
upper  part  of  the  medulla  oblongata  ;  and,  contracting  on  each  side  into  a 
thick  rounded  cord,  enters  the  substance  of  the  cerebellum  under  the  name 
of  crus  cerebelli.  There  is  a  groove  along  its  middle  which  lodges  the 
basilar  artery.  The  pons  Varolii  is  the  commissure  of  the  cerebellum,  and 
associates  the  two  lateral  lobes  in  their  common  function.  Resting  against 
the  pons,  near  its  posterior  border,  is  the  sixth  pair  of  nerves.  On  the 
anterior  border  of  the  crus  cerebelli,  at  each  side,  is  the  thick  bundle  of 
filaments  belonging  to  the  fifth  nerve,  and,  lying  against  its  posterior  border, 
the  seventh  pair  of  nerves.  The  upper  surface  of  the  pons  forms  a  part  of 
the  floor  of  the  fourth  ventricle. 

MEDULLA    OBLONGATA. 

The  medulla  oblongata  (bulbus  rhachidicus),  is  the  upper  enlarged  por- 
tion of  the  spinal  cord.  It  is  somewhat  conical  in  shape,  and  a  little  more 
than  an  inch  in  length,  extending  from  the  pons  Varolii  to  a  point  corre- 
sponding with  the  upper  border  of  the  atlas.  On  the  middle  line,  in  front 
and  behind,  the  medulla  oblongata  is  marked  by  two  vertical  fissures,  the 
fissura  longitudinalis  anterior  and  posterior,  which  divide  it  superficially 
into  two  symmetrical  lateral  cords  or  columns ;  whilst  each  lateral  column 
is  subdivided  by  minor  grooves  into  three  smaller  cords,  namely,  the  cor- 
pora pyramidalia,  corpora  olivaria,  and  corpora  restiformia. 

The  Corpora  pyramidalia  are  two  narrow  convex  cords,  tapering  slightly 
from  above  downwards,  and  situated  one  on  either  side  of  the  fissura  lon- 
gitudinalis anterior.  At  about  an  inch  below  the  pons  the  corpora  pyra- 
midalia communicate  very  freely  across  the  fissure  by  a  decussation  of  their 
fibres,  and  at  their  point  of  entrance  into  the  pons  they  are  constricted  into 
round  cords.  The  fissura  longitudinalis  is  somewhat  enlarged  by  this 
constriction,  and  the  enlarged  space  has  received  the  name  of  foramen 
caecum  of  the  medulla  oblongata. 

The  Corpora  olivaria  (named  from  some  resemblance  to  the  shape  of 
an  olive),  are  two  oblong,  oval-shaped,  convex  bodies,  of  about  the  same 
breadth  with  the  corpora  pyramidalia,  about  half  an  inch  in  length,  and 

tuber  cinereum,  from  which  the  infimdibulum  is  seen  projecting.  12.  The  corpora  al- 
bicantia.  13.  The  locus  perforatus,  bounded  on  each  side  by  the  crura  cerebri,  a»d  by 
the  third  nerve.  H.  The  pons  Varolii.  15.  The  crus  cerebelli  of  one  side.  16.  Thr» 
fifth  nerve  emerging  from  the  anterior  border  of  the  crus  cerebelli ;  the  small  nerv«?  by 
its  side  is  the  fourth.  17.  The  sixth  pair  of  nerves.  18.  The  seventh  pair  of  nerves  con- 
sisting of  the  auditory  and  facial.  19.  The  corpora  pyramidalia  of  the  medulla  oblongata; 
the  corpus  olivare  and  part  of  the  corpus  restiforme  are  seen  at  each  side.  Just  below 
the  numeral  is  the  decussation  of  the  fibres  of  the  corpora  pyramidalia.  20.  The  eighth 
pair  of  nerves.  21.  The  ninth  or  hypoglossal  nerve.  22.  The  anterior  root  of  the  first 
cervical  spinal  nerve. 

*  Constant  Varolius,  Professor  of  Anatomy  in  Bologna:  died  in  1578.  He  dissected 
the  brain  in  the  course  of  its  fibres,  beginning  from  the  medulla  oblongata  ;  a  plan  whict 
has  since  been  perfected  by  Vieussens,  and  by  Gall  and  Spurzheim.  The  work  con 
taining  his  mode  of  dissection,  "  De  Resolutione  Corporis  Humani,''  was  published  after 
his  death,  in  1591. 

33  z 


386  DIVERGING    FIBRES. 

somewhat  larger  above  than  below.  The  corpus  olivare  is  situated  imme- 
diately external  to  the  corpus  pyramidale,  from  which,  and  from  the  corpus 
restiforme,  it  is  separated  by  a  well-marked  groove.  In  this  groove  some 
longitudinal  fibres  are  seen  which  enclose  the  base  of  the  corpus  olivare, 
and  have  been  named  funiculi  siliquce,  those  which  lie  to  its  inner  side 
being  the  funiculus  internus,  and  those  to  its  outer  side  the  funiculus  ex- 
ternus.  Besides  these  there  are  other  fibres  which  cross  the  corpus  olivare 
obliquely,  these  are  the  fibres  arciformes.  When  examined  by  section 
(Fig.  175),  the  corpus  olivare  is  found  to  be  a  ganglion  deeply  embedded 
in  the  medulla  oblongata,  and  meeting  its  fellow  at  the  middle  line  behind 
the  corpus  pyramidale.  The  ganglion  of  the  corpus  olivare  (corpus  den- 
tatum,  nucleus  olivse),  like  that  of  the  cerebellum,  is  a  yellowish-grey  den- 
tated  capsule,  open  behind,  and  containing  medullary  substance  from  which 
a  fasciculus  of  fibres  proceeds  upwards  to  the  corpora  quadrigemina  and 
thalami  optici.  The  nervous  filaments  which  spring  from  the  groove 
on  the  anterior  border  of  the  corpus  olivare,  are  those  of  the  hypoglossal 
nerve ;  and  those  on  its  posterior  border  are  the  glosso-pharyngeal  and 
pneumogastric. 

The  Corpora  restiformia  (restis,  a  rope),  comprehend  the  whole  of  the 
posterior  half  of  each  lateral  column  of  the  medulla  oblongata.  They  are 
separated  from  the  corpora  olivaria  by  the  grooves  already  spoken  of; 
posteriorly  they  are  divided  from  each  other  by  the  fissura  longitudinalis 
posterior  and  by  the  fourth  ventricle,  and  superiorly  they  diverge  and  curve 
backwards  to  enter  the  cerebellum,  and  constitute  its  inferior  peduncles. 
Along  the  posterior  border  of  each  corpus  restiforme,  and  marked  off  from 
that  body  by  a  groove,  is  a  narrow  white  cord,  separated  from  its  fellow 
by  the  fissura  longitudinalis  posterior.  This  pair  of  narrow  cords  are 
termed  the  posterior  median  columns  or  fasciculi  (funiculi  graciles).  Each 
fasciculus  forms  an  enlargement  (processus  clavatus)  at  its  upper  end,  and 
is  then  lost  in  the  corresponding  corpus  restiforme.  The  processus  clavati 
are  the  lateral  boundaries  of  the  nib  of  the  calamus  scriptorius.  The  cor- 
pus restiforme  is  crossed  near  its  entrance  into  the  cerebellum,  by  the  au- 
ditory nerve,  the  choroid  plexus  of  the  fourth  ventricle,  and  the  pneurao- 
gastric  lobule. 

The  remaining  portion  of  the  medulla  oblongata  visible  from  the  exte- 
rior, are  the  two  slightly  convex  columns  which  enter  into  the  formation 
of  the  floor  of  the  fourth  ventricle.  These  columns  are  the  funiculi  teretes 
or  posterior  pyramids. 

DIVERGING  FIBRES. — The  fibres  composing  the  columns  of  the  medulla 
oblongata  have  a  special  arrangement  on  reaching  the  upper  part  of  that 
body,  those  of  the  corpora  pyramidalia  and  olivaria  enter  the  pons  Varolii, 
and  are  thence  prolonged  through  the  crura  cerebri,  thalami  optici,  and 
corpora  striata  to  the  cerebral  hemispheres ;  but  those  of  the  corpora  resti- 
formia are  reflected  backwards  into  the  cerebellum  and  form  its  inferior 
peduncles. 

From  pursuing  this  course,  and  spreading  out  as  they  advance,  these 
•fibres  have  been  termed  by  Gall  the  diverging  fibres.  While  situated 
within  the  pons,  the  fibres  of  the  corpus  pyramidale  and  olivare  separate 
and  spread  out,  and  have  grey  substance  interposed  between  them  ;  and 
they  quit  the  pons  much  increased  in  number  and  bulk,  so  as  to  form  the 
crns  cerebri.  The  fibres  of  the  crus  cerebri  again  are  separated  in  the 
Jmlamus  onticus,  and  are  intermingled  \\ith  grey  matter,  and  they  also 


FIBRES    OF   THE    BRAIN. 


387 


Fig.  173» 


quit  that  body  greatly  increased  in  number  and  bulk.  Precisely  the  same 
change  takes  place  in  the  corpus  striatum,  and  the  fibres  are  now  so  extra- 
ordinarily multiplied  as  to  be  ca- 
pable of  forming  a  large  proportion 
of  the  hemispheres. 

Observing  this  remarkable  in- 
crease in  the  white  fibres,  appa- 
rently from  the  admixture  of  grey 
substance,  Gall  and  Spurzheim 
considered  the  latter  as  the  mate- 
rial of  increase  or  formative  sub- 
stance to  the  white  fibres,  and  they 
are  borne  out  in  this  conclusion  by 
several  collateral  facts,  among  the 
most  prominent  of  which  is  the 
great  vascularity  of  the  grey  sub- 
stance ;  and  the  larger  proportion 
of  the  nutrient  fluid  circulating 
through  it  is  fully  capable  of  effect- 
ing the  increased  growth  and  nu- 
trition of  the  structures  by  which 
it  is  surrounded.  For  a  like  rea- 
son, the  bodies  in  which  this  grey 
substance  occurs,  are  called  by  the  same  physiologists  "ganglia  of 
increase,"  and  by  other  authors  simply  ganglia.  Thus  the  thalami 
optici  and  corpora  striata  are  the  ganglia  of  the  cerebrum;  or,  in  other 
words,  the  formative  ganglia  of  the  hemispheres. 

The  fibres  of  the  corpora  pyramidalia  are  not  all  of  them  destined  to  the 
course  above  described ;  several  fasciculi  curve  outwards  to  reach  the  cor- 
pora restiformia,  some  passing  in  front  and  some  behind  the  corpus  olivare 
on  each  side.  These  are  the  arciform  fibres,  and  they  are  distinguished 
by  Mr.  Solly  into  the  superficial  and  deep  cerebellar  fibres.  In  the  pons 
Varolii  the  continued  or  cerebral  fibres  (Solly)  of  the  corpus  pyramidale 
are  placed  between  the  superficial  and  deep  layers  of  transverse  fibres, 
and  escaping  from  the  pons,  constitute  the  inferior  and  inner  segment  of 
the  crus  cerebri.  From  the  crus  cerebri  they  pass  for  the  most  part  be- 
neath the  thalami  optici  into  the  corpora  striata. 

*  The  base  of  the  brain,  upon  which  several  sections  have  been  made,  showing  the 
distribution  of  the  diverging  fibres.  1.  The  medulla  oblongata.  2.  One  half  of  the  poijs 
Varolii.  3.  The  crus  cerebri  crossed  by  the  optic  nerve  (4)  and  spreading  out  into  the 
hemisphere  to  form  the  corona  radiata.  5.  The  optic  nerve  near  its  origin;  the  nerves 
about  the  crus  cerebri  and  cerebelli  are  the  same  as  in  the  preceding  figure.  6.  The 
olfactory  nerve.  7.  The  corpora  albicantia.  On  the  right  side  a  portion  of  the  brain 
has  beon  removed  to  show  the  distribution  of  the  diverging  fibres.  8.  The  fibres  of  the 
corpus  pyramidale  passing  through  the  substance  of  the  pons  Varolii.  9.  The  fibres 
passing  through  the  thalamns  opticus.  10.  The  fibres  passing  through  the  corpus 
striatum.  11.  Their  distribution  to  the  hemisphere.  12.  The  fifth  nerve:  its  two  roots 
may  be  traced,  the  one  forwards  to  the  fibres  of  the  corpus  pyramidale,  the  other  back- 
wards to  the  fasciculi  teretes.  13.  The  fibres  of  the  corpus  pyramidale  which  pass  out- 
wards with  the  corpus  restiforme  into  the  substance  of  the  cerebellum  ;  these  are  the 
arciform  fibres  of  Solly.  The  fibres  referred  to  are  those  below  the  numeral,  the  nu- 
meral itself  rests  upon  the  corpus  olivare.  14.  A  section  through  one  of  the  heini 
spheres  of  the  cerebellum,  showing  the  corpus  rhomboideum  in  the  centre  of  its  white 
substance;  the  arbor  vitae  is  also  seen.  15.  The  opposite  hemisphere  of  the  oere- 
Dellum 


388  CONVERGING    FIBRES. 

The  fibres  which  enclose  the  corpus  olivare,  under  the  name  of  fasciculi 
siliquce,  are  separated  by  that  body  into  two  bands ;  the  innermost  of  the 
two  bands,  funiculus  siliqucs  internus,  accompanies  the  fibres  of  the  corpus 
pyramidale  into  the  crus  cerebri.  The  funiculus  siliquce  externus  unites 
with  a  fasciculus  proceeding  from  the  nucleus  olivae,  and  the  combined 
column  ascending  behind  the  crus  cerebelli  divides  into  a  superior  and  an 
inferior  band.  The  inferior  band  proceeds  with  a  fasciculus  presently  to  be 
described,  the  fasciculus  innominatus,  into  the  upper  segment  of  the  crus 
cerebri.  The  superior  band  (laqueus)  ascends  by  the  side  of  the  pro- 
cessus  e  cerebello  ad  testes,  and,  crossing  the  latter  obliquely,  enters  the 
corpora  quadrigemina,  in  which  many  of  its  fibres  are  distributed,  while 
the  rest  are  continued  onwards  into  the  thalamus  opticus. 

The  corpora  restiformia  derive  their  fibres  from  the  anterior  as  well  as 
from  the  posterior  columns  of  the  medulla  oblongata;  they  diverge  as  they 
approach  the  cerebellum,  and  leaving  behind  them  the  cavity  of  the  fourth 
ventricle,  enter  the  substance  of  the  cerebellum,  under  the  form  of  two 
rounded  cords.  These  cords  envelope  the  corpora  rhomboidea,  or  gan- 
glia of  increase,  and  then  expand  on  all  sides  so  as  to  constitute  the  cere- 
bellum. 

Besides  the  fibres  here  described,  there  are,  in  the  interior  of  the  me- 
dulla oblongata,  behind  the  corpora  olivaria,  and  more  or  less  apparent 
between  these  bodies  and  the  corpora  restiformia,  two  large  bundles  of 
fibres,  the  fasciculi  innominata.  These  fasciculi  ascend  behind  the  deep 
transverse  fibres  of  the  pons  Varolii,  and  become  apparent  in  the  floor  of 
the  fourth  ventricle,  under  the  name  of  fasciculi  teretes,  or  posterior 
pyramids.  From  this  point  they  are  prolonged  upwards  beneath  the  cor- 
pora quadrigemina  into  the  crura  cerebri,  of  which  they  form  the  upper 
and  outer  segment,  and  are  thence  continued  through  the  thalami  optici 
and  corpora  striata  into  the  hemispheres.  The  locus  niger  of  the  crus 
cerebri  is  a  septum  of  grey  matter  interposed  between  these  fasciculi  and 
those  of  the  corpora  pyramidalia. 

CONVERGING  FIBRES. — In  addition  to  the  diverging  fibres  which  are 
thus  shown  to  constitute  both  the  cerebrum  and  cerebellum,  by  their 
increase  and  development,  another  set  of  fibres  are  found  to  exist,  which 
have  for  their  office  the  association  of  the  symmetrical  halves  and  distant 
parts  of  the  same  hemispheres. 

These  are  called,  from  their  direction,  converging  fibres,  and  from  their 
office,  commissures.  The  commissures  of  the  cerebrum  and  cerebellum 
are  the — 

Corpus  callosum, 

Fornix, 

Septum  lucidum, 

Anterior  commissure, 

Middle  commissure, 

Posterior  commissure, 

Peduncles  of  the  pineal  gland, 

Pons  Varolii. 

The  Corpus  callosum  is  the  commissure  of  the  hemispheres.  It  is 
therefore  of  moderate  thickness  in  the  middle,  where  its  fibres  pass 
directly  from  one  hemisphere  to  the  other ;  thicker  in  front  (genu),  where 
the  anterior  lobes  are  connected ;  and  thickest  behind  (splenium),  where 


SPINAL    CORD.  389 

the  fibres  from  the  posterior  lobes  are  assembled.  The  fibres  which  curve 
backwards  into  the  posterior  lobes  from  the  splenium  of  the  corpus  callo- 
sum  have  been  termed  forceps,  those  which  pass  directly  outwards  into 
the  middle  lobes  from  the  same  point,  tapetum,  and  those  which  curve 
forwards  and  inwards  from  the  genu  to  the  anterior  lobes,  forceps  anterior. 

The  Fornix  is  an  antero-posterior  commissure,  and  serves  to  connect  a 
number  of  parts.  Below,  it  is  associated  with  the  thalami  optici ;  on  each 
side,  by  means  of  the  corpora  fimbriata,  with  the  middle  lobes  of  the 
brain ;  and,  above,  with  the  corpus  callosum,  and  consequently  with  the 
hemispheres. 

The  Septum  lucidum  is  a  perpendicular  commissure  between  the  fornix 
and  corpus  callosum. 

The  interior  commissure  traverses  the  corpus  striatum,  and  connects 
the  anterior  and  middle  lobes  of  opposite  hemispheres. 

The  Middle  commissure  is  a  layer  of  grey  substance,  uniting  the  thalami 
optici. 

The  Posterior  commissure  is  a  white  rounded  cord,  connecting  the 
thalami  optici. 

The  Peduncles  of  the  pineal  gland  must  also  be  regarded  as  commis- 
sures, assisted  in  their  function  by  the  grey  substance  of  the  gland. 

The  Pons  Varolii  is  the  commissure  to  the  two  hemispheres  of  the  cere- 
bellum. It  consists  of  transverse  fibres,  which  are  split  into  two  layers  by 
the  passage  of  the  fasciculi  of  the  corpora  pyramidalia  and  corpora  olivaria. 
These  two  layers,  the  superior  and  inferior,  are  collected  together  on  each 
side,  in  the  formation  of  the  crura  cerebelli. 


SPINAL    CORD. 

The  dissection  of  the  spinal  cord  requires  that  the  spinal  column  should 
be  opened  through  its  entire  length  by  sawing  through  the  laminae  of  the 
vertebrae,  close  to  the  roots  of  the  transverse  processes,  and  raising  the 
arches  with  a  chisel ;  the  muscles  of  the  back  having  been  removed  as  a 
preliminary  step. 

The  Spinal  column  contains  the  spinal  cord,  or  medulla  spinalis;  the 
roots  of  the  spinal  nerves  ;  and  the  membranes  of  the  cord,  viz.  the  dura 
mater,  arachnoid,  pia  mater,  and  membrana  dentata. 

The  Dura  mater  spinalis  (theca  vertebralis)  is  a  cylindrical  sheath  of 
fibrous  membrane,  identical  in  structure  with  the  dura  mater  of  the  skull, 
And  continuous  with  that  membrane.  At  the  margin  of  the  occipital  fora- 
men it  is  closely  adherent  to  the  bone ;  by  its  anterior  surface  it  is  attached 
o  the  posterior  common  ligament,  and  below,  by  means  of  its  pointed 
extremity,  to  the  coccyx.  In  the  rest  of  its  extent  it  is  comparatively 
free,  being  connected,  by  a  very  loose  areolar  tissue  only,  to  the  walls  of 
the  spinal  canal.  In  this  areolar  tissue  there  exists  a  quantity  of  reddish, 
oily,  adipose  substance,  somewhat  analogous  to  the  marrow  of  long  bones 
On  either  side  and  below,  the  dura  mater  forms  a  sheath  for  each  of  the 
spinal  nerves,  to  which  it  is  closely  adherent.  Upon  its  inner  surface  it  is 
smooth,  being  lined  by  the  arachnoid ;  and  on  its  sides  may  be  seen 
double  openings  for  the  two  roots  of  each  of  the  spinal  nerves. 

The  Arachnoid,  is  a  continuation  of  the  serous  membrane  of  the  brain. 
It  encloses  the  cord  very  loosely,  being   connected  to  it  only  by  long 
33* 


390  SPINAL    CORD. 

slender  filaments*  of  areolar  tissue,  and  by  a  longitudinal  lamella  which  Is 
attached  to  the  posterior  aspect  of  the  cord.  The  areolar  tissue  is  most 
abundant  in  the  cervical  region,  and  diminishes  in  quantity  from  above 
downwards ;  and  the  longitudinal  lamella  is  complete  only  in  the  dorsal 
region.  The  arachnoid  passes  off  from  the  cord  on  either  side  with  the 
spinal  nerves,  to  which  it  forms  a  sheath ;  and  is  then  reflected  on  the 
dura  mater,  to  constitute  its  serous  surface.  A  connexion  exists  in  several 
situations  between  the  arachnoid  of  the  cord  and  that  of  the  dura  mater. 
The  space  between  the  arachnoid  and  the  spinal  cord  is  identical  with 
that  already  described  as  existing  between  the  same  parts  in  the  brain, 
the  sub-arachnoidean  space.  It  is  occupied  by  a  serous  fluid,  sufficient  in 
quantity  to  expand  the  arachnoid,  and  fill  completely  the  cavity  of  the 
theca  vertebralis.  The  sub-arachnoidean  fluid  keeps  up  a  constant  and 
gentle  pressure  on  the  entire  surface  of  the  brain  and  spinal  cord,  and 
yields  with  the  greatest  facility  to  the  various  movements  of  the  cord, 
giving  to  those  delicate  structures  the  advantage  of  the  principles  so  use- 
fully occupied  by  Dr.  Arnott  in  the  hydrostatic  bed. 

The  Pia  mater  is  the  immediate  investment  of  the  cord  ;  and,  like  the 
other  membranes,  is  continuous  with  that  of  the  brain.  It  is  not,  however, 
like  the  pia  mater  cerebri,  a  vascular  membrane ;  but  is  dense  and  fibrous 
in  structure,  and  contains  but  few  vessels.  It  invests  the  cord  closely, 
and  sends  a  duplicature  into  the  fissura  longitudinalis  anterior,  and  an- 
other, extremely  delicate,  into  the  fissura  longitudinalis  posterior.  It  forms 
a  sheath  for  each  of  the  filaments  of  the  nerves,  and  for  the  nerves  them- 
selves ;  and,  inferiorly,  at  the  conical  termination  of  the  cord,  is  prolonged 
downwards  as  a  slender  ligament  (filum  terninale),  which  descends 
through  the  centre  of  the  cauda  equina,  and  is  attached  to  the  dura  mater 
lining  the  canal  of  the  coccyx.  This  attachment  is  a  rudiment  of  the 
original  extension  of  the  spinal  cord  into  the  canal  of  the  sacrum  and 
coccyx.  The  pia  mater  hasf  distributed  to  it,  a  number  of  nervous  plexuses 
derived  from  the  sympathetic. 

The  Membrana  dentata  (ligamentum  dentatum)  is  a  thin  process  of  pia 
mater  sent  off  from  each  side  of  the  cord  throughout  its  entire  length,  and 
separating  the  anterior  from  the  posterior  roots  of  the  spinal  nerves.  The 
number  of  serrations  on  each  side  is  about  twenty,  the  first  being  situated 
on  a  level  with  the  occipital  foramen,  and  having  the  vertebral  artery  and 
hypoglossal  nerve  passing  in  front  and  the  spinal  accessory  nerve  behind 
it,  and  the  last  opposite  the  first  or  second  lumbar  vertebra.  Below  this 
point,  the  membrana  dentata  is  lost  in  the  filum  terminale  of  the  pia  mater. 
The  use  of  this  membrane  is  to  maintain  the  position  of  the  spinal  cord  in 
the  midst  of  the  fluid  by  which  it  is  surrounded. 

The  Spinal  cord  of  the  adult  extends  from  the  pons  Varolii  to  opposite 
the  first  or  second  lumbar  vertebra,  where  it  terminates  in  a  rounded 
point ;  in  the  child,  at  birth,  it  reaches  to  the  middle  of  the  third  lumbar 
vertebra,  and  in  the  embry*  is  prolonged  as  far  as  the  coccyx.  It  pre- 
sents a  difference  of  diameter  in  different  parts  of  its  extent,  and  exhibits 
three  enlargements.  The  uppermost  of  these  is  the  medulla  oblongata ; 
the  next  corresponds  with  the  origin  of  the  nerves  destined  to  the  upper 
extremities ;  and  the  lower  enlargement  is  situated  near  its  termination, 

According  to  Mr.  Rainey,  these  filaments  are  nervous  fasciculi,  having  their  origin 
in  the  irachnoid,  and  passing  to  the  arteries  of  the  cord.     See  page  371. 


SPINAL    CORD. 


301 


Fig.  174.» 


and  corresponds  with  the  attachment  of  the  nerves  which  are  intended  for 
the  supply  of  the  lower  limb. 

In  form,  the  spinal  cord  is  a  flattened  cylinder,  and  presents  on  its  an- 
terior surface  a  fissure,  which  extends  into  the  cord  to  the  depth  of  one- 
third  of  its  diameter.  This  is  the  fissura  longitudinalis  anterior.  If  the 
sides  of  the  fissure  be  gently  separated,  they  will  be  seen  to  be  connected 
at  the  bottom  by  a  layer  of  medullary  substance,  the  anterior  commissure. 

On  the  posterior  surface  another  fissure  exists,  which  is  so  narrow  be- 
tween the  second  cervical  and  second  lumbar  nerve,  as  to  be  hardly  per- 
ceptible. This  is  the  fissura  longitudinalis  posterior.  It  extends  more 
deeply  into  the  cord  than  the  anterior  fissure,  and  terminates  in  the  grey 
substance  of  the  interior.  These  two  fissures  divide  the  medulla  spinalis 
into  two  lateral  cords,  which  are  connected  to  each  other  by  the  white 
commissure  which  forms  the  bottom  of  the  anterior  longitudinal  fissure, 
and  by  a  commissure  of  grey  matter  situated  behind  the  former.  On  either 
side  of  the  fissura  longitudinalis  posterior  is  a  slight  line  which  bounds  on 
each  side  the  posterior  median  columns.  These  columns  are  most  appa- 
rent at  the  upper  part  of  the  cord,  near  the  fourth  ventricle,  where  they 
are  separated  by  the  point  of  the  calamus  scriptorius,  and  where  they  form 
the  bulbous  enlargement  at  each  side,  called  processes  clavatus. 

Two  other  lines  are  observed 
on  the  medulla,  the  anterior 
and  posterior  lateral  sulci,  cor- 
responding  with  the  attach- 
ment  of  the  anterior  and  poste- 
rior  roots  of  the  spinal  nerves. 
The  anterior  lateral  sulcus  is  a 
mere  trace,  marked  only  by 
the  attachment  of  the  filaments 
of  the  anterior  roots.  The  pos- 
terior lateral  sulcus  is  more 
evident,  and  is  a  narrow  grey- 
ish line  derived  from  the  grey 
substance  of  the  interior. 

Although  these  fissures  and  sulci  indicate  a  division  of  the  spinal  co:  i 
into  three  pairs  of  columns,  namely,  anterior,  lateral,  and  posterior,  the 
posterior  median  columns  being  regarded  as  a  part  of  the  posterior  co- 
lumns, it  is  customary  to  consider  each  half  of  the  spinal  cord  as  consist- 
ing of  two  columns  only,  the  antero-lateral  and  the  posterior.  The  ante.ro- 
lateral  columns  are  the  columns  of  motion,  and  comprehend  all  that  part 
of  the  cord  situated  between  the  fissura  longitudinalis  anterior  and  the 
posterior  lateral  sulcus,  the  grey  line  of  origin  of  the  posterior  roots  of  the 
spinal  nerves.  The  posterior  columns  are  the  columns  of  sensation. 

If  a  transverse  section  of  the  spinal  cord  be  made,  its  internal  structure 
may  be  seen  and  examined.  It  will  then  appear  to  be  composed  of  two 
hollow  cylinders  of  white  matter,  placed  side  by  side,  and  connected  by  a 
narrow  white  commissure.  Each  cylinder  is  filled  with  grey  substance, 

*  Sections  of  the  spinal  marrow  in  different  portions  of  its  length.  1.  Opposite  tho 
llth  dorsal  vertebra.  2.  Opposite  the  10th  dorsal.  3.  Opposite  the  8th  dorsal.  4.  Op- 
posite the  5th  dorsal.  5.  Opposite  the  7th  cervical.  6.  Opposite  the  4th  cervical.  7. 
Opposite  the  3d  cervical.  8.  Section  of  medulla  oblongata  tl;-ough  the  corpora  oli 
varia. 


392  CRANIAL    NERVES. 

Fig.  115*  which  is  connected  by  a  commissure  of  the 

A  B          same  matter.     The  form  of  the  grey  sub- 

stance, as  observed  in  the  section,  is  that  of 
two  irregularly  curved  lines  joined  by  a 
transverse  band.  The  extremities  of  the 
curved  lines  correspond  to  the  sulci  of  origin 
of  the  anterior  and  posterior  roots  of  the 
nerves.  The  anterior  extremities,  larger  than 
the  posterior,  do  not  quite  reach  this  surface  ;  but  the  posterior  appear  upon 
the  surface,  and  form  a  narrow  grey  line,  the  sulcus  lateralis  posterior. 

The  white  substance  of  the  spinal  cord  is  composed  of  parallel  fibres, 
which  are  collected  into  longitudinal  laminae  and  extend  throughout  the 
entire  length  of  the  cord.  These  lamina?  are  various  in  breadth,  and  are 
arranged  in  a  radiated  manner ;  one  border  being  thick  and  corresponding 
with  the  surface  of  the  cord,  while  the  other  is  thin  and  lies  in  contact 
with  the  grey  substance  of  the  interior.  According  to  Rolando  the  white 
substance  constitutes  a  simple  nervous  membrane,  which  is  folded  into 
longitudinal  plaits,  having  the  radiated  disposition  above  described.  The 
anterior  commissure,  according  to  his  description,  is  merely  the  continua- 
tion of  this  nervous  membrane  from  one  lateral  cord  across  the  middle 
line  to  the  other.  Moreover,  Rolando  considers  that  a  thin  lamina  of  pia 
mater  is  received  between  each  of  the  folds  from  the  exterior,  while  a  layer 
of  the  grey  substance  is  prolonged  between  them  from  within.  Cruveil- 
hier  is  of  opinion  that  each  lamella  is  completely  independent  of  its  neigh- 
bours, and  he  believes  this  statement  to  be  confirmed  by  pathology,  which 
shows  that  a  single  lamella  may  be  injured  or  atrophied,  and  at  the  same 
time  be  surrounded  by  others  perfectly  sound. 

CRANIAL    NERVES. 

There  are  nine  pairs  of  cranial  nerves.  Taken  in  their  order  from 
before,  backwards,  they  are  as  follows : 

1st.  Olfactory. 

2d.  Optic. 

3d.  Motores  oculorurn. 

4th.  Pathetici  (trochleares). 

5th.  Trifacial  (trigemini). 

6th.  Abducentes. 

•y,,      (  Facial  (portio  dura, 

\  Auditory  (portio  mollis). 

*  Sections  of  the  spinal  cord.  After  Arnold.  A.  A  section  made  across  the  lower 
part  of  the  corpora  olivaria.  1,  1.  Corpora  pyramidalia.  2.  Fissura  longitudinalis  an- 
verior.  3.  The  corpus  olivare ;  in  the  section  of  which  the  zig-zag  outline  of  the  corpus 
•lentatum  is  seen.  4.  The  corpus  restiforme.  5.  The  grey  substance  of  the  corpus 
lesnforrne.  6.  The  corpora  pyramidalia  posteriora.  7.  The  floor  of  the  fourth  ven 
triole. 

B.  A  section  made  between  the  third  and  fourth  cervical  nerves.  1.  The  fissura 
<v>ng:tudinalis  anterior.  2.  An  indentation  corresponding  in  situation  with  the  fissura 
icngitudinalis  posterior,  which  latter  is  not  distinguishable  at  this  part  of  the  spinal 
cord.  3,  3.  The  nntero-lateral  columns  of  the  spinal  cord.  4,  4.  The  posterior  columns. 
5.  The^  anterior  cornu  of  grey  matter.  6.  Its  posterior  cornu,  terminating  at  7,  the  sulcus 
lateralis  posterior.  8.  The  isthmus  connecting  the  grey  matter  of  the  two  sides  of  the 
:ord. 


OLFACTORY    NERVE. 


393 


(  Glosso-pharyngeal, 
8th.   <  Pneumogastric  (vagus,  par  vagum). 

(  Spinal  accessory. 
9th.  Hypoglossal  (lingual). 

Functionally  or  physiologically  the  cranial  nerves  admit  of  division  into 
three  groups,  namely,  nerves  of  special  sense,  nerves  of  motion,  and  com- 
pound nerves,  that  is,  nerves  which  contain  fibres  both  of  sensation  and 
motion.  The  nerves  belonging  to  these  groups  are  the  following : 

f  1st.  Olfactory. 

Special  sense <  2d.  Optic. 

[  7th.  Auditory. 
3d.  Motores  oculorum. 
4th.  Pathetici. 

Motion -I  6th.  Abducentes. 

7th.  Facial. 

9th.  Hypoglossal. 

5th.  Trifacial. 


Compound 


8th.  Glosso-pharyngeal. 
Pneumogastric. 
Spinal  accessory. 


The  fourth,  facial,  and  eighth  nerves  were  considered  by  Sir  Charles 
Bell  to  form  a  system  apart  from  the  rest,  and  to  be  allied  in  the  functions 
of  expression  and  respiration.  In  consonance  with  this  view  he  termed 
them  respiratory  nerves,  and  he  gave  to  that  part  of  the  medulla  oblongata 
from  which  they  arise  the  name  of  respiratory  tract. 


Fig.  176.* 


FIRST  PAIR.  OLFACTORY. 
— The  olfactory  nerve  arises 
by  three  roots  ;  an  inner  root 
from  the  substantia  perforata, 
a  middle  root  from  a  papil- 
la of  grey  matter  (caruncu- 
la  mammillaris),  embedded 
in  the  anterior  lobe,  and  an 
external  root,  which  may  be 
traced  as  a  white  streak  along 
the  fissure  of  Sylvius  into 
the  corpus  striatum,  where 
it  is  continuous  with  some  of 
the  fibres  of  the  anterior  com- 
missure. The  nervous  cord 

formed  by  the  union  of  these  three  roots  is  soft  in  texture,  prismoid  in  shape, 
and  embedded  in  a  sulcus  between  two  convolutions  on  the  under  surface  of 
each  anterior  lobe  of  the  brain,  lying  between  the  pia  mater  and  the  arach- 
noid. As  it  passes  forwards  it  increases  in  breadth  and  swells  at  its  extremity, 

*  A  view  of  the  1st  pair  or  olfactory,  with  the  nasal  branches  of  the  5th.  1.  Frontal 
sinus.  2.  Sphenoidal  sinus.  3.  Hard  palate.  4.  Bulb  of  the  olfactory  nerve.  5. 
Branches  of  the  olfactory  on  the  superior  and  middle  turbinated  bones.  6.  Spheno-pala- 
tine  nerves  from  the  2d  of  the  5th.  7.  Internal  nasal  nerve  from  the  1st  of  the  5tb..  8. 
Branches  of  7,  to  Schrieiderian  membrane.  9.  Ganglion  of  Cloquet  in  the  foramen  ind 
tivitm.  10.  Anastomosis  on  the  inferior  turbinated  bone  of  the  branches  of  the  5th  pan 


394 


OPTIC    NERVE. 


into  an  obiong  mass  of  grey  and  white  substance,  the  bulbus  olfactorius, 
which  rests  upon  the  cribriform  lamella  of  the  ethmoid  bone.     From  the 

under  surface  of  the  bulbous  olfacto- 
s'  ries  are  given  off  the  nerves  which 

pass  through  the  cribriform  foramina 
and  supply  the  mucous  membrane 
of  the  nares;  they  are  arranged  into 
two  groups,  an  inner  group,  reddish 
in  colour  and  soft,  which  spread  out 
upon  the  septum  narium,  and  au 
outer  group,  whiter  and  more  firm, 
which  descend  through  the  bony  ca- 
nals in  the  outer  wall  of  the  nares, 
and  are  distributed  upon  the  superior 
and  middle  turbinated  bones. 

SECOND  PAIR.  OPTIC. — The  optic 
nerve,  a  nerve  of  large  size,  arises 
from  the  corpora  geniculata  on  the 
posterior  and  inferior  aspect  of  the 
thalamus  opticus  and  from  the  nates. 
Proceeding  from  this  origin  it  winds 
around  the  crus  cerebri  as  a  flattened 
band,  under  the  name  of  tractus  opticus,  and  joins  with  its  fe]low  in  front 
of  the  tuber  cinereum  to  form  the  antic  commissure  (chiasma).  The  tractus 

opticus  is  united  with  the  crus 
cerebri  and  tuber  cinereum,  and 
is  covered  in  by  the  pia  mater ; 
the  commissure  is  also  connected 
with  the  tuber  cinereum,  from 
which  it  receives  fibres,  and  the 
nerve  beyond  the  commissure 
diverges  from  its  fellow,  becomes 
rounded  in  form,  and  is  enclosed 
in  a  sheath  derived  from  the 
arachnoid.  In  passing  through 
the  optic  foramen  the  optic  nerve 
receives  a  sheath  from  the  dura 
mater,  which  splits  at  this  point 
into  two  layers ;  one,  which  be- 
^  x  ^  comes  the  periosteum  of  the 

*  A  view  of  the  2d  pair  or  optic,  and  the  origins  of  seven  other  pairs.  1,  1.  Globe 
of  the  eye,  the  one  on  the  left  hand  is  perfect,  but  that  on  the  right  has  the  sclerotic  and 
choroid  removed  to  show  the  retina.  2.  The  chiasm  of  the  optic  nerves.  3.  The  cor- 
pora albicantia.  4.  The  infundibulum.  5.  The  pons  Varolii.  6.  The  medulla  ol> 
longata.  The  figure  is  on  the,  right  corpus  pyramidale.  7.  The  3d  pair,  motores  oculi. 
8.  4th  pair,  pathetici.  9.  5th  pair,  trigemini.  10th.  6th  pair,  abducentes.  11.  7th  pair, 
auditory  and  facial.  12th.  8th  pair,  pneumogastric,  spinal  accessory,  and  glosso-pha- 
ryngeal.  13.  9th  pair,  hypoglossal. 

t  The  isthmus  encephali,  showing  the  thalamus  opticus,  corpora  quadrigemina,  pons 
Varolii,  and  medulla  oblongata,  as  viewed  from  the  side.  1.  The  thalamus  opticus. 

2.  The  posterior  prominence  of  this  body,  tuberculum   superius    posterius  or  pulvirmr. 

3.  The  corpus  geniculatum   externum.     4.  The  corpus  geniculatum   internum.     5.  The 
commencement  of  the  tractus  opticus.     6.  The   pineal   gland.     7.  The  nates.     8.  The 


Fig.  17  8.t 


MOTORES  OCULORUM PATHETICI.  395 

orbit ;  the  other,  the  one  in  question,  which  forms  a  sheath  for  the  nerve, 
and  is  lost  in  the  sclerotic  coat  of  the  eyeball.  After  a  short  course  within 
the  orbit  the  optic  nerve  pierces  the  sclerotic  and  choroid  coats  and  ex- 
pands into  the  nervous  membrane  of  the  eyeball,  the  retina.  Near  the 
globe,  the  nerve  is  pierced  by  a  small  artery,  the  arteria  centralis  retinae, 
which  runs  through  the  central  axis  of  the  nerve  and  reaches  the  internal 
surface  of  the  retina,  to  which  it  distributes  branches. 

The  commissure  rests  upon  the  processus  olivaris  of  the  sphenoid  bone  ; 
it  is  bounded  by  the  lamina  cinerea  of  the  corpus  callosum  in  front,  by  the 
substantia  perforata  on  each  side,  and  by  the  tuber  cinereum  behind. 
Within  the  commissure  the  innermost  fibres  of  the  optic  nerves  cross  each 
other  to  pass  to  opposite  eyes,  while  the  outer  fibres  continue  their  course 
uninterruptedly  to  the  eye  of  the  corresponding  side.  The  neurilemma 
of  the  commissure,  as  well  as  that  of  the  nerves,  is  formed  by  the  pia 
mater. 

THIRD  PAIR.  MOTORES  OCULORUM. — The  motor  oculi,  a  nerve  of  mo- 
derate size,  arises  from  the  inner  side  of  the  crus  cerebri,  close  to  the  pons 
Varolii,  and  passes  forward  between  the  posterior  cerebral  and  superior 
cerebellar  artery.  It  pierces  the  dura  mater  immediately  in  front  of  the 
posterior  clinoid  process  ;  descends  obliquely  along  the  external  wall  of 
the  cavernous  sinus  ;  and  divides  into  twro  branches  which  enter  the  orbit 
between  the  two  heads  of  the  external  rectus  muscle.  The  superior 
branch  ascends,  and  supplies  the  superior  rectus  and  levator  palpebra?. 
The  inferior  sends  a  branch  beneath  the  optic  nerve  to  the  internal  rectus, 
another  to  the  inferior  rectus,  and  a  long  branch  to  the  inferior  oblique 
muscle.  From  the  latter  a  short  thick  branch  is  given  off  to  the  ciliary 
ganglion,  forming  its  inferior  root. 

The  fibres  of  origin  of  this  nerve  may  be  traced  into  the  grey  substance 
of  the  crus  cerebri,*  into  the  motor  tract, f  and  as  far  as  the  superior  fibres 
of  the  crus  cerebri.  |  In  the  cavernous  sinus  it  receives  one  or  two  fila- 
ments from  the  cavernous  plexus,  and  one  from  the  ophthalmic  nerve. 

FOURTH  PAIR.  PATHETIC:  (trochlearis). — The  fourth  is  the  smallest 
cerebral  nerve  ;  it  arises  from  the  valve  of  Vieussens  close  to  the  the  testis, 
and  winding  around  the  crus  cerebri  to  the  extremity  of  the  petrous  portion 
of  the  temporal  bone,  pierces  the  dura  mater  near  the  oval  opening  for  the 

testis  of  one  side.  9.  The  brachium  anterius  of  the  corpora  quadrigemina.  a.  The 
brachium  posterius.  b.  The  origin  of  the  fourth  nerve,  which  may  be  seen  descending 
over  the  crus  cerebri.  c.  The  processus  e  cerebello  ad  testem,  or  superior  peduncle  of 
the  cerebellum,  d.  The  band  of  fibres  termed  laqneus,  the  superior  division  of  the  fas- 
ciculus olivaris  crossing  the  superior  peduncle  of  the  cerebellum  to  enter  the  corpora 
quadrigemina.  Through  the  small  triangular  space  in  front  of  this  band,  crossed  by 
the  fourth  nerve,  some  of  the  fibres  of  the  superior  peduncle  of  the  cerebellum  may  be 
seen.  e.  The  superior  portion  of  the  crus  cerebri,  termed  tegmentum.  f.  Its  inferior 
portion,  g.  The  third  nerve,  h.  The  pons  Varolii.  t.  The  crus  cerebelli,  or  middle 
peduncle  of  the  cerebellum,  k.  The  inferior  peduncle  derived  from  the  corpus  resti- 
forme.  The  mass  lying  in  the  angular  interval  upon  these  is  the  superior  peduncle. 
I.  The  fifth  nerve  issuing  from  between  the  transverse  fasciculi  of  the  pons  Varolii.  m. 
The  sixth  nerve,  n.  The  seventh  nerve ;  the  inferior  and  smaller  cord  is  the  facial 
nerve,  the  superior  and  larger  the  auditory,  o.  The  corpus  olivare  crossed  inferiorly 
by  the  superficial  arciform  fibres,  p.  The  corpus  pyramidale.  q.  The  median  posto 
rior  fasciculi  of  the  medulla  oblongata.  r.  The  corpus  restiforme.  «.  The  spinal  cord. 
t.  The  fourth  ventricle. 

*  Mayo.  •}-  Solly.  $  Grainger. 


39G 


TRIFACIAL. 


Fig.  179.»  fifth  nerve,  and  passes  along  the  outer 

•wall  of  the  cavernous  sinus  to  the 
sphenoidal  fissure.  In  its  course 
through  the  sinus  it  is  situated  at  first 
below  the  motor  oculi,  but  afterwards 
ascends  and  becomes  the  highest  of 
the  nerves  which  enter  the  orbit 
through  the  sphenoidal  fissure.  Upon 
entering  the  orbit  the  nerve  crosses 
the  levator  palpebra  muscle  near  its 
origin,  and  is  distributed  upon  the 
orbital  surface  of  the  superior  oblique 
or  trochlearis  muscle ;  hence  its  syno- 
nyn  trochlearis. 

Branches. — While  in  the  cavernous 
sinus  the  fourth  nerve  gives  off  a  re- 
current branch,  some  filaments  of  communication  to  the  ophthalmic  nerve, 
and  a  branch  to  assist  in  forming  the  lachrymal  nerve ;  the  recurrent  branch, 
which  consists  of  sympathetic  filaments  derived  from  the  carotid  plexus, 
passes  backwards  between  the  layers  of  the  tentorium,  and  divides  into 
two  or  three  filaments,  which  are  distributed  to  the  lining  membrane  of 
the  lateral  sinus.  This  nerve  is  sometimes  a  branch  of  the  ophthalmic, 
and  occasionally  proceeds  directly  from  the  carotid  plexus. 

FIFTH  PAIR.  TRIFACIAL  (trigeminus). — The  fifth  nerve,  the  great  sen- 
sitive nerve  of  the  head  and  face,  and  the  largest  cranial  nerve,  is  analogous 
to  the  spinal  nerves  in  its  origin  by  two  roots,  from  the  anterior  and  pos- 
terior columns  of  the  spinal  cord,  and  in  the  existence  of  a  ganglion  on 
the  posterior  columns  of  the  spinal  cord,  and  in  the  existence  of  a  ganglion 
on  the  posterior  root.  It  arisesf  from  a  tract  of  yellowish-white  matter 
situated  in  front  of  the  floor  of  the  fourth  ventricle  and  the  origin  of  the 
auditory  nerve,  and  behind  the  crus  cerebelli.  This  tract  divides  inferiorly 
into  two  fasciculi  which  may  be  traced  downwards  into  the  spinal  cord, 
one  being  continuous  with  the  fibres  of  the  anterior  column,  the  other  with 
the  posterior  column.  Proceeding  from  this  origin  the  two  roots  of  the  nerve 
pass  forward,  and  issue  from  the  brain  upon  the  anterior  part  of  the  crus 
cerebelli,  where  they  are  separated  by  a  slight  interval.  The  anterior  is 
much  smaller  than  the  posterior,  and  the  two  together  constitute  the  fifth 
nerve,  which  in  this  situation  consists  of  seventy  to  a  hundred  filaments  held 
together  by  pia  mater.  The  nerve  then  passes  through  an  oval  opening  in 
the  border  of  the  tentorium,  near  the  extremity  of  the  petrous  bone,  and 
spreads  out  into  a  large  semilunar  ganglion,  the  Casserian.  If  the  ganglion 
be  turned  over,  it  will  be  seen  that  the  anterior  root  lies  against  its  under 

*  A  view  of  the  3d,  4th,  and  6th  pairs  of  nerves.  1.  Ball  of  the  eye,  the  rectns  exter- 
nus  muscle  being  cut  and  hanging  clown  from  its  origin.  2.  The  superior  maxilla.  3. 
The  third  pair  or  rriotor  oculi  distributed  to  all  the  muscles  of  the  eye  except  the  supe- 
rior oblique  and  external  rectus.  4.  The  4th  pair  or  patheticus  going  to  the  superior 
oblique  muscle.  5.  One  of  the  branches  of  the  5th.  6.  The  6th  pair  cr  motor  externus 
distributed  to  the  external  rectus  muscle.  7.  Spheno-palatine  ganglion  and  branches. 
8.  Ciliary  nerves  from  the  lenticular  ganglion,  the  short  root  of  which  is  seen  to  connect 
it  with  the  3d  pair. 

f  I  have  adopted  the  origin  of  this  nerve,  given  by  Dr.  Alcock,  of  Dublin,  as  the  result 
of  lii-s  directions,  in  the  Cyclopaedia  of  Anatomy  and  Physiology.  Mr.  Mayo  also  traces 
th«  an.enor  root  of  the  nerve  to  a  similar  origin. 


OPHTHALMIC    NERVE. 


397 


surface  without  having  any  connexion  with  it,  and  may  be  followed  onwards 
to  the  inferior  maxillary  nerve.  The  Casserian  ganglion  divides  into  three 
branches,  the  ophthalmic,  superior  maxillary,  and  inferior  maxillary. 

The  OPHTHALMIC  NERVE  is  a  short  trunk,  being  not  more  than  three 
quarters  of  an  inch  in  length ;  it  arises  from  the  upper  angle  of  the  Casse- 
rian ganglion,  beneath  the  dura  mater,  and  passes  forwards  through  the 
outer  wall  of  the  cavernous  sinus,  lying  externally  to  the  other  nerves ;  it 
divides  into  three  branches.  Previously  to  its  division  it  receives  several 
filaments  from  the  carotid  plexus,  and  gives  off  a  small  recurrent  nerve, 
that  passes  backwards  with  the  recurrent  branch  of  the  fourth  nerve  between 
the  two  layers  of  the  tentorium  to  the  lining  membrane  of  the  lateral  sinus. 

The  Branches  of  the  ophthalmic  nerve  are,  the — 


Frontal, 


Lachrymal, 


Nasal. 


Fig.  180.* 


The  Frontal  nerve  mounts  above  the  levator  palpebree,  and  runs  for- 
ward, resting  upon  that  muscle,  to  the  supra-orbital  foramen,  through 
which  it  escapes  upon  the  forehead,  with  the  supra-orbital  artery.  It  sup- 
plies the  conjunctiva  and  upper  eyelid,  and  the  integument  of  the  cranium 
as  far  as  the  vertex. 

The  frontal  nerve  gives  off  but  one  small  branch,  the  supra-trochlear, 
which  passes  inwards  above  the  pulley  of  the  superior  oblique  muscle,  and 
ascends  along  the  middle  line  of  the  forehead,  distributing  filaments  to  the 
integument,  to  the  inner  angle  of  the  eye  and  root  of  the  nose,  and  to  the 
conjunctiva. 

The  Lachrymal  nerve,  the  smallest  of  the  three  branches  of  the  ophthal- 
mic, receives  a  filament  from  the  fourth  nerve  in  the  cavernous  sinus,  and 
passes  outwards  along  the  upper  border  of  the  external  rectus  muscle,  and 
in  company  with  the  lachrymal  artery,  to  the  lachrymal  gland,  where  it 
divides  into  two  branches.  The  superior 
branch  passes  along  the  upper  surface 
of  the  gland  and  through  a  foramen  in 
the  malar  bone,  and  is  distributed  upon 
the  temple  and  cheek,  communicating 
with  the  subcutaneus  malse  and  facial 
nerves.  The  inferior  branch  supplies 
the  lower  surface  of  the  gland  and  con- 
junctiva, and  terminates  in  the  integu- 
ment of  the  upper  lid  communicating 
with  the  facial  nerve. 

The  Nasal  nerve  (naso-ciliaris)  passes 
forwards  between  the  two  heads  of  the 
external  rectus  muscle,  crosses  the  optic 
nerve  in  company  with  the  ophthalmic 
artery,  and  enters  the  anterior  ethmoidal 
foramen  immediately  above  the  internal 
rectus.  It  then  traverses  the  upper  part 
of  the  ethmoid  bone  to  the  cribriform 
plate,  and  passes  downwards  through 
the  slit-like  opening  by  the  side  of  the 

«  A  view  of  the  distribution  of  the  trifacial  or  5th  pair. — 1.  Orbit.  2.  Antrum  of  H^h 
more.  3.  Tongue.  4.  Lower  maxilla.  5.  Root  of  5th  pair  forming  the  ganglion  of 
Casser.  6.  1st  branch,  Ophthalmic.  7.  2d  branch,  Superior  maxillary.  8.  3d  hr-xnch 

34 


398  SUPERIOR  MAXILLARY  NERVE. 

crista  galli  into  the  nose,  where  it  divides  into  two  branches  —  an  internal, 
branch  supplying  the  mucous  membrane,  near  the  anterior  openings  of  the 
nares  ;  and  an  external  branch  which  passes  between  the  fibro,-cartilages, 
and  is  distributed  to  the  integument  at  the  extremity  of  the  nose. 

The  Branches  of  the  nasal  nerve  within  the  orbit  are,  the  ganglionic, 
ciliary,  and  infra-trochlear  ;  in  the  nose  it  gives  off  one  or  two  filaments 
to  the  anterior  ethmoidal  cells  and  frontal  sinus.  The  ganglionic  branch 
passes  obliquely  forwards  to  the  superior  angle  of  the  ciliary  ganglion, 
forming  its  superior  long  root.  The  ciliary  branches  are  two  or  three  fila- 
ments which  are  given  off  by  the  nasal  as  it  crosses  the  optic  nerve.  They 
pierce  the  posterior  part  of  the  sclerotic,  and  pass  between  that  tunic  and 
the  choroid  to  be  distributed  to  the  iris.  The  infra-trochlear  is  given  off 
just  as  the  nerve  is  about  to  enter  the  anterior  ethmoidal  foramen.  It 
passes  along  the  superior  border  of  the  internal  rectus  to  the  inner  angle 
of  the  eye,  where  it  communicates  with  the  supra-trochlear  nerve,  and 
supplies  the  lachrymal  sac,  caruncula  lachrymalis,  conjunctiva,  and  inner 
angle  of  the  orbit. 

The  SUPERIOR  MAXILLARY  NERVE,  larger  than  the  preceding,  proceeds 
from  the  middle  of  the  Casserian  ganglion  ;  it  passes  forwards  through  the 
foramen  rotundum,  crosses  the  spheno-maxillary  fossa,  and  enters  the 
canal  in  the  floor  of  the  orbit,  along  which  it  runs  to  the  infra-orbital  fora- 
men. Emerging  on  the  face,  beneath  the  levator  labii  superioris  muscle, 
it  divides  into  a  number  of  branches,  which  are  distributed  to  the  lower 
eyelid  and  conjunctiva,  and  to  the  muscles  and  integument  of  the  upper 
lip,  nose,  and  cheek,  forming  a  plexus  with  the  facial  nerve. 

The  Branches  of  the  superior  maxillary  nerve  are  divisible  into  three 
groups:  —  1.  Those  which  are  given  off  in  the  spheno-maxillary  fossa. 
2.  Those  in  the  infra-orbital  canal;  and  3.  Those  on  the  face.  They 
may  be  thus  arranged  : 

(  Orbital, 

Spheno-maxillary  fossa,  <  Two  from  Meckel's  ganglion, 
Posterior  dental. 


Infra-orbital  canal,  f  ?dle  df^\ 

(  Anterior  dental. 

On  the  face,  Muscular, 

(  Cutaneous. 


The  Orbital  branch  (n.  subcutaneus  malae)  enters  the  orbit  through  the 
spheno-maxillary  fissure,  and  divides  into  two  branches,  temporal  and 
malar;  the  temporal  branch  ascends  along  the  outer  wall  of  the  orbit,  and, 
after  receiving  a  branch  from  the  lachrymal  nerve,  passes  through  a  canal 

Inferior  maxillary.  9.  Frontal  branch,  dividing  into  external  and  internal  fmntal  at  14. 
10.  Lachrymal  branch,  dividing  before  entering  the  lachrymal  gland.  11.  Na-nl  branch. 
Tust  under  the  figure  is  the  long  root  of  the  lenticular  or  ciliary  ganglion,  arid  a  few  of 
the  ciliary  nerves.  12.  Internal  nasal,  disappearing  through  the  anterior  ethmoidal  fora- 
men. 13.  External  nasal.  14.  External  and  internal  frontal.  15.  Infra-orbitary  nerve. 
if).  Posterior  dental  branches.  17.  Middle  dental  branch.  18.  Anterior  dental  nerve. 
.  Terminating  branches  of  infra-orbital,  called  labial  and  palpebral.  20.  Subcutaneus 
malse  or  orbitar  branch.  21.  Pterygoid  or  recurrent,  from  Meckel's  ganglion.  22.  Five 
anterior  branches  of  3d  of  5th,  being  nerves  of  motion,  and  called  masseter,  temporal, 
pterygoid  and  buccal.  23.  Lingual  branch  joined  at  an  acute  angle  by  the  chorda  tym- 
oam.  24.  Inferior  dental  nerve  terminating  in,  25.  Mental  branches.  26.  Superficial 
nerve.  27.  Auricular  branches.  28.  Mylo-hyoid  branch. 


INFERIOR    MAXILLARY    NERVE.  399 

in  the  malar  bone  and  enters  the  temporal  fossa ;  it  then  pierces  the  tem- 
poral muscle  and  fascia  and  is  distributed  to  the  integument  of  the  temple 
and  side  of  the  forehead,  communicating  with  the  facial  and  anterior 
auricular  nerve.  In  the  temporal  fossa  it  communicates  with  the  deep 
temporal  nerves.  The  malar,  or  inferior  branch,  takes  its  course  along 
the  lower  angle  of  the  outer  wall  of  the  orbit,  and  emerges  upon  the  cheek 
through  an  opening  in  the  malar  bone,  passing  between  the  fibres  of  the 
oibicularis  palpebrarum  muscle.  It  communicates  with  branches  of  the 
infra-orbital  and  facial  nerves. 

The  Two  branches  from  Meckel's  ganglion  ascend  from  that  body  to 
join  the  nerve,  'as  it  crosses  the  spheno-maxillary  fossa. 

The  Posterior  dental  branches  pass  through  small  foramina,  in  the 
posterior  surface  of  the  superior  maxillary  bone,  and  running  forwards  in 
the  base  of  the  alveolus,  supply  the  posterior  teeth  and  gums. 

The  Middle  and  anterior  dental  branches  descend  to  the  corresponding 
teeth  and  gums ;  the  former  beneath  the  lining  membrane  of  the  antrum, 
the  latter  through  distinct  canals  in  the  walls  of  the  bone.  Previously  to 
their  distribution,  the  dental  nerves  form  a  plexus  (superior  maxillary 
plexus)  in  the  outer  wall  of  the  superior  maxillary  bone  immediately  above 
the  alveolus.  From  this  plexus  the  filaments  are  given  off  \vhich  supply 
the  pulps  of  the  teeth,  the  gums,  the  mucous  membrane  of  the  floor  of  the 
nares,  and  the  palate.  Some  gangliform  masses  have  been  described  in 
connexion  with  this  plexus,  one  being  placed  over  the  canine,  and  another 
over  the  second  molar  tooth. 

The  Muscular  and  cutaneous  branches  are  the  terminating  filaments  of 
the  nerve ;  they  supply  the  muscles,  integument,  and  mucous  membrane 
of  the  cheek,  nose,  and  lip,  and  form  an  intricate  plexus  with  branches 
of  the  facial  nerve. 

The  INFERIOR  MAXILLARY  NERVE  proceeds  from  the  inferior  angle  of 
the  Casserian  ganglion  ;  it  is  the  largest  of  the  three  divisions  of  the  fifth 
nerve,  and  is  augmented  in  size  by  the  anterior  or  motor  root,  which 
passes  behind  the  ganglion,  and  unites  with  the  inferior  maxillary  as  it 
escapes  through  the  foramen  ovale.  Emerging  at  the  foramen  ovale  the 
nerve  divides  into  twro  trunks,  external  and  internal,  which  are  separated 
from  each  other  by  the  external  pterygoid  muscle. 

The  External  trunk,  into  which  may  be  traced  nearly  the  whole  of  the 
motor  root,  immediately  divides  into  five  branches  which  are  distributed 
to  the  muscles  of  the  temporo-maxillary  region  ;  they  are — 

The  Masseteric,  which  crosses  the  sigmoid  notch  with  the  masseteric 
artery  to  the  masseter  muscle.  It  sends  a  small  branch  to  the  temporal 
muscle,  and  a  filament  to  the  temporo-maxillary  articulation. 

Temporal ;  two  branches  passing  between  the  upper  border  of  the  ex- 
ternal pterygoid  muscle  and  the  temporal  bone  to  the  temporal  muscle. 
Two  or  three  filaments  from  these  nerves  pierce  the  temporal  fascia,  and 
communicate  with  the  lachrymal,  subcutaneous  malae,  auricular  and  facial 
nerve. 

Buccal;  a  large  branch  which  pierces  the  fibres  of  the  external  ptery- 
goid, to  reach  the  buccinator  muscle.  This  nerve  sends  filaments  to  the 
temporal  ind  external  pterygoid  muscle,  to  the  mucous  membrane  and 
integument  of  the  cheek,  and  communicates  with  the  facial  nerve. 


400  INFERIOR    DENTAL    NERVE. 

Internal  pterygoid ;  a  long  and  slender  branch,  which  passes  inwards 
to  the  internal  pterygoid  muscle,  and  gives  filaments  in  its  course  to  the 
tensor  palati  and  tensor  tympani.  This  nerve  is  remarkable  from  its  con- 
nexion with  the  otic  ganglion,  to  which  it  is  attached. 

The  Internal  trunk  divides  into  three  branches — 

Gustatory, 
Inferior  dental, 
Anterior  auricular. 

The  GUSTATORY  NERVE  descends  between  the  two  pterygoid  muscles 
to  the  side  of  the  tongue,  where  it  becomes  flattened,  and  divides  into 
numerous  filaments,  which,  are  distributed  to  the  papillae  and  mucous 
membrane. 

Relations. — It  lies  at  first  between  the  external  pterygoid  muscle  and 
the  pharynx,  next  between  the  two  pterygoid  muscles,  then  between  the 
internal  pterygoid  and  ramus  of  the  jaw,  and  between  the  stylo-glossus 
muscle  and  the  submaxillary  gland  ;  lastly,  it  runs  along  the  side  of  the 
tongue,  resting  upon  the  hyo-glossus  muscle,  and  covered  in  by  the  mylo- 
hyoideus  and  mucous  membrane. 

The  gustatory  nerve,  while  between  the  two  pterygoid  muscles,  receives 
a  branch  from  the  inferior  dental ;  lower  down  it  is  joined  at  an  acute 
angle  by  the  chorda  tympani  which  passes  downwards  in  the  sheath  of  the 
gustatory  to  the  submaxillary  gland,  where  it  unites  with  the  submaxillary 
ganglion.  On  the  hyo-glossus  muscle  some  branches  of  communication 
are  sent  to  the  hypoglossal,  and  in  the  course  of  the  nerve  several  small 
branches  to  the  mucous  membrane  of  the  fauces,  to  the  tonsils,  submaxil- 
lary gland,  Wharton's  duct,  and  sublingual  gland. 

The  INFERIOR  DENTAL  NERVE  passes  downwards  with  the  inferior  den- 
tal artery,  at  first  between  the  two  pterygoid  muscles,  and  then  between 
the  internal  lateral  ligament  and  the  ramus  of  the  lower  jaw,  to  the  dental 
foramen.  It  then  runs  along  the  canal  in  the  inferior  maxillary  bone, 
distributing  branches  (inferior  maxillary  plexus)  to  the  teeth  and  gums, 
and  divides  into  two  terminal  branches,  incisive  and  mental.  The  incisive 
branch  passes  forwards,  to  supply  the  incisive  teeth :  the  mental  branch 
escapes  through  the  mental  foramen,  to  be  distributed  to  the  muscles  and 
integument  of  the  chin  and  lower  lip,  and  to  the  mucous  membrane  of  the 
latter,  communicating  with  the  facial  nerve. 

The  inferior  dental  nerve  gives  off  but  one  branch,  the  mylo-hyoidean, 
which  leaves  the  nerve  just  as  it  is  about  to  enter  the  dental  foramen. 
This  branch  pierces  the  insertion  of  the  internal  lateral  ligament,  and  de 
scends  along  a  groove  in  the  bone  to  the  inferior  surface  of  the  mylo- 
hyoid  muscle,  to  which,  and  to  the  anterior  belly  of  the  digastricus,  it  is 
distributed. 

The  ANTERIOR  AURICULAR  NERVE  originates  by  two  roots,  between 
which  the  arteria  meningea  media  takes  its  course,  and  passes  directly 
backwards  behind  the  articulation  of  the  lower  jaw,  against  which  it  rests. 
In  this  situation  it  divides  into  two  branches,  which  reunite,  and  form  a 
kind  of  plexus.  From  the  plexus  two  branches  are  given  off — ascending 
and  descending.  The  ascending  or  temporal  branch  sends  one  or  twu 
considerable  branches  of  communication  to  the  facial  nerve,  and  then 
ascend0  in  front  of  the  ear  to  the  temporal  region,  upon  which  it  is  distri 


FACIAL    NERVE.  401 

buted  in  company  with  the  branches  of  the  temporal  artery.  In  its  course 
it  sends  filaments  to  the  temporo-maxillary  articulation,  to  the  pinna  and 
meatus  of  the  ear,  and  to  the  integument  in  the  temporal  region.  It  com- 
municates on  the  temple  with  branches  of  the  facial,  supra-orbital,  lachry- 
mal, and  subcutaneus  malae  nerve.  The  descending  branch  enters  the 
parotid  gland,  to  which  it  sends  numerous  branches ;  it  communicates 
with  the  inferior  dental  and  auricularis  magnus  nerve,  and  supplies  the 
external  ear,  the  meatus  auditorius,  and  the  temporo-maxiilary  articulation, 
and  sends  one  or  two  filaments  into  the  tympanum. 

SIXTH  PAIR.  ABDUCENTES. — The  abducens  nerve,  about  half  the  size 
of  the  motor  oculi,  arises  by  several  filaments  from  the  upper  constricted 
part  of  the  corpus  pyramidale  close  to  the  pons  Varolii.  Proceeding  for- 
wards from  this  origin  it  lies  parallel  with  the  basilar  artery,  and,  piercing 
the  dura  mater  upon  the  clivus  Blumenbachii  of  the  sphenoid  bone,  ascends 
beneath  that  membrane  to  the  cavernous  sinus.  It  then  runs  forwards 
along  the  inner  wall  of  the  sinus  below  the  other  nerves,  and,  resting 
against  the  internal  carotid  artery,  passes  between  the  two  heads  of  the 
external  rectus,  and  is  distributed  to  that  muscle.  As  it  enters  the  orbit, 
it  lies  upon  the  ophthalmic  vein,  from  which  it  is  separated  by  a  lamina 
of  dura  mater.  In  the  cavernous  sinus  it  is  joined  by  several  filaments 
from  the  carotid  plexus,  by  one  from  Meckel's  ganglion,  and  one  from  the 
ophthalmic  nerve.  Mr.  Mayo  traced  the  origin  of  this  nerve  between  the 
fasciculi  of  the  corpora  pyramidalia  to  the  posterior  part  of  the  medulla 
oblongata;  and  Mr.  Grainger  pointed  out  its  connexion  with  the  grey 
substance  of  the  spinal  cord. 

SEVENTH  PAIR. — The  seventh  pair  consists  of  two  nerves  which  lie  side 
by  side  on  the  posterior  border  of 
the  crus  cerebelli.  The  smaller  and 
most  internal  of  these,  and,  at  the 
same  time,  the  most  dense  in  tex- 
ture, is  the  facial  nerve  or  portio 
dura.  The  external  nerve,  which 
is  soft  and  pulpy,  and  often  grooved 
by  contact  with  the  preceding,  is 
the  auditory  nerve  or  portio  mollis 
of  the  seventh  pair.  Soemmering 
makes  the  auditory  nerve  the  eighth 
pair;  but,  retaining  the  classifica- 
tion of  Willis,  wre  regard  it  as 
a  part  of  the  seventh  with  the 
facial. 

FACIAL  NERVE  (portio  dura).  —  The  facial  nerve  arises  from  the  jpper 
part  of  the  groove  between  the  corpus  olivare  and  corpus  restiforme,  close 
to  the  pons  Varolii,  from  which  point  its  fibres  may  be  traced  deeply  into 
the  corpus  restiforme.  The  nerve  then  passes  forwards,  resting  upon  the 

»  A  view  of  the  origin  and  distribution  of  the  portio  mollis  of  the  7th  pair  or  auditory 
nerve.  1.  The  medulla  oblongata.  2.  The  pons  Varolii.  3  and  4.  The  crura  cerebelli 
of  the  right  side.  5.  8th  pair.  6.  9th  pair.  7.  The  auditory  nerve  distributed  to  tins 
cochlea  and  labyrinth.  8.  The  6th  pair.  9.  The  portio  dura  of  the  7th  pair.  10.  Th« 
4»b  pair.  11.  The  3d  pair. 

34*  2  A 


402  FACIAL    NERVE. 

crus  cerebelli,  and  comes  i-  to  relation  with  the  auditory  nerve,  with  whick 
it  enters  the  meatus  auditorius  internus,  lying  at  first  to  the  inner  side  of, 
and  then  upon  that  nerve.  At  the  bottom  of  the  meatus  it  enters  the  canal 
expressly  intended  for  it,  the  aqueductus  Fallopii,  and  directs  its  course 
forwards  towards  the  hiatus  Fallopii,  where  it  forms  a  gangliform  swelling 
(intumescentia  gangliformis),  and  receives  the  petrosal  branch  of  the  Vidian 
nerve.  It  then  curves  backwards  towards  the  tympanum,  and  descends 
along  the  inner  wall  of  that  cavity  to  the  stylo-mastoid  foramen.  Emerg- 
ing at  the  stylo-mastoid  foramen  it  passes  forwards  within  the  parotid 
gland,  crossing  the  external  jugular  vein  and  external  carotid  artery,  and 
at  the  ramus  of  the  lower  jaw  divides  into  two  trunks,  temporo-facial  and 
cervico-fadal.  These  trunks  at  once  split  into  numerous  branches,  which, 
after  forming  a  number  of  looped  communications  (pes  anserinus)  with 
each  other  over  the  masseter  muscle,  spread  out  upon  the  side  of  the  face, 
from  the  temple  to  the  neck,  to  be  distributed  to  the  muscles  of  this  exten- 
sive region.  The  communications  which  the  facial  nerve  maintains  in  its 
course  are  the  following  :  in  the  meatus  auditorius,  it  sends  one  or  two 
filaments  to  the  auditory  nerve  ;  the  intumescentia  gangliformis  receives 
the  nervus  petrosus  superficialis  major  and  minor,  and  sends  a  twig  back 
to  the  auditory  nerve  ;  behind  the  tympanum  the  nerve  receives  one  or 
two  twigs  from  the  auricular  branch  of  the  pneumogastric  ;  at  its  exit  from 
the  stylo-mastoid  foramen  it  receives  a  twig  from  the  glosso-pharyngeal, 
and  in  the  parotid  gland  one  or  two  large  branches  from  the  anterior 
auricular  nerve.  Besides  these,  the  facial  nerve  has  numerous  peripheral 
communications,  with  the  branches  of  the  fifth  nerve  on  the  face,  and  of 
the  cervical  nerves  in  the  parotid  gland  and  neck.  The  numerous  com- 
munications of  the  facial  nerve  obtained  for  it  the  designation  of  nervus 
sympatheticus  minor. 

The  Branches  of  the  facial  nerve  are  — 

Within    the    aqueductus   (  Tympanic, 

\  Chorda  tympani. 


an  •          .    ,7     C  Posterior  auricular. 

Jifler   emerging    at    the  i  „.  ,    ,      .  , 
4  7         4  -j  f  \  Stylo-hyena. 

stylo-mastoid  foramen,  j  -p.-'     ,  < 
•*•  '  (  Digastric. 


S  Temporo-facial, 
\  Cervico-facial. 


The  Tympanic  branch  is  a  small  filament  distributed  to  the  stapedius 
muscle. 

The  Chorda  tympani  quits  the  facial  just  before  that  nerve  emerges 
from  the  stylo-mastoid  foramen,  and  ascends  by  a  distinct  canal  to  the 
upper  part  of  the  posterior  wall  of  the  tympanum,  where  it  enters  that 
cavity  through  an  opening  situated  between  the  base  of  the  pyramid  and 
the  attachment  of  the  membrana  tympani,  and  becomes  invested  by  mu 
eous  membrane.  It  then  crosses  the  tympanum  between  the  handle  of 
the  malleus  and  long  process  of  the  incus  to  the  anterior  inferior  angle  of 
the  cavity,  and  escapes  through  a  distinct  opening  in  the  fissura  Glaseri, 
and  joins  the  gustatory  nerve  at  an  acute  angle  between  the  two  pterygoid 
muscles.  Enclosed  in  the  sheath  of  the  gustatory  nerve,  it  descends  to 
the  submaxillary  gland,  where  it  unites  with  the  submaxillary  ganglion 

The  Posterior  auricular  nerve  ascends  behind  the  ear,  between  the 


AUDITORY    NERVE. 


403 


182» 


meatus  and  mastoid  process,  and  divides  into  an  anterior  and  a  poste- 
rior branch.  The  anterior  branch  receives  a  filament  of  communication 
from  the  auricular  branch  of 
the  pneumogastric  nerve,  and 
distributes  filaments  to  the  re- 
trahens  and  attollens  aurem 
muscles  and  to  the  pinna. 
The  posterior  branch  commu- 
nicates with  the  auricularis 
magnus  and  occipitalis  minor, 
and  is  distributed  to  the  poste- 
rior belly  of  the  occipito-fron- 
talis. 

The  Stylo-liyoid  branch  is 
distributed  to  the  stylo-hyoid 
muscle. 

The  Digastric  branch  sup- 
plies the  posterior  belly  of  the 
digastricus  muscle,  and  com- 
municates with  the  glosso- 
pharyngeal  and  pneumogastric 
nerve. 

The  Temporo-fadal  gives  off  a  number  of  branches,  which  are  distri- 
buted over  the  temple  and  upper  half  of  the  face,  supplying  the  muscles 
of  this  region,  and  communicating  with  the  branches  of  the  auricular,  the 
subcutaneus  mala;,  and  the  supra-orbital  nerve.  The  inferior  branches, 
which  accompany  Stenon's  duct,  and  form  a  plexus  with  the  terminal 
branches  of  the  infra-orbital  nerve. 

The  Cervico-fadal  divides  into  a  number  of  branches  that  are  distri- 
buted to  muscles  on  the  lower  half  of  the  face  and  upper  part  of  the  neck. 
The  cervical  branches  form  a  plexus  with  the  superficialis  colli  nerve  over 
the  submaxillary  gland,  and  are  distributed  to  the  platysma  myoides. 

AUDITORY  NERVE  (portio  mollis). — The  auditory  nerve  takes  its  origin 
in  the  lineae  transversae  (striae  medullares)  of  the  anterior  wall  or  floor  of 
the  fourth  ventricle,  and  winds  around  the  corpus  restiforme,  from  which 
it  receives  fibres,  to  the  posterior  border  of  the  cms  cerebelli.  It  then 
passes  forwards  upon  the  crus  cerebelli  in  company  with  the  facial  nerve, 
which  lies  in  a  groove  on  its  superior  surface,  and  enters  the  meatus 

*  The  distribution  of  the  facial  nerve  and  the  branches  of  the  cervical  plexus.  1.  The 
facial  nerve,  escaping  from  the  stylo-mastoid  foramen,  and  crossing  the  ramus  of  the 
lower  jaw ;  the  parotid  gland  has  been  removed  »n  order  to  see  the  nerve  more  dis- 
tinctly. 2.  The  posterior  auricular  branch ;  the  digastric  and  stylo-masto'd  filaments 
are  seen  near  the  origin  of  this  branch.  3.  Temporal  branches,  communicating  with 
(4)  the  branches  of  the  frontal  nerve.  5.  Facial  branches,  communicating  with  (6)  the 
infra-orbital  nerve.  7.  Facial  branches,  communicating  with  (8)  the  mental  nerve. 
&.  Cervico-facial  branches,  communicating  with  (10)  the  superficialis  colli  nerve,  and 
forming  a  plexus  (11)  over  the  submaxillary  gland.  The  distribution  of  the  branches 
of  the  facial  in  a  radiated  direction  over  the  side  of  the  face  and  theit  looped  commu- 
nications constitute  the  pes  anserinus.  12.  The  auricularis  magnus  nerve,  one  of  th«» 
ascending  branches  of  the  cervical  plexus.  13.  The  occipitalis  minor,  ascending  along 
the  posterior  border  of  the  sterno-mastoid  muscle.  14.  The  superficial  and  deep  de- 
scending branches  of  the  cervical  plexus.  15.  The  spinal  accessory  nerve,  giving  ofF  a 
branch  to  the  external  surface  of  the  trapezius  muscle.  16.  The  occipitalis  major  nervs, 
the  oosterior  branch  of  the  second  cervical  nerve. 


404  GLOSSO-PHARYNGEAL   NERVE. 

auditorius  internus,  and  at  the  bottom  of  the  meatus  it  divides  into  tw» 
branches,  cochlear  and  vestibular.  The  auditory  nerve  is  soft  and  pulpy 
in  texture,  and  receives  in  the  meatus  auditorius  several  filaments  from  the 
facial  nerve. 

EIGHTH  PAIR.  —  The  eighth  pair  consists  of  three  nerves,  glosso- 
pharyngeal,  pneumogastric,  and  spinal  accessory;  these  are  the  ninth 
tenth,  and  eleventh  pairs  of  Soemmering. 

GLOSSO-PHARYNGEAL  NERVE.  —  The  glosso-pharyngeal  nerve  arises  by 
five  or  six  filaments  from  the  groove  between  the  corpus  olivare  and  resti 
forme,  and  escapes  from  the  skull  at  the  innermost  extremity  of  the  jugular 
foramen  through  a  distinct  opening  in  the  dura  mater,  lying  anteriorly  to 
the  sheath  of  the  pneumogastric  and  spinal  accessory  nerves,  and  internally 
to  the  jugular  vein.  It  then  passes  forwards  between  the  jugular  vein  and 
internal  carotid  artery,  to  the  stylo-pharyngeus  muscle,  and  descends 
along  the  inferior  border  of  that  muscle  to  the  hyo-glossus,  beneath  which 
it  curves  to  be  distributed  to  the  mucous  membrane  of  the  base  of  the 
tongue  and  fauces,  to  the  mucous  glands  of  the  mouth,  and  to  the  tonsils. 
While  situated  in  the  jugular  fossa,  the  nerve  presents  two  gangliform 
swellings;  one  superior  (ganglion  jugulare  of  Miiller)  of  small  size,  and 
involving  only  the  posterior  fibres  of  the  nerve  ;  the  other  inferior,  nearly 
half  an  inch  below  the  preceding,  of  larger  size  and  occupying  the  whole 
diameter  of  the  nerve,  the  ganglion  of  Andersch*  (ganglion  petrosum). 

The  fibres  of  origin  of  this  nerve  may  be  traced  through  the  fasciculi 
of  the  corpus  restiforme  to  the  grey  substance  in  the  floor  of  the  fourth 
ventricle. 

The  Branches  of  the  glosso-pharyngeal  nerve  are — 

Communicating  branches  with  the  Facial, 

Pneumogastric, 
Spinal  accessory, 
Sympathetic. 

Tympanic, 

Muscular, 

Pharyngeal, 

Lingual, 

Tonsillitic. 

The  Branches  of  communication  proceed  from  the  ganglion  and  from 
the  upper  part  of  the  trunk  of  the  nerve,  and  are  common  to  the  facial, 
eighth  pair,  and  sympathetic ;  they  form  a  complicated  plexus  at  the  base 
of  the  skull. 

The  Tympanic  branch  (Jacobson's  nerve)  proceeds  from  the  o-anglion 
of  Andersch,  or  from  the  trunk  of  the  nerve  immediately  above  the  gan- 
glion :  it  enters  a  small  bony  canal  in  the  jugular  fossa  (page  G8)  and 
divides  into  six  branches,  which  are  distributed  upon  the  inner  wall  of  the 
tympanum,  and  establish  a  plexiform  communication  (tympanic  plexus) 
with  the  sympathetic  and  fifth  pair  of  nerves.  The  branches  of  distribu- 
tion supply  the  fenestra  rotunda,  fenestra  ovalis,  and  Eustachian  tube : 
those  of  communication  join  the  carotid  plexus,  the  petrosal  branch  of  the 
Vidian  nerve,  and  the  otic  ganglion. 

*  Charles  Samuel  Andersch.  "  Tractatus  Anatomico-Physiologicus  de  JVcrvis  Cor 
f>oris  Humani  Aliquibus.  1797." 


PNEUMOGASTRIC    1S7ERVE.  405 

The  Muscular  branch  divides  into  filaments,  which  are  distributed  to 
the  stylo-pharyngeus  and  to  the  posterior  belly  of  the  digastricus  and 
stylo-hyoideus  muscle. 

The  Pharyngeal  branches  are  two  or  three  filaments  which  are  distri- 
buted to  the  pharynx  and  unite  with  the  pharyngeal  branches  of  the  pneu- 
mogastric  and  sympathetic  nerve  to  form  the  pharyngeal  plexus. 

The  Lingual  branches  enter  the  substance  of  the  tongue  beneath  the 
hyo-glossus  and  styio-glossus  muscle,  and  are  distributed  to  the  mucous 
membrane  of  the  side  and  base  of  the  tongue,  and  to  the  epiglottis  and 
fauces. 

The  Tonsillitic  branches  proceed  from  the  glosso-pharyngeal  nerve  near 
its  termination ;  they  form  a  plexus  (circulus  tonsillaris)  around  the  base 
of  the  tonsil,  from  which  numerous  filaments  are  given  off  to  the  mucous 
membrane  of  the  fauces  and  soft  palate,  communicating  with  the  posterior 
palatine  branches  of  Meckel's  ganglion. 

PNEUMOGASTRIC  NERVE  (vagus). — The  pneumogastric  nerve  arises  by 
ten  or  fifteen  filaments  from  the  groove  between  the  corpus  olivare  and 
corpus  restiforme,  immediately  below  the  glosso-pharyngeal,  and  passes 
out  of  the  skull  through  the  inner  extremity  of  the  jugular  foramen  in  a 
distinct  canal  of  the  dura  mater.  While  situated  in  this  canal  it  presents 
a  small  rounded  ganglion  (ganglion  jugulare) ;  and  having  escaped  from 
the  skull,  a  gangliform  swelling  (plexus  gangliformis),  nearly  an  inch  in 
length,  and  surrounded  by  an  irregular  plexus  of  white  nerves,  which 
communicate  with  each  other,  with  the  other  divisions  of  the  eighth  pair, 
and  with  the  trunk  of  the  pneumogastric  below  the  ganglion.  The  plexus 
gangliformis  (ganglion  of  the  superior  laryngeal  branch,  of  Sir  Astley 
Cooper,)  is  situated,  at  first,  behind  the  internal  carotid  artery,  and  then 
between  that  vessel  and  the  internal  jugular  vein.  The  pneumogastric 
nerve  then  descends  the  neck  within  the  sheath  of  the  carotid  vessels, 
lying  behind  and  between  the  artery  and  vein,  to  the  root  of  the  neck. 
Here  the  course  of  the  nerve  at  opposite  sides  becomes  different. 

On  the  right  side  it  passes  between  the  subclavian  artery  and  vein  to 
the  posterior  mediastinum,  then  behind  the  root  of  the  lung  to  the  eso- 
phagus, which  it  accompanies  to  the  stomach,  lying  on  its  posterior 
aspect. 

On  the  left  it  enters  the  chest  parallel  with  the  left  subclavian  artery, 
crosses  the  arch  of  the  aorta,  and  descends  behind  the  root  of  the  lung, 
and  along  the  anterior  surface  of  the  oesophagus,  to  the  stomach. 

The  fibres  of  origin  of  the  pneumogastric  nerve,  like  those  of  the  glosso- 
haryngeal,  may  be  traced  through  the  fasciculi  of  the  corpus  restiforme 
nto  the  grey  substance  of  the  floor  of  the  fourth  ventricle. 

The  Branches  of  the  pneumogastric  nerve  are  the  following : — 

Communicating  branches  with  the  Facial, 

Glosso-pharyngeal, 
Spinal  accessory, 
Hypo-glossal, 
Sympathetic. 

Auricular, 

Pharyngeal, 

Superior  laryngeal, 


40C 


SUPERIOR  LARYNGEAL  NERVE. 


Fig.  183.» 


Cardiac, 

Inferior  or  recurrent  laryngeal, 

Pulmonary  anterior, 

Pulmonary  posterior, 

CEsophageal, 

Gastric. 

The  Branches  of  communication  form  part  of  the  complicated  plexus  at 
the  base  of  the  skull.  The  branches  to  the  ganglion  of  Andersch  are  given 
off  by  the  superior  ganglion  in  the  jugular  fossa. 

The  Auricular  nerve  is  given  off  from  the 
lower  part  of  the  jugular  ganglion,  or  from  the 
trunk  of  the  nerve  immediately  below,  and  re- 
ceives immediately  after  its  origin  a  small  branch 
of  communication  from  the  glosso-pharyngeal. 
It  then  passes  outwards  behind  the  jugular  vein, 
and  on  the  outer  side  of  that  vessel  enters  a  small 
canal  (page  68)  in  the  petrous  portion  of  the 
temporal  bone  near  the  stylo-mastoid  foramen. 
Guided  by  this  canal  it  reaches  the  descending 
part  of  the  aqueductus  Fallopii  and  joins  the  fa- 
cial nerve.  In  the  aqueductus  Fallopii  the  auri- 
cular nerve  gives  off  two  small  filaments,  one  of 
which  communicates  with  the  posterior  auricular 
branch  of  the  facial,  while  the  other  is  distri- 
buted to  the  pinna. 

The  Pharyngeal  nerve  arises  from  the  pneu- 
mogastric,  immediately  above  the  gangliform 
plexus,  and  descends  behind  the  internal  carotid 
artery  to  the  upper  border  of  the  middle  constric- 
tor, upon  which  it  forms  the  pharyngeal  plexus 
assisted  by  branches  from  the  glosso-pharyngeal, 
superior  laryngeal,  and  sympathetic.  The  pha- 
ryngeal plexus  is  distributed  to  the  muscles  and 
mucous  membrane  of  the  pharynx. 

The  Superior  laryngeal  nerve  arises  from  the 
gangliform  plexus  of  the  pneumogastric,  of  which 
it  appears  to  be  almost  a  continuation ;  hence 
this  plexus  was  named  by  Sir  Astley  Cooper  the 
" ganglion  of  the  superior  laryngeal  branch." 
The  nerve  descends  behind  the  internal  carotid 
artery  to  the  opening  in  the  thyro-hyoidean  mem 
brane,  through  which  it  passes  with  the  superioi 
laryngeal  artery,  and  is  distributed  to  the  mucous 
membrane  of  the  larynx  and  arytenoideus  muscle. 
On  the  latter,  and  behind  the  cricoid  cartilage, 

•  Origin  and  distribution  of  the  eighth  pair  of  nerves.  1,  3,  4.  The  medulla  oblongata. 
1  Is  the  corpus  pyramidale  of  one  side.  3.  The  corpus  olivare.  4.  The  corpus  resti- 
forme.  2.  The  pons  Varolii.  5.  The  facial  nerve.  6.  The  origin  of  the  glosso-pharyn- 
geal nerve.  7.  The  ganglion  of  Andersch.  8.  The  trunk  of  the  nerve.  9.  The  spinal 
accessory  nerve  10.  The  ganglion  of  the  pneumogastric  nerve.  11.  Its  plexiform  gau- 


INFERIOR    LARYNGEAL    NERVE.  407 

it  communicates  with  the  recurrent  laryngeal  nerve.  Behind  the  internal 
carotid  it  gives  off  the  external  laryngeal  branch,  which  sends  a  twig  to  the 
pharyngeal  plexus,  and  then  descends  to  supply  the  inferior  constrictor 
and  crico-thyroid  muscles  and  thyroid  gland.  This  branch  communicates 
inferiorly  with  the  recurrent  laryngeal  and  sympathetic  nerve. 

Mr.  Hilton  of  Guy's  Hospital,  concludes  from  his  dissections*  that  the 
superior  laryngeal  nerve  is  the  nerve  of  sensation  to  the  larynx,  being  dis- 
tributed solely  (with  the  exception  of  its  external  laryngeal  branch  and  a 
twig  to  the  arytenoideus)  to  the  mucous  membrane.  If  this  fact  be  taken 
in  connexion  with  the  observations  of  Sir  Astley  Cooper,  and  the  dissec- 
tions of  the  origin  of  the  nerve  by  Mr.  Edward  Cock,  we  shall  have  ample 
evidence,  both  in  the  ganglionic  origin  of  the  nerve  and  in  its  distribution, 
of  its  sensitive  function.  The  recurrent,  or  inferior  laryngeal  nerve,  is  the 
proper  motor  nerve  of  the  larynx,  and  is  distributed  to  its  muscles. 

The  Cardiac  branches,  two  or  three  in  number,  arise  from  the  pneumo- 
gastric  in  the  lower  part  of  the  neck,  and  cross  the  lower  part  of  the  com- 
mon carotid,  to  communicate  with  the  cardiac  branches  of  the  sympathetic, 
and  with  the  great  cardiac  plexus. 

The  Recurrent  laryngeal,  or  inferior  laryngeal  nerve,  curves  around  the 
subclavian  artery  on  the  right,  and  the  arch  of  the  aorta  on  the  left  side. 
It  ascends  in  the  groove  between  the  trachea  and  oesophagus,  and  piercing 
the  lower  fibres  of  the  inferior  constrictor  muscle  enters  the  larynx  close 
to  the  articulation  of  the  inferior  cornu  of  the  thyroid  with  the  cricoid  car- 
tilage. It  is  distributed  to  all  the  muscles  of  the  larynx  with  the  excep- 
tion of  the  crico-thyroid,  and  communicates  on  the  arytenoideus  muscle 
with  the  superior  laryngeal  nerve.  As  it  curves  around  the  subclavian 
artery  and  aorta  it  gives  branches  to  the  heart  and  root  of  the  lungs ;  and 
as  it  ascends  the  neck  it  distributes  filaments  to  the  oesophagus  and  tra- 
chea, and  communicates  with  the  external  laryngeal  nerve  and  sympa- 
thetic. 

The  interior  pulmonary  branches  are  distributed  upon  the  anterior  as- 
pect of  the  root  of  the  lungs,  forming,  with  branches  from  the  great  car- 
diac plexus,  the  anterior  pulmonary  plexus. 

The  Posterior  pulmonary  branches,  more  numerous  than  the  anterior, 
are  distributed  upon  the  posterior  aspect  of  the  root  of  the  lungs,  and  are 
joined  by  branches  from  the  great  cardiac  plexus,  forming  the  posterior 
pulmonary  plexus. 

Upon  the  oesophagus  the  two  nerves  divide  into  numerous  branches, 
which  communicate  with  each  other  and  constitute  the  cesophageal  plexus 
which  completely  surrounds  the  cylinder  of  the  oesophagus,  and  accompa- 
nies it  to  the  cardiac  orifice  of  the  stomach. 

The  Gastric  branches  are  the  terminal  filaments  of  the  two  pneumogas- 
tric  nerves ;  they  are  spread  out  upon  the  anterior  and  posterior  surfaces 
of  the  stomach,  and  are  likewise  distributed  to  the  omentum,  spleen,  pan- 
creas, liver,  and  gall-bladder,  and  communicate,  particularly  the  right 
nerve,  with  the  solar  plexus. 

glion.  12.  Its  trunk.  13.  Its  pharyngeal  branch  forming  the  pharyngeal  plexus  (14), 
assisted  by  a  branch  from  the  glosso-pharyngeal  (8),  and  one  from  the  superior  laryn 
geal  nerve  (15).  16.  Cardiac  branches.  17.  Recurrent  laryngeal  branch.  18.  Anterior 
pulmonary  branches.  19.  PC sterior  pulmonary  branches.  20.  CEsophageal  plexus.  21. 
Gastric  branches.  22.  Origin  of  the  spinal  accessory  nerve.  23.  Its  branches  distri 
buted  to  the  sterno-mastoid  muscle.  24.  Its  branches  to  the  trapezius  muscle, 
*  Guy's  Hospital  Reports,  vol.  ii. 


408 


HYPOGLOSSAL    NERVE. 


Fig.  184» 


SPINAL  ACCESSORY  NERVE. — The  spinal  accessory  nerve   arises  by 

several  filaments  from  the  side  of  the 
spinal  cord  as  low  down  as  the  fourth 
or  fifth  cervical  nerve,  and  ascends 
behind  the  ligamentum  denticulatum, 
and  between  the  anterior  and  poste- 
rior roots  of  the  spinal  nerves,  to  the 
foramen  lacerum  posterius.  It  com- 
municates in  its  course  with  the  pos- 
terior root  of  the  first  cervical  nerve, 
and  entering  the  foramen  lacerum 
becomes  applied  against  the  poste- 
rior aspect  of  the  ganglion  jugulare 
of  the  pneumogastric,  being  con- 
tained in  the  same  sheath  of  dura 
mater.  In  the  jugular  fossa  it  di- 
vides into  two  branches  ;  the  smaller 
joins  the  pneumogastric  immediately 
below  the  jugular  ganglion,  and  con- 
tributes to  the  formation  of  the  pha- 
ryngeal .  nerve ;  the  larger  or  true 
continuation  of  the  nerve  passes 
backwards  behind  the  internal  jugu- 
lar vein,  and  descends  obliquely  to  the  upper  part  of  the  sterno-mastoid 
muscle.  It  pierces  the  sterno-mastoid,  and  then  passes  obliquely  across 
the  neck,  communicating  with  the  second,  third,  and  fourth  cervical 
nerves,  and  is  distributed  to  the  trapezius.  The  spinal  accessory  sends 
numerous  twigs  to  the  sterno-mastoid  in  its  passage  through  that  muscle, 
and  in  the  trapezius  the  nervous  filaments  may  be  traced  downwards  to 
its  lower  border. 

The  pneumogastric  and  spinal  accessory  nerves  together  (nervus  vagus 
cum  accessorio)  resemble  a  spinal  nerve,  of  which  the  former  with  its 
ganglion  is  the  posterior  and  sensitive  root,  the  latter  the  anterior  and 
motor  root. 

NINTH  PAiR.f  HYPOGLOSSAL  NEJIVE  (lingual).  The  hypoglossal  nerve 
arises  from  the  groove  between  the  corpus  pyramidale  and  corpus  olivare 

*  The  anatomy  of  the  side  of  the  neck,  showing  the  nerves  of  the  tongue.  1.  A  frag- 
ment of  the  temporal  bone  containing  the  meatus  auditorius  externus,  mastoid,  and  sty- 
loid  process.  2.  The  stylo-hyoid  muscle.  3.  The  stylo-glossus.  4.  The  stylo-pharyn- 
geus.  5.  The  tongue.  6.  The  hyo-glossus  muscle ;  its  two  portions.  7.  The  genio-hyo- 
glossus  muscle.  8.  The  genio-hyoideus ;  they  both  arise  from  the  inner  surface  of  the 
symphysis  of  the  lower  jaw.  9.  The  sterno-hyoid  muscle.  10.  The  sterno-thyroid. 
11.  The  thyro-hyoid,  upon  which  the  thyro-hyoidean  branch  of  the  hypoglossal  nerve  is 
si-en  ramifying.  12.  The  omo-hyoid  crossing  the  common  carotid  artery  (13),  and  in 
'.ernal  jugular  vein  (14).  15.  The  external  carotid  giving  off  its  branches.  16.  The 
internal  carotid.  18.  The  gustatory  nerve  giving  off  a  branch  to  the  submaxillary  gan 
glion  (18),  and  communicating  a  little  further  on  with  the  hypoglossal  nerve.  19.  The 
submaxillary,  or  Wharton's  duct,  passing  forwards  to  the  sublingual  gland.  20.  The 
giosso-pharyngeal  nerve,  passing  in  behind  the  hyo-glossus  muscle.  21.  The  hypoglos- 
sal nerve  curving  around  the  occipital  artery.  22.  The  descendens  noni  nerve,  form- 
ing a  loop  with  (23)  the  communicans  noni,  which  is  seen  to  be  arising  by  fila- 
ments from  the  upper  cervical  nerves.  24.  The  pneumogastric  nerve,  emerging  from 
1'etween  the  internal  jugular  vein  and  common  carotid  artery,  and  entering  the  chest. 
';"}.  The  fnr^al  n^rve,  emerging  from  the  stylo-mastoid  foramen,  and  crossing  the  exter- 
nal carotid  artery. 

t  The  twelfth  pair  according  to  the  arrangement  of  Soemmenng. 


SPINAL    NERVES.  409 

Dy  ten  or  fifteen  filaments,  which  being  collected  into  tvvo  bundles,  escape 
from  the  cranium  through  the  anterior  condyloid  foramen.  The  nerve 
then  passes  forwards  between  the  internal  carotid  artery  and  internal  jugu- 
lar vein,  and  descends  along  the  anterior  and  inner  side  of  .the  vein  to  a 
point  parallel  with  the  angle  of  the  lower  jaw.  It  next  curves  inwards 
around  the  occipital  artery,  with  which  it  forms  a  loop,  and  crossing  the 
lower  part  of  the  hyo-glossus  muscle  to  the  genio^hyo-glossus,  sends  fila- 
ments onwards  with  the  anterior  fibres  of  that  muscle  as  far  as  the  tip  of 
the  tongue.  It  is  distributed  to  the  muscles  of  the  tongue,  and  principally 
to  the  genio-hyo-glossus.  While  resting  on  the  hyo-glossus  muscle  it  is 
flattened,  and  beneath  the  mylo-hyoideus  it  communicates  with  the  gusta- 
tory nerve. 

At  its  origin  the  hypoglossal  nerve  sometimes  communicates  with  the 
posterior  root  of  the  first  cervical  nerve. 

The  Branches  of  the  hypoglossal  nerve  are  : 

Communicating  branches  with  the  Pneumogastric, 

Spinal  accessory, 
First  and  second  cervical  nerves, 
Sympathetic. 

Descendens  noni, 

Thyro-hyoidean  branch, 

Communicating  filaments  with  the  gustatory  nerve. 

The  Communications  with  the  pneumogastric  and  spinal  accessory  take 
place  through  the  medium  of  a  plexiform  interlacement  of  branches  at  the 
base  of  the  skull,  behind  the  internal  jugular  vein.  The  communications 
with  the  sympathetic  nerve  are  derived  from  the  superior  cervical  ganglion. 

The  Descendens  noni  is  a  long  and  slender  twig,  which  quits  the  hypo- 
glossal  just  as  that  nerve  is  about  to  form  its  arch  around  the  occipital 
artery,  and  descends  upon  the  sheath  of  the  carotid  vessels.  Just  below 
the  middle  of  the  neck  it  forms  a  loop  with  a  long  branch  (communicans 
noni)  from  the  second  and  third  cervical  nerves.  From  the  convexity  of 
this  loop  branches  are  sent  to  the  sterno-hyoideus,  sterno-thyroideus,  and 
both  bellies  of  the  omo-hyoideus  ;  sometimes  also  a  twig  is  given  off  to 
the  cardiac  plexus,  and  occasionally  one  to  the  phrenic  nerve.  If  the 
descendens  noni  be  traced  to  its  origin  it  will  be  found  to  be  formed  by  a 
branch  from  the  hypoglossal,  and  one  from  the  first  and  second  cervical 
nerves  ;  occasionally  it  receives  also  a  filament  from  the  pneumogastric. 

The  Thyro-hyoidean  nerve  is  a  small  branch,  distributed  to  the  thyro 
hyoideus  muscle.     It  is  given  off  from  the  trunk  of  the  hypoglossal  near 
the  posterior  border  of  the  hyoglossus  muscle,  and  descends  obliquely 
over  the  great  cornu  of  the  os  hyoides. 

The  Communicating  filaments,  with  the  gustatory  nerve,  are  several 
small  twigs,  which  ascend  upon  the  hyoglossus  muscle  near  its  anterior 
border,  and  form  a  kind  of  plexus  with  filaments  sent  down  by  the  gusta- 
tory nerve. 

SPINAL    NERVES. 

There  are  thirty-one  pairs  of  spinal  nerves,  each  arising  by  two  roots, 
an  anterior  or  motor  root,  and  a  posterior  or  sensitive  root. 

The  anterior  roots  proceed  from  a  narrow  white  line,  anterior  lateral 
35 


Fig.  185.» 


410  CERVICAL    NERVES. 

sulcus,  on  the  antero-lateral  column  of  the  spinal  cord,  and  gradually  ap- 
proach towards  the  anterior  longitudinal  fissure  as  they  descend. 

The  posterior  roots,  more  regular  than  the 
anterior,  proceed  from  the  posterior  lateral 
sulcus,  a  narrow  grey  stria,  formed  by  the  in- 
ternal grey  substance  of  the  cord.  They  are 
larger,  and  the  filaments  of  origin  more  nu- 
merous than  those  of  the  anterior  roots.  In 
the  intervertebral  foramina  there  is  a  ganglion 
on  each  of  the  posterior  roots.  The  first  cer- 
vical nerve  forms  an  exception  to  these  cha- 
racters ;  its  posterior  root  is  smaller  than  the 
anterior;  it  often  joins  in  whole  or  in  part 
with  the  spinal  accessory  nerve  and  some- 
times with  the  hypoglossal :  there  is  frequently 
no  ganglion  upon  it,  and  when  the  ganglion 
exists  it  is  often  situated  within  the  dura 
rnater,  the  latter  being  the  usual  position  of  the  ganglia  of  the  last  two  pairs 
of  spinal  nerves. 

After  the  formation  of  a  ganglion,  the  two  roots  unite  and  constitute  a 
spinal  nerve,  which  escapes  through  the  intervertebral  foramen  and  divides 
into  an  anterior  branch  for  the  supply  of  the  front  aspect  of  the  body,  and 
a  posterior  branch  for  the  posterior  aspect.  In  the  first  cervical  and  two 
last  sacral  nerves  this  division  takes  place  within  the  dura  mater  and  in 
the  upper  four  sacral  nerves  externally  to  that  cavity,  but  within  the  sacral 
canal.  The  anterior  branches,  with  the  exception  of  the  first  two  cervical 
nerves,  are  larger  than  the  posterior ;  an  arrangement  which  is  propor- 
tioned to  the  larger  extent  of  surface  they  are  required  to  supply. 
The  Spinal  nerves  are  divided  into — 


Cervical 
Dorsal 
Lumbar 
Sacral 


12 
5 
6 


pairs. 


The  cervical  nerves  pass  off  transversely  from  the  spinal  cord ;  the  dor- 
sal are  oblique  in  their  direction ;  and  the  lumbar  and  sacral  vertical ;  the 
latter  form  the  large  assemblage  of  nerves  at  the  termination  of  the  cord 
called  cauda  equina. 

CERVICAL    NERVES. 

The  cervical  nerves  increase  in  size  from  above  downwards ;  the  first 
(sub-occipital)  passes  out  of  the  spinal  canal  between  the  occipital  bone 
and  the  atlas ;  and  the  last,  between  the  last  cervical  and  first  dorsal  ver- 

*  Part  of  the  cervical  portion  of  the  spinal  cord,  viewed  on  its  posterior  aspect;  and 
showing  its  membranes  and  the  posterior  roots  of  the  spinal  nerves.  1,  1.  The  fissura 
longitudinalis  posterior.  2,  2.  The  posterior  roots  of  the  cervical  nerves ;  on  the  oppo- 
site side  the  corresponding  roots  are  cut  through  near  their  origin.  3,  3.  The  membrana 
dentata.  4.  The  nervus  accessorius,  ascending  between  the  posterior  roots  and  the 
membrana  dentata;  on  the  opposite  side  this  nerve  has  been  removed.  5,  5.  The  dura 
inater  or  thcca  vertebralis.  6,  6.  Openings  in  the  dura  mater  for  the  passage  of  the 
roots  of  the  nerves.  7,  7.  The  ganglia  on  the  posterior  roots  of  the  spinal  nerves.  8. 
Ihe  antenor  roots  of  the  spinal  nerves.  The  posterior  roots  have  been  cut  away  in 
wrder  to  show  each  anterior  root,  proceeding  to  join  the  nerve  beyond  the  ganglion. 


CERVICAL    PLEXUS.  411 

tebra.  Each  nerve,  at  its  escape  from  the  intervertebral  foramen,  divides 
into  an  anterior  and  a  posterior  branch.  The  anterior  branches  of  the  four 
upper  cervical  nerves  form  the  cervical  plexus ;  the  posterior  branches,  the 
posterior  cervical  plexus.  The  anterior  branches  of  the  four  inferior  cer- 
vical, together  with  the  first  dorsal,  form  the  brachial  plexus. 

ANTERIOR  CERVICAL  NERVES. — The  anterior  branch  of  \hefirst  cervical 
nerve  escapes  from  the  vertebral  canal  through  the  groove  upon  the  poste- 
rior arch  of  the  atlas  which  supports  the  vertebral  artery,  beneath  which  it 
lies.  It  then  descends  in  front  of  the  transverse  process  of  the  atlas,  sends 
several  twigs  to  the  rectus  lateralis  and  recti  antici,  and  forms  an  anasto- 
motic  loop  by  communicating  with  an  ascending  branch  of  the  second 
nerve. 

The  anterior  branch  of  the  second  cervical  nerve  at  its  exit  from  the  in- 
tervertebral foramen  between  the  atlas  and  the  axis,  gives  twigs  to  the 
rectus  anticus  major,  scalenus  posticus  and  levator  anguli  scapulae  mus- 
cles, and  divides  into  three  branches,  viz.  an  ascending  branch,  which 
completes  the  arch  of  communication  with  the  first  nerve ;  and  two  de- 
scending branches,  which  communicate  with  the  third  nerve. 

The  anterior  branch  of  the  third  cervical  nerve,  double  the  size  of  the 
preceding,  divides  at  its  exit  from  the  intervertebral  foramen  into  numer- 
ous branches,  some  of  which  are  distributed  to  the  rectus  major,  Jongus 
colli,  and  scalenus  posticus  muscles,  while  others  communicate  and  form 
loops  and  anastomoses  with  the  second  and  fourth  nerve. 

The  anterior  branch  of  the  fourth  cervical  nerve,  of  the  same  size  with 
the  preceding,  sends  twigs  to  the  rectus  major,  longus  colli,  and  levator 
anguli  scapulae,  communicates  by  anastomosis  with  the  third,  and  sends  a 
small  branch  downwards  to  the  fifth  nerve.  Its  principal  branches  pass 
downwards  and  outwards  across  the  posterior  triangle  of  the  neck,  to- 
wards the  clavicle  and  acromion. 

The  anterior  branches  of  the  fifth,  sixth,  seventh,  and  eighth  cervical 
nerves  will  be  described  with  the  brachial  plexus,  of  which  they  form  a 
part. 

CERVICAL    PLEXUS. 

The  cervical  plexus  is  constituted  by  the  loops  of  communication,  and 
by  the  anastomoses  which  take  place  between  the  anterior  branches  of  the 
four  first  cervical  nerves.  The  plexus  rests  upon  the  levator  anguli  sca- 
pulae, posterior  scalenus,  and  splenius  muscle,  and  is  covered  in  by  the 
sterno-mastoid  and  platysma. 

The  Branches  of  the  cervical  plexus  may  be  arranged  into  three  groups, 
superficial  ascending,  superficial  descending ;  and  deep — 

C  Superficialis  colli, 
f  Ascending,     <  Auricular  is  magnus, 

o        n  •  i  f  Occipitalis  minor. 

Superficial     <  r  A         •  i 

ri          ,.  \  Acromiales, 

{Descending,  j  Claviculare's. 

{Communicating  branches, 
Muscular, 
Communicans  nom, 
Phrenic. 


412  CERVICAL    PLEXUS. 

The  Superfidalis  colli  is  formed  by  communicating  branches  from  the 
second  and  third  cervical  nerves ;  it  curves  around  the  posterior  border 
of  the  sterno-mastoid  and  crosses  obliquely  behind  the  external  jugular 
vein  to  the  anterior  border  of  that  muscle,  where  it  divides  into  an  ascend-  . 
ing  and  a  descending  branch  ;  the  descending  branch  is  distributed  to  the 
integument  on  the  side  and  front  of  the  neck,  as  low  down  as  the  clavicle  ; 
the  ascending  branch  passes  upwards  to  the  subm axillary  region,  and 
divides  into  four  or  five  filaments,  some  of  which  pierce  the  platysma 
myoides  and  supply  the  integument  as  high  up  as  the  chin  and  lower  part 
of  the  face,  while  others  form  a  plexus  with  the  descending  branches  of 
the  facial  nerve  beneath  the  platysma.  One  or  two  filaments  from  this 
nerve  accompany  the  external  jugular  vein. 

The  Jluricularis  magnus,  the  largest  of  the  three  ascending  branches  of 
the  cervical  plexus,  also  proceeds  from  the  second  and  third  cervical 
nerve ;  it  curves  around  the  posterior  border  of  the  sterno-mastoid,  and 
ascends  upon  that  muscle,  lying  parallel  with  the  external  jugular  vein,  to 
the  parotid  gland,  where  it  divides  into  an  anterior  and  a  posterior  branch. 
The  anterior  branch  is  distributed  to  the  integument  over  the  parotid 
gland,  to  the  gland  itself,  communicating  with  the  facial  nerve,  and  to  the 
external  ear.  The  posterior  branch  pierces  the  parotid  gland  and  crosses 
the  mastoid  process,  where  it  divides  into  branches  which  supply  the  pos- 
terior part  of  the  pinna  and  the  integument  of  the  side  of  the  head,  and 
communicate  with  the  posterior  auricular  branch  of  the  facial  and  with 
the  occipitalis  minor.  Previously  to  its  division  the  auricularis  magnus 
nerve  sends  off  several  facial  branches  which  are  distributed  to  the  cheek. 

The  Occipitalis  minor  arises  from  the  second  cervical  nerve ;  it  curves 
around  the  posterior  border  of  the  sterno-mastoid  above  the  preceding, 
and  ascends  upon  that  muscle,  parallel  with  its  posterior  border,  to  the 
lateral  and  posterior  side  of  the  head.  It  is  distributed  to  the  integument 
and  to  the  muscles  of  this  region,  namely,  to  the  occipito-frontalis,  attollens 
and  attrahens  aurem,  and  communicates  with  the  occipitalis  major,  auri- 
cularis magnus  and  posterior  auricular  branch  of  the  facial. 

The  Acromiales  and  Claviculares  are  two  or  three  large  nerves  which 
proceed  from  the  fourth  cervical  nerve,  and  divide  into  numerous  branches 
which  pass  downwards  over  the  clavicle,  and  are  distributed  to  the  inte- 
gument of  the  upper  and  anterior  part  of  the  chest  from  the  sternum  to  the 
shoulder. 

The  Communicating  branches  are  filaments  which  arise  from  the  loop 
between  the  first  and  second  cervical  nerve,  and  pass  inwards  to  commu- 
nicate with  the  sympathetic,  the  pneumogastric,  and  the  hypo-glossal 
nerve.  The  three  first  cervical  nerves  send  branches  to  the  first  cervical 
ganglion  ;  the  fourth  sends  a  branch  to  the  trunk  of  the  sympathetic,  or 
to  the  middle  cervical  ganglion.  From  the  second  cervical  nerve  a  large 
branch  is  given  off  which  goes  to  join  the  spinal  accessory  nerve. 

The  Muscular  branches  proceed  from  the  third  and  fourth  cervical 
nerves;  they  aie  distributed  to  the  trapezius,  levator  anguli  scapula?,  and 
rhomboidei  muscles. 

The  Communicans  noni  is  a  long  slender  branch  formed  by  filaments 
from  the  first,  second,  and  third  cervical  nerves ;  it  descends  upon  the 
outer  side  of  the  internal  jugular  vein,  and  forms  a  loop  with  the  descen- 
dens  noni  ovor  the  sheath  of  the  carotid  vessels. 


POSTERIOR    CERVICAL    PLEXUS.  413 

The  Phrenic  nerve  (internal  respiratory  of  Bell)  is  formed  by  filaments 
from  the  third,  fourth,  and  fifth  cervical  nerves,  receiving  also  a  branch 
from  the  sympathetic.  It  descends  to  the  root  of  the  neck,  resting  upon 
the  scalenus  anticus  muscle,  then  crosses  the  first  portion  of  the  subclavian 
artery,  and  enters  the  chest  between  it  and  the  subclavian  vein.  Within 
the  chest  it  passes  through  the  middle  mediastinum,  between  the  pleura 
and  pericardium,  and  in  front  of  the  root  of  the  lung  to  the  diaphragm  to 
which  it  is  distributed,  some  of  its  filaments  reaching  the  abdomen  through 
the  openings  for  the  ossophagus  and  vena  cava,  and  communicating  with 
the  phrenic  and  solar  plexus,  and  on  the  right  side  with  the  hepatic  plexus. 
The  left  phrenic  nerve  is  rather  longer  than  the  right,  from  the  inclination 
of  the  heart  to  the  left  side. 

POSTERIOR  CERVICAL  NERVES. — The  posterior  division  of  the  first  cer- 
vical nerve  (sub-occipital),  larger  than  the  anterior,  escapes  from  the  ver- 
tebral canal  through  the  opening  for  the  vertebral  artery,  lying  posteriorly 
to  that  vessel,  and  emerges  into  the  triangular  space  formed  by  the  rectus 
posticus  major,  obliquus  superior,  and  obliquus  inferior.  It  is  distributed 
to  the  recti  and  obliqui  muscles,  and  sends  one  or  two  filaments  down- 
wards to  communicate  with  the  second  cervical  nerve.  The  posterior 
branch  of  the  second  cervical  nerve  is  three  or  four  times  greater  than  the 
anterior  branch,  and  is  larger  than  the  other  posterior  cervical  nerves. 
The  posterior  branch  of  the  third  cervical  nerve  is  smaller  than  the  preced- 
ing, but  larger  than  the  fourth  ;  and  the  other  posterior  cervical  nerves  go 
on  progressively  decreasing  to  the  seventh.  The  posterior  branches  of 
the  fourth,  fifth,  sixth,  seventh  and  eighth  nerves  pass  inwards  between 
the  muscles  of  the  back  in  the  cervical  and  upper  part  of  the  dorsal  region, 
and  reaching  the  surface  near  the  middle  line,  are  reflected  outwards,  to 
be  distributed  to  the  integument.  The  fourth  and  fifth  are  nearly  trans- 
verse in  their  course,  and  lie  between  the  semispinalis  colli  and  complexus. 
The  sixth,  seventh,  and  eighth  are  directed  nearly  vertically  downwards  j 
they  pierce  the  aponeurosis  of  origin  of  the  splenius  and  trapezius. 

POSTERIOR  CERVICAL  PLEXUS. — This  plexus  is  constituted  by  the  suc- 
cession of  anastomosing  loops  and  communications  wrhich  pass  between 
the  posterior  branches  of  the  first,  second,  and  third  cervical  nerves.  It 
is  situated  between  the  complexus  and  semispinalis  colli,  and  its  branches 
are  the — 

Musculo-cutaneous,  Occipitalis  major. 

The  Musculo-cutaneous  branches  pass  inwards  between  the  complexus 
and  semispinalis  colli  to  the  ligamentum  nuchae,  distributing  muscular 
filaments  in  their  course.  They  then  pierce  the  aponeurosis  of  the  trape- 
eius  and  become  subcutaneous,  sending  branches  outwards  to  supply  the 
integument  of  the  posterior  aspect  of  the  neck,  and  upwards  to  the  poste- 
rior region  of  the  scalp. 

The  Occipitalis  major  is  the  direct  continuation  of  the  second  cervical 
nerve ;  it  ascends  obliquely  inwards,  between  the  obliquus  inferior  and 
complexus,  pierces  the  complexus  and  trapezius  after  passing  for  a  short 
distance  between  them,  and  ascends  upon  the  posterior  aspect  of  the  head 
between  the  integument  and  occipito-frontalis,  in  company  with  the  occi- 
35* 


414 


BRACHIAL    PLEXUS. 


Fig.  186.» 


pital  artery.  The  occipitalis  majoi 
sends  numerous  branches  to  the  mus- 
cles of  the  neck,  and  is  distributed 
to  the  integument  of  the  scalp,  as  far 
forwards  as  the  middle  of  the  vertex 
of  the  head.  Its  branches  commu- 
nicate with  those  of  the  occipitalis 
minor. 

BRACHIAL    PLEXUS. 

The  Brachial  or  axillary  plexus  of 
nerves  is  formed  by  communications 
between  the  anterior  branches  of  the 
four  last  cervical  and  first  dorsal 
nerve.  These  nerves  are  all  similar 
in  size,  and  their  mode  of  disposition 
in  the  formation  of  the  plexus  is  the 
following :  the  fifth  and  sixth  nerves 
unite  to  form  a  common  trunk,  which 
soon  divides  into  two  branches  ;  the 
last  cervical  and  first  dorsal  also 
unite  immediately  upon  their  exit 
from  the  intervertebral  foramina,  and 
the  common  trunk  resulting  from  their 
union  after  a  short  course  also  di- 
vides into  two  branches ;  the  seventh 
nerve  passes  outwards  between  the 
common  trunks  of  the  two  preceding,  and  opposite  the  clavicle  divides 
into  a  superior  branch  which  unites  with  the  inferior  division  of  the  supe- 
rior trunk,  and  an  inferior  branch  which  communicates  with  the  superior 
division  of  the  inferior  trunk :  from  these  divisions  and  communications 
the  brachial  plexus  results.  The  brachial  plexus  communicates  with  the 
cervical  plexus  by  means  of  a  branch  sent  down  from  the  fourth  to  the 
fifth  nerve,  and  by  the  inferior  branch  of  origin  of  the  phrenic  nerve,  and 
also  sends  filaments  of  communication  to  the  sympathetic.  The  plexus  is 
broad  in  the  neck,  narrows  as  it  descends  into  the  axilla,  and  again  en- 
larges at  its  lower  part  where  it  divides  into  its  six  terminal  branches. 

Relations. — The  brachial  plexus  is  in  relation  in  the  neck  with  the  t\vo 
scaleni  muscles,  between  which  its  nerves  issue ;  lower  down  it  is  placed 
between  the  clavicle  and  subclavius  muscle  above,  and  the  first  rib  and 
first  serration  of  the  serratus  magnus  muscle  below.  In  the  axilla,  it  is 
situated  at  first  to  the  outer  side  and  then  behind  the  axillary  artery,  rest- 
ing by  its  outer  border  against  the  tendon  of  the  subscapularis  muscle.  At 
this  point  it  completely  surrounds  the  artery  by  means  of  the  two  cords 
•which  are  sent  off  to  form  the  median  nerve. 

Its  Branches  may  be  arranged  into  two  groups,  humeral  and  descend- 
ing,-- 

A  view  of  the  brachial  plexus  of  nerves  and  branches  of  arm.  1,  1.  The  scalenus 
anticus  muscle,  in  front  of  which  are  the  roots  of  the  plexus.  2,  2.  The  median  nerve 
3.  The  ulnar  nerve.  4.  The  branch  to  the  biceps  muscle.  5.  The  nerves  of  Wrisbeig 
6.  The  phrenic  nerve  from  the  3d  and  4th  cervical. 


BRACHIAL    PLEXUS. 


415 


Humeral  Branches.  Descending  Branches. 

Superior  muscular,  External  cutaneous, 

Short  thoracic,  Internal  cutaneous, 

Long  thoracic,  .               Lesser  internal  cutaneous, 

Supra-scapular,  Median, 

Subscapular,  Ulnar, 

Inferior  muscular.  Musculo-spiral, 

Circumflex. 

The  superior  Muscular  nerves  are  several  large  branches  which  are  given 
off  by  the  fifth  cervical  nerve  above  the  clavicle ;  they  are,  a  subclavian 
branch  to  the  subclavius  muscle,  which  usually  sends  a  communicating 
filament  to  the  phrenic  nerve :  a  rhomboid  branch  to  the  rhomboidei  mus- 
cles ;  and  frequently  an  angular  branch  to  the  levator  anguli  scapulae. 

The  Short  thoracic  nerves  (anterior)  are  two  in  number ;  they  arise  from 
the  brachial  plexus  at  a  point  parallel  with  the  clavicle,  and  are  divisible 
into  an  anterior  and  a  posterior  branch.  The  anterior  branch  passes  for- 
wards between  the  subclavius  muscle  and  the  subclavian  vein,  and  is  dis- 
tributed to  the  pectoralis  major  muscle,  entering  it  by  its  costal  surface. 
In  its  course  it  sends  one  or  two  twigs  to  the  deltoid  muscle  and  gives  off 
a  branch  which  forms  a  loop  of  communication  with  the  posterior  branch. 
The  posterior  branch  passes  forward  beneath  the  axillary  artery  and  unites 
with  the  communicating  branch  of  the  preceding  to  form  a  loop,  from 
which  numerous  branches  are  given  off  to  the  pectoralis  major  and  pecto- 
ralis minor. 

The  Long  thoracic  nerve  (posterior  thoracic,  external  respiratory  of  Bell) 
is  a  long  and  remarkable  branch  arising  from  the  fourth  and  fifth  cervical 
nerves,  Immediately  after  their  escape  from  the  intervertebral  foramina. 
It  passes  down  behind  the  plexus  and  axillary  vessels,  resting  on  the  sca- 
lenus  posticus  muscle ;  it  then  descends  along  the  side  of  the  chest  upon 
the  serratus  magnus  muscle  to  its  lowest  serration.  It  sends  numerous 
filaments  to  this  muscle  in  its  course. 

The  Supra-scapular  nerve  arises  above  the  clavicle  from  the  fifth  cervical 
nerve  and  descends  obliquely  outwards  to  the  supra-scapular  notch ;  it 
then  passes  through  the  notch,  crosses  the  supra-spinous  fossa  beneath  the 
supra-spinatus  muscle,  and  passing  in  front  of  the  concave  margin  of  the 
spine  of  the  scapula  enters  the  infra-spinous  fossa.  It  is  distributed  to  the 
supra-spinatus  and  infra-spinatus  muscle. 

The  Subscapular  nerves  are  two  in  number ;  of  which  one  arises  from 
the  brachial  plexus  above  the  clavicle,  the  other  from  the  posterior  aspect 
of  the  plexus  within  the  axilla.  They  are  distributed  to  the  subscapularis 
muscle. 

The  Inferior  muscular  nerves  are  two  or  three  branches  which  proceed 
from  the  lower  and  back  part  of  the  brachial  plexus,  and  are  distributed 
to  the  latissimus  dorsi  and  teres  major.  The  former  of  these  is  the  longer, 
and  follows  the  course  of  the  Subscapular  artery. 

The  terminal  branches  of  the  plexus  are  arranged  in  the  following  order : 
the  external  cutaneous,  and  one  head  of  the  median  to  the  outer  side  of 
the  artery ;  the  other  head  of  the  median,  internal  cutaneous,  lesser  internal 
cutaneous,  and  ulnar,  upon  its  inner  side ;  and  the  circumflex  and  mus- 
culo-spiral  behind. 


416  MEDIAN    NERVE. 

The  EXTERNAL  CUTANEOUS  NERVE  (musculo-cutaneous,  perforans  Cas- 
serii)  arises  from  the  brachial  plexus  in  common  with  the  external  head  of 
the  median ;  it  pierces  the  coraco-brachialis  muscle  and  passes  between 
the  biceps  and  brachialis  anticus,  to  the  outer  side  of  the  bend  of  the  el 
bow,  where  it  perforates  the  fascia,  and  divides  into  an  external  and  in- 
ternal branch.  The  branches  pass  behind  the  median  cephalic  vein,  the 
external,  the  larger  of  the  two,  taking  the  course  of  the  radial  vein  and 
communicating  with  the  branches  of  the  radial  nerve  on  the  back  of  the 
hand ;  the  internal  and  smaller  following  the  direction  of  the  supinator 
longus,  communicating  with  the  internal  cutaneous,  and  at  the  lower  third 
of  the  fore-arm  sending  off  a  twig,  which  accompanies  the  radial  artery  to 
the  wrist,  and  distributes  filaments  to  the  synovial  membranes  of  the  joint. 

The  external  cutaneous  nerve  supplies  the  coraco-brachialis,  biceps  and 
brachialis  anticus  in  the  upper  arm,  and  the  integument  of  the  outer  side 
of  the  fore-arm  as  far  as  the  wrist  and  hand. 

The  INTERNAL  CUTANEOUS  NERVE  is  one  of  the  internal  and  smaller  of 
the  branches  of  the  axillary  plexus ;  it  arises  from  the  plexus  in  common 
with  the  ulnar  and  internal  head  of  the  median,  and  passes  down  the  inner 
side  of  the  arm  in  company  with  the  basilic  vein,  giving  off  several  cuta- 
neous filaments  in  its  course.  At  about  the  middle  of  the  upper  arm  it 
pierces  the  deep  fascia  by  the  side  of  the  basilic  vein  and  divides  into  two 
branches,  anterior  and  posterior.  The  anterior  branch,  the  larger  of  the 
two,  divides  into  several  branches  which  pass  in  front  of,  and  sometimes 
behind,  the  median  basilic  vein  at  the  bend  of  the  elbow,  and  descends  in 
the  course  of  the  palmaris  longus  muscle  to  the  wrist,  distributing  filaments 
to  the  integument  in  their  course  and  communicating  with  the  anterior 
branch  of  the  external  cutaneous  on  the  outer  side,  and  its  own  posterior 
branch  on  the  inner  side  of  the  fore-arm.  The  posterior  branch  sends  off 
several  twigs  to  the  integument  over  the  inner  condyle  and  olecranon,  and 
then  descends  the  fore-arm  in  the  course  of  the  ulnar  vein  as  far  as  the 
wrist,  supplying  the  integument  on  the  inner  side  of  the  fore-arm  and 
communicating  with  the  anterior  branch  of  the  same  nerve  in  front,  and 
the  dorsal  branch  of  the  ulnar  nerve  on  the  wrist. 

The  LESSER  INTERNAL  CUTANEOUS  NERVE,  or  nerve  of  Wrisberg,  the 
smallest  of  the  branches  of  the  brachial  plexus,  is  very  irregular  in  point 
of  origin.  It  is  a  long  and  slender  nerve,  and  usually  arises  from  the 
common  trunk  of  the  last  cervical  and  first  dorsal  nerve.  Passing  down- 
wards into  the  axillary  space  it  communicates  with  the  external  branch 
of  the  first  intercosto-humeral  nerve,  and  descends  on  the  inner  side  of 
the  internal  cutaneous  nerve,  to  the  middle  of  the  posterior  aspect  of  the 
upper  arm,  where  it  pierces  the  fascia  and  is  distributed  to  the  integument 
of  the  elbow,  communicating  with  filaments  of  the  posterior  branch  of  the 
"nternal  cutaneous  and  with  the  spiral  cutaneous.  In  its  course  it  gives 
off  two  or  three  cutaneous  filaments  to  the  integument  of  the  inner  and 
anterior  aspect  of  the  upper  arm. 

The  MEDIAN  NERVE  has  received  its  name  from  taking  a  course  along 
tne  middle  of  the  fore-arm  to  the  palm  of  the  hand  ;  it  is,  therefore,  inter- 
mediate in  position  between  the  radial  and  ulnar  nerves.  It  commences 
by  two  heads,  which  embrace  the  axillary  artery ;  lies  at  first  to  the  outer 
side  of  the  brachial  artery,  which  it  crosses  at  its  middle ;  and  descends 


MEDIAN    NERVE.  417 

on  its  inner  side  to  the  bend  of  the  elbow.     It  Fig.  187* 

then  passes  between  the  two  heads  of  the  pronator 

radii  teres  and  flexor  sublimis  digitorum  muscles, 

and  runs  down  the  fore-arm,  between  the  flexor 

sublimis  and  profundus,  and  beneath  the  annular 

ligament,  into  the  palm  of  the  hand. 

The  Branches  of  the  median  nerve  are, — 

Muscular, 

Anterior  interosseous, 
Superficial  palmar, 
Digital. 

The  Muscular  branches  are  given  off  by  the 
nerve  at  the  bend  of  the  elbow  ;  they  are  distri- 
buted to  all  the  muscles  on  the  anterior  aspect 
of  the  fore-arm,  with  the  exception  of  the  flexor 
carpi  ulnaris,  and  to  the  periosteum.  The  branch 
to  the  pronator  radii  teres  sends  off  reflected 
branches  to  the  elbow  joint. 

The  Anterior  interosseous  is  a  large  branch  ac- 
companying the  anterior  interosseous  artery,  and 
supplying  the  deep  layer  of  muscles  in  the  fore- 
arm. It  passes  beneath  the  pronator  quadratus 
muscle,  and  pierces  the  interosseous  membrane 
near  the  wrist.  On  reaching  the  posterior  aspect 
of  the  wrist  it  joins  a  large  and  remarkable 
ganglion  which  gives  off  a  number  of  branches  for 
the  supply  of  the  joint. 

The  Superficial  palmar  branch  arises  from  the  median  nerve  at  about 
the  lower  fourth  of  the  fore-arm  :  it  crosses  the  annular  ligament,  and  is 
distributed  to  the  integument  over  the  ball  of  the  thumb  and  in  the  palm 
of  the  hand. 

The  median  nerve  at  its  termination  in  the  palm  of  the  hand  is  spread 
out  and  flattened,  and  divides  into  six  branches,  one  muscular  and  five 
digital.  The  muscular  branch  is  distributed  to  the  muscles  of  the  ball  of 
the  thumb.  The  digital  branches  send  twigs  to  the  lumbricales  muscles 
and  are  thus  arranged :  two  pass  outwards  to  the  thumb  to  supply  its 
borders;  one  to  the  radial  side  of  the  index  finger;  one  subdivides  for 
the  supply  of  the  adjoining  sides  of  the  index  and  middle  fingers ;  and 
the  >-einaimng  one,  for  the  supply  of  the  adjoining  sides  of  the  middle  and 
ring-  fingers.  The  digital  nerves  in  their  course  along  the  fingers  are 
situated  to  the  inner  side  cf  the  digital  arteries.  Opposite  the  base  of  the 
first  phalanx  each  nerve  gives  off  a  dorsal  branch  which  runs  along  the 
border  of  the  dorsum  of  the  finger.  Near  the  extremity  of  the  finger  the 
digital  nerve  divides  into  a  palmar  and  a  dorsal  branch ;  the  former  sup- 
plying the  sentient  extremity  of  the  finger,  and  the  latter  the  structures 
around  and  beneath  the  nail.  The  digital  nerve  maintains  no  communica- 
tion with  its  fellow  of  the  opposite  side. 

*  Nerves  of  front  of  fore-arm.  1.  Median  nerve.  2.  Anterior  branch  of  musculei 
spiral  or  radial  nerve.  3.  Ulnar  nerve.  4.  Division  of  median  nerve  in  the  palrn 
to  the  thumb,  1st,  2d,  and  radial  side  of  3d  finger.  5.  Division  of  ulnar  nerve  to  ui:aw 
•ide  of  3d  and  both  sides  of  4th  finger. 

2u 


418 


ULNAR    NERVE. 


The  ULNAR  NERVE  is  somewhat  smaller  than  the  median,  behind  wmcn 
it  lies,  gradually  diverging  from  it  in  its  course.  It  arises  from  the  bra- 
chial  plexus  in  common  with  the  internal  head  of  the  median  and  the  in- 
ternal cutaneous  nerve,  and  runs  down  the  inner  side  of  the  arm,  to  the 
groove  between  the  internal  condyle  and  olecranon,  resting  upon  the 
internal  head  of  the  triceps,  and  accompanied  by  the  inferior  profunda 
artery.  At  the  elbow  it  is  superficial,  and  supported  by  the  inner  con- 
dyle, against  whicH  it  is  easily  compressed,  giving  rise  to  the  thrilling 
sensation  along  the  inner  side  of  the  fore-arm  and  little  finger,  ascribed  to 
striking  the  "  funny  bone."  It  then  passes  between  the  two  heads  of  the 
flexor  carpi  ulnaris  and  descends  along  the  inner  side  of  the  fore-arm, 
crosses  the  annular  ligament,  and  divides  into  two  branches,  superficial 
and  deep  palmar.  At  the  commencement  of  the  middle  third  of  the  fore- 
arm, it  becomes  applied  against  the  artery,  and  lies  to  its  ulnar  side,  as 
far  as  the  hand. 

The  Branches  of  the  ulnar  nerve  are — 

Fig.  188.» 

Muscular  in  the  upper  arm, 

Articular, 

Muscular  in  the  fore-arm, 

Anastomotic, 

Dorsal  branch, 

Superficial  palmar, 

Deep  palmar. 

The  Muscular  branches  in  the  upper  arm  are  a 
few  filaments  distributed  to  the  triceps. 

The  Jlrticular  branches  are  several  filaments  to 
the  elbow  joint,  which  are  given  off  from  the  nerve 
as  it  lies  in  the  groove  between  the  inner  condyle 
and  the  olecranon. 

The  Muscular  branches  in  the  fore-arm  are  dis- 
tributed to  the  flexor  carpi  ulnaris  and  flexor  pro- 
fun  dus  digitorum  muscle. 

The  Jlnastomotic  branch  (n.  cutaneus  palmans 
ulnaris)  is  a  small  nerve  which  arises  from  the  ulnar 
at  about  the  middle  of  the  fore-arm,  and  divides 
into  a  deep  and  a  superficial  bianch ;  the  former  ac- 
companies the  ulnar  artery,  the  latter  pierces  the 
deep  fascia,  and  is  distributed  to  the  integument, 
1  communicating  with  the  posterior  branch  of  the  in- 
ternal cutaneous  nerve. 

The  Dorsal  branch  passes  backwards  beneath  the 
tendon  of  the  flexor  carpi  ulnaris,  at  the  lower  third 
of  the  fore-arm,  and  divides  into  branches,  which 
supply  the  integument  and  two  fingers  and  a  half  on  the  posterior  aspect 
of  the  hand,  communicating  with  the  internal  cutaneous  and  radial  nerve. 
Tne  Superficial  palmar  branch  divides  into  three  filaments,  which  are 

*  A  view  of  the  nerves  on  the  dorsal  aspect  of  the  fore-arm  and  hand.  1,  1.  The  ulnar 
nerve.  2,  2.  The  posterior  interosseous  nerve.  3.  Termination  of  the  nervus  cutaneus 
burner!.  4.  The  dorsalis  carpi,  a  branch  of  the  radial  nerve.  5,  5.  A  back  view  of  the 
digital  nerves.  6.  Dorsal  branch  of  the  ulnar  nerve. 


MUSCULO-SPIRAL   NERVE.  419 

distributed,  one  to  the  ulnar  side  of  the  little  finger,  one  to  the  adjoining 
borders  of  the  little  and  ring  fingers,  and  a  communicating  branch  to  join 
the  median  nerve. 

The  Deep  palmar  branch  passes  between  the  abductor  and  flexor 
minimi  digiti,  to  the  deep  palmar  arch,  supplying  the  muscles  of  the  little 
finger,  and  the  interossei  and  other  deep  structures  in  the  palm  of  the 
hand. 

The  MUSCULO-SPIRAL  NERVE,  the  largest  branch  of  the  brachial  plexus, 
arises  from  the  posterior  part  of  the  plexus  by  a  common  trunk  with  the 
circumflex  nerve.  It  passes  downwards  from  its  origin  in  front  of  the 
tendons  of  the  latissimus  dorsi  and  teres  major  muscle,  and  winds  around 
the  humerus  in  the  spiral  groove,  accompanied  by  the  superior  profunda 
artery,  to  the  space  between  the  brachialis  anticus  and  supinator  longus, 
and  thence  onwards  to  the  bend  of  the  elbow,  where  it  divides  into  two 
branches,  the  posterior  interosseous  and  radial  nerve. 

The  Branches  of  the  musculo-spiral  nerve  are — 

Muscular,  Spiral  cutaneous, 

Radial,  Posterior  interosseous. 

The  Muscular  branches  are  distributed  to  the  triceps,  to  the  supinator 
longus,  and  to  the  extensor  carpi  radialis  longior. 

The  Spiral  cutaneous  nerve  pierces  the  deep  fascia  immediately  below 
the  insertion  of  the  deltoid  muscle,  and  passes  down  the  outer  side  of  the 
fore-arm  as  far  as  the  wrist.  It  is  distributed  to  the  integument. 

The  Radial  nerve  runs  along  the  radial  side  of  the  fore-arm  to  the  com- 
mencement of  its  lower  third ;  it  then  passes  beneath  the  tendon  of  the 
supinator  longus,  and  at  about  two  inches  above  the  wrist  joint  pierces 
the  deep  fascia,  and  divides  into  an  external  and  an  internal  branch. 
The  external  branch,  the  smaller  of  the  two,  is  distributed  to  the  outer 
border  of  the  hand  and  thumb,  and  communicates  with  the  posterior 
branch  of  the  external  cutaneous  nerve.  The  internal  branch  crosses  the 
direction  of  the  extensor  tendons  of  the  thumb,  and  divides  into  several 
filaments  for  the  supply  of  the  ulnar  border  of  the  thumb,  the  radial  border 
of  the  index  finger,  and  the  adjoining  borders  of  the  index  and  middle 
fingers.  It  communicates  on  the  back  of  the  hand  with  the  dorsal  branch 
of  the  ulnar  nerve. 

In  the  upper  third  of  the  fore-arm  the  radial  nerve  lies  beneath  the 
border  of  the  supinator  longus  muscle.  In  the  middle  third  it  is  in  rela- 
tion with  the  radial  artery  lying  to  its  outer  side.  It  then  quits  the  artery, 
and  passes  beneath  the  tendon  of  the  supinator  longus,  to  reach  the  back 
of  the  hand. 

The  Posterior  interosseous  nerve,  somewhat  larger  than  the  radial,  sepa- 
rates from  the  latter  at  the  bend  of  the  elbow,  pierces  the  supinator  brevis 
muscle,  and  emerges  from  its  lower  border  on  the  posterior  aspect  of  the 
fore-arm,  where  it  divides  into  branches  which  supply  the  whole  of  the 
muscles  on  the  posterior  aspect  of  the  fore-arm.  One  branch,  longer  than 
the  rest,  descends  to  the  posterior  part  of  the  wrist,  and  forms  a  large 
gangliform  swelling  (the  common  character  of  nerves  which  supply  joints) 
from  which  numerous  branches  are  distributed  to  the  wrist  joint 


420  DORSAL    NERVES. 

The  CIRCUMFLEX  NERVE  arises  from  the  posterior  part  of  the  brachial 
plexus  by  a  common  trunk  with  the  musculo-spiral  nerve.  It  passes 
downwards  over  the  border  of  the  subscapularis  muscle,  winds  around 
the  neck  of  the  humerus  with  the  posterior  circumflex  artery,  and  ter- 
minates by  dividing  into  numerous  branches,  which  supply  the  deltoid 
muscle. 

The  Branches  gf  the  circumflex  nerve  are  muscular  and  cutaneous 
The  Muscular  branches  are  distributed  to  the  subscapularis,  teres  minor 
teres  major,  latissimus  dorsi,  and  deltoid.  The  Cutaneous  branches 
pierce  the  deltoid  muscle,  and  are  distributed  to  the  integument  of  the 
shoulder.  One  of  these  cutaneous  branches  (cutaneus  brachii  superior), 
larger  than  the  rest,  winds  around  the  posterior  border  of  the  deltoid,  and 
divides  into  filaments  which  pass  in  a  radiating  direction  across  the 
shoulder,  and  are  distributed  to  the  integument. 

DORSAL    NERVES. 

The  dorsal  nerves  are  twelve  in  number  on  each  side ;  the  first  appears 
between  the  first  and  second  dorsal  vertebrae,  and  the  last  between  the 
twelfth  dorsal  and  first  lumbar.  They  are  smaller  than  the  lower  cervical 
nerves,  and  diminish  gradually  in  size  from  the  first  to  the  tenth,  and  then 
increase  to  the  twelfth.  Each  nerve,  as  soon  as  it  has  escaped  from  the 
intervertebral  foramen,  divides  into  two  branches ;  a  dorsal  branch  and 
the  true  intercostal  nerve. 

The  Dorsal  branches  pass  directly  backwards  between  the  transverse 
processes  of  the  vertebrae,  lying  internally  to  the  anterior  costo-transverse 
ligament,  where  each  nerve  divides  into  an  anterior  or  muscular  and  a 
posterior  or  musculo-cutaneous  branch.  The  muscular  branch  enters  the 
substance  of  the  muscles  in  the  direction  of  a  line  corresponding  with  the 
interval  of  separation  between  the  longissimus  dorsi  and  sacro-lumbalis, 
and  is  distributed  to  the  muscles  of  the  back,  its  terminal  filaments  reach- 
ing to  the  integument.  The  musculo-cutaneous  branch  passes  inwards, 
crossing  the  semispinalis  dorsi  to  the  spinous  processes  of  the  dorsal  verte- 
brae, giving  off  muscular  branches  in  its  course ;  it  then  pierces  the  apo- 
neurosis  of  origin  of  the  trapezius  and  latissimus  dorsi,  and  divides  into 
branches  which  are  inclined  outwards  beneath  the  integument  to  which 
they  are  distributed. 

The  dorsal  branch  of  \hefirst  dorsal  nerve  resembles  in  its  mode  of  dis- 
tribution the  dorsal  branches  of  the  last  cervical.  The  dorsal  branches  of 
the  last  four  dorsal  nerves  pass  obliquely  downwards  and  outwards  into 
the  substance  of  the  erector  spinse  in  the  situation  of  the  interspace  between 
the  sacro-lumbalis  and  longissimus  dorsi.  After  supplying  the  erector 
spiiia?  and  communicating  frtely  with  each  other  they  approach  the  surface 
along  the  outer  border  of  the  sacro-lumbalis,  where  they  pierce  the  apo- 
neuroses  of  the  transversalis,  internal  oblique,  serratus  posticus  inferior, 
and  latissimus  dorsi,  and  divide  into  internal  branches  which  supply  the 
integument  in  the  lumbar  region  upon  the  middle  line,  and  external  branches 
which  are  distributee*  to  the  integument  upon  the  side  of  the  lumbar  and 
in  the  gluteal  region. 

INTERCOSTAL  NERVES. — The  Intercostal  nerves  receive  one  or  two  fila- 
ments from  the  adjoining  ganglia  of  the  sympathetic,  and  pass  forwards  in 


SECOND    INTERCOSTO-HUMERAL    NERVE.  421 

the  intercostal  space  with  the  intercostal  vessels,  lying  below  the  veins  ana 
artery,  and  supplying  the  intercostal  muscles  in  their  course.  At  the  termi- 
nation of  the  intercostal  spaces  near  the  sternum,  the  nerves  pierce  the  in- 
tercostal and  pectoral  muscles,  and  incline  downwards  and  outwards  to  be 
distributed  to  the  integument  of  the  mamma  and  front  of  the  chest.  Those 
which  are  situated  between  the  false  ribs  pass  behind  the  costal  cartilages, 
and  between  the  transversalis  and  obliquus  internus  muscles,  and  supply  the 
rectus  and  the  integument  on  the  front  of  the  abdomen.  '  The  first  and  last 
dorsal  nerves  are  exceptions  to  this  distribution.  The  anterior  branch  of  the 
first  dorsal  nerve  divides  into  two  branches;  a  smaller, 'which  takes  its 
course  along  the  under  surface  of  the  first  rib  to  the  sternal  extremity  of 
the  first  intercostal  space  ;  and  a  larger,  which  crosses  obliquely  the  neck 
of  the  first  rib  to  join  the  brachial  plexus.  The  last  dorsal  nerve,  next  in 
size  to  the  first,  sends  a  branch  of  communication  to  the  first  lumbar  nerve, 
to  assist  in  forming  the  lumbar  plexus. 

The  Brandies  of  each  intercostal  nerve  are,  a  muscular  twig  to  t*je  in- 
tercostal and  neighbouring  muscles,  and  a  cutaneous  branch  which  is  given 
off  at  about  the  middle  of  the  arch  of  the  rib.  The  first  intercostal  nerve 
has  no  cutaneous  branch.  The  cutaneous  branches  of  the  second  and 
third  intercostal  nerves  are  named,  from  their  origin  and  distribution,  in- 
tercosto-humeral. 

The  FIRST  INTERCOSTO-HUMERAL  NERVE  is  of  large  size  ;  it  pierces  the 
external  intercostal  muscle  of  the  second  intercostal  space,  and  divides 
into  an  internal  and  an  external  branch.  The  internal  branch  is  distri- 
buted to  the  integument  of  the  inner  side  of  the  arm.  The  external  branch 
communicates  with  the  nerve  of  Wrisberg,  and  divides  into  filaments  which 
supply  the  integument  upon  the  inner  and  posterior  aspect  of  the  arm  as 
far  as  the  elbow.  This  nerve  sometimes  takes  the  place  of  the  nerve  of 
Wrisberg. 

The  SECOND  INTERCOSTO-HUMERAL  NERVE  is  much  smaller  than  the 
preceding ;  it  emerges  from  the  external  intercostal  muscle  of  the  third 
intercostal  space  between  the  serrations  of  the  serratus  magnus  muscle,  and 
divides  into  filaments  which  are  distributed  to  the  integument  of  the 
shoulder.  One  of  these  filaments  may  be  traced  inwards  to  the  integu- 
ment of  the  mamma.  The.  two  intercosto-humeral  nerves  not  unfrequently 
communicate  previously  to  their  distribution. 

The  cutaneous  branches  of  the  fourth  and  fifth  intercostal  nerve  send 
anterior  twigs  to  the  integument  of  the  mammary  gland  and  posterior  fila- 
ments to  the  scapular  region  of  the  back.  The  cutaneous  branches  of  the 
remaining  intercostal  nerves  reach  the  surface  between  the  serrations  of 
the  serratus  magnus  muscle  above  and  the  external  oblique  below,  and 
each  nerve  divides  into  an  anterior  and  a  posterior  branch ;  the  former 
being  distributed  to  the  integument  of  the  antero-lateral,  and  the  latter  to 
that  of  the  lateral  part  of  the  trunk. 

The  cutaneous  branch  of  the  last  dorsal  nerve  is  remarkable  for  its  size 
(n.  clunium  superior  anticus) ;  it  pierces  the  internal  and  external  oblique 
muscles,  crosses  the  anterior  part  of  the  crest  of  the  ilium,  and  is  distri- 
buted to  the  integument  of  the-gluteal  region  as  low  down  as  the  trochante* 
major. 

36 


422 


LUMBAR    PLEXUS. 


LUMBAR    NERVES. 

There  are  five  pairs  of  lumbar  nerves,  of  which  the  first  makes  its  ap- 
pearance between  the  first  and  second  lumbar  vertebrae,  and  the  last  be- 
tween the  fifth  lumbar  and  the  base  of  the  sacrum.  The  anterior  branches 
increase  in  size  from  above  downwards.  They  communicate  at  their  ori- 
gin with  the  lumbar  ganglia  of  the  sympathetic,  and  pass  obliquely  out- 
wards behind  the  psoas  magnus  or  between  its  fasciculi,  sending  twigs  to 
that  muscle  and  to  the  quadratus  lumborum.  In  this  situation  each  nerve 
divides  into  two  branches,  a  superior  branch  which  ascends  to  form  a  loop 
of  communication  with  the  nerve  above,  and  an  inferior  branch  which 
descends  to  join  in  like  manner  the  nerve  below,  the  communications  and 
anastomoses  which  are  thus  established  constituting  the  lumbar  plexus. 

The  posterior  branches  diminish  in  size  from  above  downwards ;  they 
pass  backwards  between  the  transverse  processes  of  the  corresponding 
vertebrae,  and  each  nerve  divides  into  an  internal  and  an  external  branch. 
The  internal  branch,  the  smaller  of  the  two,  passes  inwards  to  be  distri- 
buted to  the  multifidus  spinse  and  interspinales,  and  becoming  cutaneous 
supplies  the  integument  of  the  lumbar  region  on  the  middle  line.  The 
external  branches  communicate  with  each  other  by  several  loops,  and  after 

supplying  the    deeper   muscles, 

*V  189-*  pierce  the  sacro-lumbalis  to  reach 

the  integument  to  which  they  are 
distributed.  The  external  branches 
of  the  three  lower  lumbar  nerves 
(nervi  clunium  superiores  postici) 
descend  over  the  superior  part  of 
the  crest  of  the  ilium,  and  are  dis- 
tributed to  the  integument  of  the 
gluteal  region. 

LUMBAR    PLEXUS. 

The  Lumbar  plexus  is  formed 
by  the  communications  and  anas- 
tomoses which  take  place  between 
the  anterior  branches  of  the  five 
lumbar  nerves,  and  between  the 
latter  and  the  last  dorsal.  It  is 
narrow  above  and  increases  in 
breadth  inferiorly,  and  is  situated 
between  the  transverse  processes 
of  the  lumbar  vertebrae  and  the 
quadratus  lumborum  behind,  and 
the  psoas  magnus  muscle  in  front. 

*  A  view  of  the  lumbar  and  isehiatic  plexus  and  the  branches  of  the  former.  14. 
The  bodies  of  the  lumbar  vertebrae.  13.  The  psoas  magnus  muscle.  11.  The  iliacus 
internus  muscle.  15.  The  quadratus  lumborum  muscle.  16.  The  diaphragm.  12.  The 
three  broad  muscles  of  the  abdomen.  17.  The  sartorius.  1.  The  lumbar  plexus.  2. 
The  isehiatic  plexus.  3,  3.  Abdomino-crural  nerves.  4.  External  cutaneous  nerve 
(inguino-cutaneous).  5,  6,  7.  Cutaneous  branches  from  (8)  The  anterior  crural  nerve. 
9.  The  genito-crural  nerve  or  spermaticus  externus.  10,  10.  The  lower  termination  of 
«Ue  great  sympathetic. 


EXTERNAL  CUTANEOUS  NERVE.  423 

The  Branches  of  the  lumbar  plexus  are  the — 

Musculo-cutaneous,  Crural, 

External-cutaneous,  Obturator, 

Genito-crural,  Lumbo-sacral. 

The  MUSCULO-CUTANEOUS  NERVES,  two  in  number,  superior  and  infe- 
rior, proceed  from  the  first  lumbar  nerve.  The  superior  musculo-cutaneoua 
nerve  (ilio-scrotal,  ilio-hypogastricus),  passes  outwards  between  the  poste- 
rior fibres  of  the  psoas  magnus,  and  crossing  obliquely  the  quadratus 
lumborum  to  the  middle  of  the  crest  of  the  ilium,  pierces  the  transversalis 
muscle,  and  gives  off  a  cutaneous  branch.  It  then  winds  along  the  crest 
of  the  ilium  between  the  transversalis  and  internal  oblique,  and  divides 
into  two  branches,  abdominal  and  scrotal.  The  abdominal  branch  is  con- 
tinued forwards  parallel  with  the  last  intercostal  nerve  to  near  the  rectus 
muscle,  to  which  it  sends  branches  and  perforates  the  aponeuroses  of  the 
internal  and  external  oblique  to  be  distributed  to  the  integument  of  the 
mons  pubis  and  groin.  The  scrotal  branch,  opposite  the  anterior  superior 
spinous  process  of  the  ilium,  communicates  with  the  inferior  musculo- 
cutaneous  nerve,  and  passes  forward  to  the  external  abdominal  ring.  It 
then  pierces  the  cremaster  muscle  and  accompanies  the  spermatic  cord  in 
the  male,  and  the  round  ligament  in  the  female,  to  be  distributed  to  the 
integument  of  the  scrotum  or  external  labium.  The  inferior  musculo-cuta- 
neous  nerve  (ilio-inguinal)  also  arises  from  the  first  lumbar  nerve.  It  is 
much  smaller  than  the  preceding,  crosses  the  quadratus  lumborum  below 
it,  and  curves  along  the  crest  of  the  ilium  to  the  anterior  superior  spinous 
process,  resting  in  its  course  upon  the  iliac  fascia.  It  there  pierces  the 
transversalis  fascia  and  muscle,  communicates  with  the  scrotal  branch  of 
the  ilio-scrotal  nerve,  and  passes  along  the  spermatic  canal  with  the  sper- 
matic cord  to  be  similarly  distributed. 

The  EXTERNAL  CUTANEOUS  NERVE  (inguino-cutaneous)  proceeds  from 
the  second  lumbar  nerve.  It  pierces  the  posterior  fibres  of  the  psoas 
muscle  ;  and  crossing  the  iliacus  obliquely,  lying  upon  the  iliac  fascia,  to 
the  anterior  superior  spinous  process  of  the  ilium,  passes  into  the  thigh 
beneath  Poupart's  ligament.  It  then  pierces  the  fascia  lata  at  about  two 
inches  below  the  anterior  superior  spine  of  the  ilium,  and  divides  into  two 
branches,  anterior  and  posterior.  The  posterior  branch  crosses  the  tensor 
vaginae  femoris  muscle  to  the  outer  and  posterior  side  of  the  thigh,  and 
supplies  the  integument  in  that  region.  The  anterior  nerve  divides  into 
two  branches  which  are  distributed  to  the  integument  upon  the  outer  bor- 
der of  the  thigh,  and  to  the  articulation  of  the  knee. 

The  GENITO-CRURAL  proceeds  also  from  the  second  lumbar  nerve.  It 
traverses  the  psoas  magnus  from  behind  forwards,  and  runs  down  on  the. 
anterior  surface  of  that  muscle  and  beneath  its  fascia  to  near  Poupart's 
ligament,  where  it  divides  into  a  genital  and  a  crural  branch.  The  genital 
branch  (n.  spermaticus  seu  pudendus  externus)  crosses  the  external  iliac 
artery  to  the  internal  abdominal  ring  and  descends  along  the  spermatic 
canal,  lying  behind  the  cord  to  the  scrotum,  where  it  divides  into  branches 
which  supply  the  spermatic  cord  and  cremaster  in  the  male,  and  the  round 
ligament  and  external  labium  in  the  female.  At  the  internal  abdominal 
ring  this  nerve  sends  off  a  branch  which  after  supplying  the  lower  border 


424 


CRURAL    NERVE. 


Fig.  190.* 


of  the  internal  oblique  and  transversalis,  is  distributed  to  the  integument 
of  the  groin.  The  crural  branch  (lumbo-inguinalis),  the  most  external  of 
the  two,  descends  along  the  outer  border  of  the  external  iliac  artery,  and, 
crossing  the  origin  of  the  circumflex  ilii  artery,  enters  the  sheath  of  the 
femoral  vessels  in  front  of  the  femoral  artery.  It  pierces  the  sheath  below 
Poupart's  ligament,  and  is  distributed  to  the  integument  of  the  anterior 
aspect  of  the  thigh  as  far  as  its  middle.  This  nerve  is  often  very  small, 
and  sometimes  communicates  with  one  of  the  cutaneous  branches  of  the 
crural  nerve. 

The  CRURAL,  or  FEMORAL  NERVE,  is  the  largest 
of  the  divisions  of  the  lumbar  plexus ;  it  is  formed 
by  the  union  of  branches  from  the  second,  third, 
and  fourth  lumbar  nerves,  and,  emerging  from 
beneath  the  psoas  muscle,  passes  downwards  in 
the  groove  between  it  and  the  iliacus,  and  beneath 
Poupart's  ligament  into  the  thigh,  where  it  spreads 
out  and  divides  into  numerous  branches.  At 
Poupart's  ligament  it  is  separated  from  the  femo- 
ral artery  by  the  breadth  of  the  psoas  muscle, 
which  at  this  point  is  scarcely  more  than  half  an 
inch  in  diameter,  and  by  the  iliac  fascia,  beneath 
which  it  lies. 

Branches. — While  situated  within  the  pelvis  the 
crural  nerve  gives  off  several  muscular  branches 
to  the  iliacus,  and  one  to  the  psoas.  On  emerg- 
ing from  beneath  Poupart's  ligament  the  nerve 
becomes  flattened  and  divides  into  numerous 
branches,  which  may  be  arranged  into, — 

Cutaneous, 

Muscular, 

Branch  to  the  femoral  sheath, 

Short  saphenous  nerve, 

Long  saphenous  nerve. 

The  Cutaneous  nerves  (middle  cutaneous)  twc 
in  number,  proceed  from  the  anterior  part  of  the 
crural,  and  after  perforating  the  sartorius  muscle 
to  which  they  give  filaments,  pierce  the  fascia  lata 
and  are  distributed  to  the  integument  of  the  mid- 
dle and  lower  part  of  the  thigh  and  of  the  knee. 
The  most  external  of  these  nerves  perforates  the 
upper  part  of  the  sartorius,  communicates  with  the 

crural  branch  of  the  genito-crural,  divides  into  two  branches  at  about  the 
middle  of  the  thigh,  and  gives  off  numerous  filaments  to  the  anterior  and 
outer  aspect  of  the  limb  as  far  as  the  patella.  The  internal  nerve  perfo- 
rates the  muscle  at  about  its  middle,  pierces  the  fascia  lata  at  the  lower 
third  of  the  thigh,  descends  to  the  inner  condyle,  and  curves  forward  to 
the  front  of  the  knee,  supplying  the  integument  by  many  filaments.  Be- 
sides these  another  cutaneous  branch  derived  from  the  muscular  branch 

*  A  view  of  the  anterior  crural  nerve  and  branches.  1.  Place  of  emergence  of  the 
nerve  under  Pnnpart's  ligament.  2.  Division  of  the  nerve  into  branches.  3.  Femoral 
mitery  4.  Femoral  vein.  5.  Branches  of  obturator  nerve.  6.  Nervus  saphenus 


SAPHENOUS    [VERVES.  425 

to  the  vastus  exteraus  is  found  on  the  outer  side  of  the  lower  third  of  the 
thigh. 

The  Muscular  branches  are  several  large  twigs  which  are  distributed  to 
the  muscles  of  the  anterior  aspect  of  the  thigh.  One  of  these  is  sent  to 
the  rectus ;  one  to  the  vastus  externus,  which  gives  off  a  cutaneous  twig 
to  the  outer  aspect  of  the  thigh ;  one  to  the  crurasus,  and  one  lar^e  and 
long  branch  to  the  vastus  internus.  From  the  two  latter,  filaments  are 
distributed  to  the  periosteum  and  knee  joint.  The  sartorius  receives  its 
supply  of  nerves  from  the  cutaneous  nerves  by  which  it  is  perforated. 

The  Branch  to  tlie  femoral  sheath  is  a  small  nerve  which  passes  inwards 
to  the  sheath  of  the  femoral  vessels  at  the  upper  part  of  the  thigh,  and  di- 
vides into  several  filaments  which  surround  the  femoral  and  profunda  ves- 
sels. Two  of  these  filaments,  one  from  the  front,  and  the  other  from  the 
posterior  part  of  the  sheath,  unite  to  form  a  small  nerve  which  escapes 
from  the  saphenous  opening  and  passes  downwards  with  the  saphenous 
vein.  Other  filaments  are  distributed  to  the  adductor  muscles,  and  com- 
municate with  the  long  saphenous  nerve. 

The  Short  saphenous  nerve  (n.  cutaneus  internus)  inclines  inwards  to 
the  sheath  of  the  femoral  vessels,  and  divides  into  a  superficial  and  a  deep 
branch.  The  superficial  branch  passes  downwards  along  the  inner  border 
of  the  sartorius  muscle  to  the  lower  third  of  the  thigh ;  it  then  pierces  the 
fascia  lata,  joins  the  internal  saphenous  vein,  and  accompanies  that  vessel 
to  the  knee  joint,  where  it  terminates  by  communicating  with  the  long 
saphenous  nerve.  The  deep  branch  descends  on  the  outer  side  of  the 
sheath  of  the  femoral  vessels,  and  crosses  the  sheath  at  its  lower  part  to  a 
point  opposite  the  termination  of  the  femoral  artery,  where  it  divides  into 
several  filaments  which  constitute  a  plexus  by  their  communication  with 
other  nerves.  One  of  these  filaments  communicates  \vith  the  descending 
branch  of  the  obturator  nerve,  another  with  the  long  saphenous  nerve,  and 
two  or  three  are  distributed  to  the  integument  upon  the  internal  and  pos- 
terior aspect  of  the  thigh. 

The  Long  saphenous  nerve  (n.  cutaneus  internus  longus)  inclines  in- 
wards to  the  sheath  of  the  femoral  vessels,  and  entering  the  sheath  accom- 
panies the  femoral  artery  to  the  aponeurotic  canal  formed  by  the  adductor 
longus  and  vastus  internus  muscles.  It  then  quits  the  artery,  and,  pass- 
ing between  the  tendons  of  the  sartorius  and  gracilis,  descends  along  the 
inner  side  of  the  leg  with  the  internal  saphenous  vein,  crosses  in  front  of 
the  inner  ankle,  and  is  distributed  to  the  integument  on  the  inner  side  of 
the  foot  as  far  as  the  great  toe. 

The  internal  saphenous  nerve  receives  from  the  obturator  nerve  two 
branches  of  communication,  one  near  its  upper  part,  which  passes  through 
the  angle  of  division  of  the  femoral  artery,  and  the  other  at  the  internal 
condyle.  The  branches  which  it  gives  off  in  its  course  are,  a  femoral 
cutaneous  branch,  at  about  the  middle  of  the  thigh,  distributed  to  the  in- 
tegument of  the  inner  and  posterior  aspect  of  the  limb,  and  communicat- 
ing with  other  cutaneous  filaments  from  the  saphenous  below  the  knee  ;  a 
tibial  cutaneous  branch  proceeding  from  the  nerve  a  little  above  the  inteiiial 
condyle,  passing  between  the  sartorius  and  gracilis  and  descending  the 
inner  aspect  of  the  leg  to  the  ankle  ;  an  articular  branch  of  small  size,  pro  • 
ceeding  from  the  nerve  while  in  the  aponeurotic  canal  of  the  femoral 
artery,  and  passing  directly  to  the  knee  joint  to  supply  the  synovial  mem- 
brane ;  an  anterior  cr.taneous  branch  proceeding  from  the  saphenous  at  the 
36* 


426  SACRAL    NERVES. 

inner  condyle,  perforating  the  sartorius,  and  dividing  into  a  number  of 
filaments  which  supply  the  integument  over  the  patella  and  around  the 
joint,  and  the  integument  of  the  front  and  outer  aspect  of  the  leg  as  far  as 
the  ankle ;  lastly,  cutaneous  filaments  below  the  knee  to  supply  the  inner 
side  and  front  of  the  leg  and  foot,  and  articular  branches  to  the  ankle  joint. 

The  OBTURATOR  NERVE  is  formed  by  a  branch  from  the  third,  and  an- 
other from  the  fourth  lumbar  nerve.  It  passes  downwards  among  the 
fibres  of  the  psoas  muscle,  through  the  angle  of  bifurcation  of  the  common 
iliac  vessels,  and  along  the  inner  border  of  the  brim  of  the  pelvis,  to  the 
obturator  foramen,  where  it  joins  the  obturator  artery.  Having  escaped 
from  the  pelvis  it  gives  off  two  small  twigs  to  the  obturator  externus  muscle 
and  divides  into  four  branches,  three  anterior,  which  pass  in  front  of  the 
adductor  brevis,  supplying  that  muscle,  the  pectineus,  the  adductor  longus, 
and  the  gracilis ;  and  a  posterior  branch  which  passes  downwards  behind 
the  adductor  brevis,  and  ramifies  in  the  adductor  magnus. 

From  the  branch  which  supplies  the  adductor  brevis,  a  communicating 
filament  passes  outwards  through  the  angle  of  bifurcation  of  the  femoral 
vessels  to  unite  with  the  long  saphenous  nerve.  From  the  branch  to  the 
adductor  longus  a  long  cutaneous  nerve  proceeds,  which  issues  from  be- 
neath the  inferior  border  of  that  muscle,  sends  filaments  of  communication 
to  the  plexus  of  the  short  saphenous  nerve,  and  descends  to  the  inner  side 
of  the  knee,  where  it  pierces  the  fascia  and  communicates  with  the  long 
saphenous  nerve.  It  is  distributed  to  the  integument  upon  the  inner  side 
of  the  leg.  From  the  posterior  branch  an  articular  branch  is  given  off 
which  pierces  the  adductor  magnus  muscle,  accompanies  the  popliteal 
artery,  and  is  distributed  to  the  synovial  membrane  of  the  knee  joint  on 
its  posterior  aspect. 

The  LUMBO-SACRAL  NERVE. — /The  anterior  division  of  the  fifth  lumbar 
nerve,  conjoined  with  a  branch  from  the  fourth,  constitutes  the  lumbo- 
sacral  nerve,  which  descends  over  the  base  of  the  sacrum  into  the  pelvis, 
and  assists  in  forming  the  sacral  plexus. 

SACRAL    NERVES. 

There  are  six  pairs  of  sacral  nerves ;  the  first  escape  from  the  vertebral 
canal  through  the  first  sacral  foramina,  and  the  two  last  between  the  sacrum 
and  coccyx.  The  posterior  sacral  nerves  are  very  small,  and  diminish  in 
size  from  above  downwards ;  they  communicate  with  each  other  immedi- 
ately after  their  escape  from  the  posterior  sacral  foramina,  and  divide  into 
external  and  internal  branches.  The  external  branches  pierce  the  gluteus 
maximus,  to  which  they  give  filaments,  and  are  distributed  to  the  integu- 
ment of  the  posterior  part  of  the  gluteal  region  (n.  cutanei  clunium  poste- 
riores).  The  internal  supply  the  integument  over  the  sacrum  and  coccyx. 

The  anterior  sacral  nerves  diminish  in  size  from  above  downwards  ;  the 
first  is  large  and  unites  with  the  lumbo-sacral  nerve ;  the  second,  of  equal 
size,  unites  with  the  preceding ;  the  third,  which  is  scarcely  one-fourth  so 
large  as  the  second,  also  joins  with  the  preceding  nerves  in  the  formation 
of  the  sacral  plexus.  The  fourth  anterior  sacral  nerve  is  about  one-third 
the  size  of  the  preceding  sacral  nerve ;  it  divides  into  several  branches, 
one  of  which  is  sent  to  the  sacral  plexus,  a  second  to  join  the  fifth  sacral 


Fig.  191  .* 


SACRAL    PLEXUS.  427 

nerve,  a  third  to  the  viscera  of  the  pelvis  commu- 
nicating with  the  hypogastric  plexus,  and  a  fourth 
to  the  coccygeus  muscle,  and  to  the  integument 
around  the  anus.  The  fifth  anterior  sacral  nerve 
presents  about  half  the  size  of  the  fourth ;  it  di- 
vides into  two  branches,  one  of  which  communi- 
cates with  the  fourth,  the  other  with  the  sixth. 
The  sixth  sacral  nerve  (coccygeal)  is  exceedingly 
small ;  it  gives  off  an  ascending  filament  which  is 
continuous  with  the  communicating  branch  of  the 
fifth;  and  a  descending  filament  which  passes 
downwards  by  the  side  of  the  coccyx  and  traverses 
the  fibres  of  the  great  sacro-ischiatic  ligament  to 
be  distributed  to  the  gluteus  maximus  and  to  the 
integument.  All  the  anterior  sacral  nerves  receive 
branches  from  the  sacral  ganglia  of  the  sympathetic 
at  their  emergence  from  the  sacral  foramina. 

SACRAL    PLEXUS. 

The  Sacral  plexus  is  formed  by  the  lumbo-sacral 
and  by  the  anterior  branches  of  the  four  upper 
sacral  nerves.  The  plexus  is  triangular  in  form, 

the  base  corresponding  with  the  whole  length  of  the  sacrum,  and  the  apex 
with  the  lower  part  of  the  great  ischiatic  foramen.  It  is  in  relation  behind 
with  the  pyriformis  muscle,  and  in  front  with  the  pelvic  fascia,  which  latter 
separates  it  from  the  branches  of  the  internal  iliac  artery,  and  from  the 
viscera  of  the  pelvis. 

The  Branches  of  the  sacral  plexus  are  divisible  into  the  internal  and  the 
external ;  they  may  be  thus  arranged : — 


Internal. 
Visceral, 
Muscular. 


External. 


Muscular, 
Gluteal, 
Internal  pudic, 
Lesser  ischiatic, 
Greater  ischiatic. 

The  Visceral  nerves  are  three  or  four  large  branches  which  are  derived 
from  the  fourth  and  fifth  sacral  nerves :  they  ascend  upon  the  side  of  the 
rectum  and  bladder ;  in  the  female  upon  the  side  of  the  rectum,  the  va- 
gina and  the  bladder;  and  interlace  with  the  branches  of  the  hypogastric 
plexus,  sending  in  their  course  numerous  filaments  to  those  viscera. 

The  Muscular  brandies  given  off  within  the  pelvis  are  one  or  two  twigs 
to  the  levator  ani ;  an  obturator  branch ;  which  curves  around  the  spine 
of  the  ischium  to  reach  the  internal  surface  of  the  obturator  internus  mus- 
cle ;  a  coccygeal  branch ;  and  an  heemorrhoidal  nerve  which  passes 
through  the  two  ischiatic  openings  and  descends  to  the  termination  of  the 
rectum  to  supply  the  sphincter  and  the  integument. 

*  A  view  of  the  branches  of  the  ischiatic  plexus  to  the  hip  and  back  of  the  thigh.  1, 
1.  Posterior  sacral  nerves.  2.  Nervi  glutei.  3.  The  internat  pudic  nerve  (nervus  puden- 
dalis  longus  superior).  4.  The  lesser  ischiatic  nerve,  giving  off  the  perineal  cutaneous 
(pudendalis  longus  inferior),  and  5.  The  ramus  femoralis  cutaneus  posterior.  The  to- 
furence  to  the  great  ischiatic  has  been  omitted.  It  is  seen  to  the  right  of  3. 


428  LESSER    ISCHIATIC    NERVE. 

The  Muscular  branches  supplied  by  the  sacral  plexus  externally  to  the 
pelvis  are,  a  branch  to  the  pyramidalis ;  a  branch  to  the  gemellus  supe- 
rior ;  and  a  branch  of  moderate  size  which  descends  between  the  gemelli 
muscles  and  the  ischium,  and  is  distributed  to  the  gemellus  inferior,  the 
quadratus  femoris,  and  the  capsule  of  the  hip  joint. 

The  GLUTEAL  NERVE  (superior  gluteal)  is  a  branch  of  the  lumbo-sacral ; 
it  passes  out  of  the  pelvis  with  the  gluteal  artery,  through  the  great  sacro- 
ischiatic  foramen,  and  divides  into  a  superior  and  an  inferior  branch. 
The  superior  branch  follows  the  direction  of  the  superior  curved  line  of 
the  ilium,  accompanying  the  deep  superior  branch  of  the  gluteal  artery, 
and  sending  filaments  to  the  gluteus  medius  and  minimus.  The  inferior 
passes  obliquely  downwards  and  forwards  between  the  gluteus  medius 
and  minimus,  distributing  numerous  filaments  to  both,  and  terminates  in 
the  tensor  vaginae  femoris  muscle. 

The  INTERNAL  Pumc  NERVE  arises  from  the  lower  part  of  the  sacral 
plexus,  passes  out  of  the  pelvis  through  the  great  sacro-ischiatic  foramen 
below  the  pyriformis  muscle,  and  takes  the  course  of  the  internal  pudic 
artery.  While  situated  beneath  the  obturator  fascia  it  lies  below  that 
vessel  and  divides  into  a  superior  and  an  inferior  branch. 

The  Superior  nerve  (dorsalis  penis)  ascends  upon  the  posterior  surface 
of  the  ramus  of  the  ischium,  pierces  the  deep  perineal  fascia  and  accom- 
panies the  arteria  dorsalis  penis  to  the  glans,  to  which  it  is  distributed. 
At  the  root  of  the  penis  this  nerve  gives  off  a  cutaneous  branch  which 
runs  along  the  side  of  the  organ,  gives  filaments  to  the  corpus  cavernosum, 
and  with  its  fellow  of  the  opposite  side  supplies  the  integument  of  the 
upper  two-thirds  of  the  penis  and  prepuce. 

The  Inferior  or  perineal  nerve  pursues  the  course  of  the  internal  pudic 
artery  in  the  perineum  and  sends  off  three  principal  branches,  an  external 
perineal  branch,  which  ascends  upon  the  outer  side  of  the  crus  penis,  and 
supplies  the  scrotum;  a  superficial  perineal  branch,  which  accompanies 
the  artery  of  that  name  and  distributes  filaments  to  the  scrotum,  to  the 
integument  of  the  under  part  of  the  penis  and  to  the  prepuce ;  and,  thirdly, 
the  bulbo-urethral  branch,  which  sends  twigs  to  the  sphincter  ani,  traris- 
versus  perinei,  and  accelerator  urines,  and  terminates  by  ramifying  in  the 
corpus  spongiosum. 

In  the  female  the  internal  pudic  nerve  is  distributed  to  the  parts  analo- 
gous to  those  of  the  male.  The  superior  branch  supplies  the  clitoris ;  and 
the  inferior  the  vulva  and  parts  in  the  perineum. 

The  LESSER  ISCHIATIC  NERVE  passes  out  of  the  pelvis  through  the  great 
sacro-ischiatic  foramen  below  the  pyriformis  muscle,  and  divides  into 
muscular  and  cutaneous  branches.  The  muscular  branches,  inferior  glu- 
teal, are  distributed  to  the  gluteus  maximus ;  some  ascending  in  the  sub- 
stance of  that  muscle  to  its  upper  border,  and  others  descending.  The 
cutaneous  branches  are,  several  ascending  filaments  to  the  integument 
over  the  gluteus  maximus  (n.  cutanei  clunium  inferiores),  perineal  cuta- 
neous, and  middle  posterior  cutaneous. 

The  Perineal  cutaneous  nerve  (pudendalis  longus  inferior),  curves  around 
the  tuberosity  of  the  ischium  and  ascends  in  a  direction  parallel  to  the 
ramus  of  the  ischium  and  os  pubis  to  the  scrotum,  where  it  communicates 


POPLITEAL    NERVE.  429 

with  the  superficial  perineal  nerve,  and  divides  into  an  internal  and  an 
external  branch.  The  internal  branch  passes  down  upon  the  inner  side 
of  the  testis  to  the  scrotum  ;  the  external  branch  to  its  outer  side,  and  both 
terminate  in  the  integument  of  the  under  border  of  the  penis. 

The  Middle  posterior  cutaneous  nerve  crosses  the  tuberosity  of  the  is- 
chium  and  pierces  the  deep  fascia  at  the  lower  border  of  the  gluteus  max- 
imus.  It  then  passes  downwards  along  the  middle  of  the  posterior  aspect 
of  the  thigh  and  of  the  popliteal  region,  and  is  distributed  to  the  integu- 
ment as  far  as  the  mMdle  of  the  calf  of  the  leg.  In  its  course  the  nerve 
gives  off  several  cutaneous  branches  to  the  integument  of  the  inner  and 
outer  side  of  the  thigh,  and  in  the  popliteal  region  a  communicating  branch 
which  pierces  the  fascia  of  the  leg  and  unites  with  the  external  saphenous 
nerve. 

The  GREAT  ISCHIATIC  NERVE  is  the  largest  nervous  cord  in  the  body ; 
it  is  formed  by  the  sacral  plexus,  or  rather  is  a  prolongation  of  the  plexus, 
and  at  its  exit  from  the  great  sacro-ischiatic  foramen  beneath  the  pyriformis 
muscle  measures  three  quarters  of  an  inch  in  breadth.  It  descends  through 
the  middle  of  the  space  between  the  trochanter  major  and  tuberosity  of  the 
ischium,  and  along  the  posterior  part  of  the  thigh  to  about  its  lower  third, 
where  it  divides  into  two  large  terminal  branches,  popliteal  and  peroneal. 
This  division  sometimes  takes  place  at  the  plexus,  and  the  two  nerves 
descend  together  side  by  side ;  occasionally  they  are  separated  at  their 
commencement  by  a  part  or  the  whole  of  the  pyriformis  muscle.  The 
nerve  in  its  course  down  the  thigh  rests  upon  the  gemellus  superior,  ten- 
don of  the  obturator  internus,  gemellus  inferior,  quadratus  femoi  is,  and 
adductor  magnus  muscle,  and  is  covered  in  by  the  gluteus  maximus, 
biceps,  semi-tendinosus,  and  semi-membranosus. 

The  Branches  of  the  great  ischiatic  nerve,  previously  to  its  division,  are 
muscular  and  articular.  The  muscular  branches  are  given  off  from  the 
upper  part  of  the  nerve,  and  supply  both  heads  of  the  biceps,  the  semi- 
tendinosus,  semi-membranosus,  and  adductor  magnus.  The  articular 
branch  descends  to  the  upper  part  of  the  external  condyle  of  the  femur, 
and  divides  into  filaments  which  are  distributed  to  the  fibrous  capsule  and 
to  the  synovial  membrane  of  the  knee  joint. 

The  POPLITEAL  NERVE  passes  through  the  middle  of  the  popliteal  space, 
from  the  division  of  the  great  ischiatic  nerve  to  the  lower  border  of  the 
popliteus  muscle,  accompanies  the  artery  beneath  the  arch  of  the  soleus, 
and  becomes  the  posterior  tibial  nerve.  It  is  superficial  in  the  whole  of 
its  course,  and  lies  externally  to  the  vein  and  artery. 

The  Branches  of  the  popliteal  nerve  are  muscular  or  sural,  and  articular, 
and  a  cutaneous  branch,  the  communicans  poplitei. 

The  Muscular  branches,  of  considerable  size,  and  four  or  five  in  num- 
ber, are  distributed  to  the  two  heads  of  the  gastrocnemius,  to  the  soleus, 
plantaris,  and  popliteus. 

The  Articular  nerve  pierces  the  ligamentum  posticum  Winslowii,  and 
supplies  the  interior  of  the  knee  joint.  It  usually  sends  a  twig  to  the 
popliteus  muscle. 

The    Communicans  poplitei  (communicans  tibialis)  is  a  large   nerve 
which  arises  from  the  popliteal  at  about  the  middle  of  its  course,  and  de 
scends  between  the  two  heads  of  the  gastrocnemius,  and  along  the  groove 


430  POSTERIOR   TIBIAL    NERVE. 

formed  by  the  two  bellies  of  that  muscle ;  at  a  variable  distance  below 
the  articulation  of  the  knee  it  receives  a  large  branch,  the  communicans 
peronei,  from  the  peroneal  nerve,  and  the  two  together  constitute  the  ex- 
ternal saphenous  nerve. 

The  External  saphenous  nerve  pierces  the  deep  fascia  below  the  fleshy 
part  of  the  gastrocnemius  muscle,  and  continues  its  course  down  the  leg, 
lying  along  the  outer  border  of  the  ten  do  Achillis  and  by  the  side  of  the 
external  saphenous  vein,  which  it  accompanies  to  the  foot.  At  the  lower 
part  of  the  leg  it  winds  around  the  outer  malleolus,  and  is  distributed  to 
the  outer  side  of  the  foot  and  little  toe,  communicating  with  the  external 
peroneal  cutaneous  nerve,  and  sending  numerous  filaments  to  the  integu 
ment  of  the  heel  and  sole  of  the  foot. 


Fig.  192* 


Fig.  193.f 


fhe  POSTERIOR  TIBIAL  NERVE  is  continued  along  the  posterior  aspect 
of  the  leg  from  the  lower  border  of  the  popliteus  muscle  to  the  posterior 
part  of  the  inner  ankle,  where  it  divides  into  the  internal  and  external 
plantar  nerve.  In  the  upper  part  of  its  course  it  lies  to  the  outer  side  of 

*  A  view  °f  some  of  the  branches  of  the  popliteal  nerve.  1.  The  popliteal  nerve. 
The  terminations  of  the  ramus  femoralis  cutaneus  posterior.  4,  5.  The  saphenous 
nerve.  6,  6.  The  external  saphenous  or  communicans  tibia}. 

t  A  view  of  the  posterior  tibial  nerve  in  the  back  of  the  leg.  1  and  2,  indicate  1U 
course,  the  upper  part  of  the  peroneal  nerve  being  seen  to  the  right. 


Fig.  194.f 


PERONEAL    NERVE.  431 

the  posterior  tibial  artery;  it  then  becomes  placed  superficially  to  that 
vessel,  and  at  the  ankle  is  again  situated  to  its  outer  side ;  in  the  lower 
third  of  the  leg  it  lies  parallel  with  the  inner  border  of  the  tendo 
Achillis. 

The  Branches  of  the  posterior  tibial  nerve  are  three  or  four  muscular 
twigs  to  the  deep  muscles  of  the  posterior  aspect  of  the  leg,  the  branch  to 
the  flexor  longus  pollicis  accompanies  the  fibular  artery ;  one  or  t\yo  fila 
ments  which  entwine  around  the  artery  and  then  terminate  in  the  integu- 
ment ;*  and  two  or  three  plantar  cutaneous  branches  which  pass  down- 
wards upon  the  inner  side  of  the  os  calcis,  and  are  distributed  to  the 
integument  of  the  heel. 

The  INTERNAL  PLANTAR  NERVE,  larger  than  the  external,  crosses  the 
posterior  tibial  vessels  to  enter  the  sole  of  the  foot,  where  it  lies  in  the 
interspace  between  the  abductor  pollicis  and  flexor 
brevis  digitorum ;  it  then  enters  the  sheath  of  the 
latter  muscle,  and  divides  opposite  the  bases  of  the 
metatarsal  bones  into  three  digital  branches ;  one  to 
supply  the  adjoining  sides  of  the  great  and  second 
toe ;  the  second  the  adjoining  sides  of  the  second 
and  third  toe  ;  and  the  third  the  corresponding 
sides  of  the  third  and  fourth  toes.  This  distribution 
is  precisely  similar  to  that  of  the  digital  branches  of 
the  median  nerve. 

In  its  course  the  internal  plantar  nerve  gives  off 
cutaneous  branches  to  the  integument  of  the  inner 
side  and  sole  of  the  foot ;  muscular  branches  to  the 
muscles  forming  the  inner  and  middle  group  of  the 
sole ;  a  digital  branch  to  the  inner  border  of  the 
great  toe ;  and  articular  branches  to  the  articula- 
tions of  the  tarsal  and  metatarsal  bones. 

The  EXTERNAL  PLANTAR  NERVE,  the  smaller  of 
the  two,  follows  the  course  of  the  external  plantar 
artery  to  the  outer  border  of  the  musculus  accesso- 
rius,  beneath  which  it  sends  several  large  muscular 
branches  to  supply  the  adductor  pollicis  and  the 
articulations  of  the  tarsal  and  metatarsal  bones.  It  then  gives  branches  to 
the  integument  of  the  outer  border  and  sole  of  the  foot,  and  sends  forward 
two  digital  branches  to  supply  the  little  toe  and  one  half  the  next. 

The  PERONEAL  NERVE  is  one-half  smaller  than  the  popliteal ;  it  passes 
downwards  by  the  side  of  the  tendon  of  the  biceps,  crossing  the  inner 
head  of  the  gastrocnemius  and  the  origin  of  the  soleus,  to  the  neck  of  the 

*  It  is  extremely  interesting,  in  a  physiological  point  of  view,  to  observe  the  mode  of 
distribution  of  these  filaments.  I  have  traced  them  in  relation  with  several,  and  I  have 
no  doubt  that  they  exist  in  connexion  with  all  the  superficial  arteries.  They  seem,  to  be 
the  direct  monitors  to  the  artery  of  the  presence  or  approach  of  danger. 

•j-  A  view  of  the  termination  of  the  posterior  tibial  nerve  in  the  sole  of  the  foot.  1 .  In- 
tide  of  the  foot.  2.  Outer  side.  3.  Heel.  4.  Internal  plantar  nerve.  5.  External  plantar 
nerve.  6.  Branch  to  flexor  brevis.  7.  Branch  to  outside  of  little  toe.  8.  Branch  to  space 
between  4th  and  5th  toes.  9,  9,  9.  Digital  branches  to  remaining  spaces.  10.  Brarioh 
to  internal  side  of  great  ».oe. 


432 


MUSCULO-CUTANEOUS    NERVE. 


Fig.  195.* 


fibula,  where  it  pierces  the  origin  of  the  peroneus  longus  muscle,  and 
divides  into  two  branches,  the  anterior  tibial  and  musculo-cutaneous. 

The  Branches  of  the  peroneal  nerve  previously  to  its  division  are,  the 
communicans  peronei,  cutaneous,  articular,  and  muscular.  The  commu- 
nicans  peronei^  much  smaller  than  the-  communicans  poplitei,  crosses  the 
external  head  of  the  gastrocnemius  to  the  middle  of  the  leg.  It  there 
sends  a  large  branch  to  join  the  communicans  poplitei  and  constitute  the 
external  saphenous  nerve,  and  descends  very  much  reduced  in  size  with 
the  external  saphenous  vein  to  the  side  of  the  external  ankle,  to  which  and 
to  the  integument  of  the  heel  it  distributes  filaments.  The  cutaneous  branch 
passes  down  the  outer  side  of  the  leg,  supplying  the  integument.  The 
articular  is  a  small  branch  distributed  to  the  knee  joint.  The  muscular 
branches  are  twigs  to  the  short  head  of  the  biceps,  peroneus  longus,  and 
tibialis  anticus. 

The  ANTERIOR  TIBIAL  NERVE  commences  at  the 
bifurcation  of  the  peroneal,  upon  the  head  of  the  fibula, 
and  passes  beneath  the  upper  part  of  the  extensor  longus 
digitorum,  to  reach  the  outer  side  of  the  anterior  tibial 
artery,  just  as  that  vessel  has  emerged  through  the  open- 
ing in  the  interosseous  membrane.  It  descends  the  an- 
terior aspect  of  the  leg  with  the  artery ;  lying  at  first  to 
its  outer  side,  and  then  in  front  of  it,  and  near  the  ankle 
becomes  again  placed  to  its  outer  side.  Reaching  the 
ankle,  it  passes  beneath  the  annular  ligament ;  accom- 
panies the  dorsalis  pedis  artery,  supplies  the  adjoining 
sides  of  the  great  and  second  toes,  and  communicates 
w:ith  the  internal  peroneal  cutaneous  nerve. 

The  Branches  given  off  by  the  anterior  tibial  nerve 
are,  muscular  to  the  muscles  in  its  course,  and  on  the 
foot  a  tarsal  branch  which  passes  beneath  the  extensor 
brevis  digitorum,  and  distributes  filaments  to  the  inter- 
ossei  muscles  and  to  the  articulations  of  the  tarsus  and 
metatarsus. 

The  MUSCULO-CUTANEOUS  NERVE  passes  downwards 
in  the  direction  of  the  fibula,  in  the  substance  of  the 
peroneus  longus ;  it  then  passes  forwards  to  get  between 
the  peroneus  longus  and  brevis,  and  at  the  lower  third 
of  the  leg  pierces  the  deep  fascia,  and  divides  into  two 
peroneal  cutaneous  branches.  In  its  course  it  gives  off 
several  branches  to  the  peronei  muscles. 

The  Peroneal  cutaneous  nerves  pass  in  front  of  the 
ankle  joint,  and  are  distributed  to  the  integument  of 
the  foot  and  toes ;  the  external  supplying  three  toes 
and  a  half,  and  the  internal  one  and  a  half.  They 
communicate  with  the  saphenous  and  anterior  tibial 

nerves.    The  external  saphenous  nerve  frequently  supplies  the  fifth  toe  and 

the  adjoining  side  of  the  fourth. 

•  A  view  of  the  anterior  tibial  nerve.     1.  The  peroneal  nerve.     2,  3.  The  anterior 
tibial  nerve  accompanying  the  artery  of  the  same  name. 


CRAiNIAL    GANGLIA.  433 


SYMPATHETIC    NERVES. 

The  Sympathetic  system  consists  of  a  series  of  ganglia,  extending  along 
each  side  of  the  vertebral  column  from  the  head  to  the  coccyx,  communi- 
cating with  all  the  other  nerves  of  the  body,  and  distributing  branches  to 
all  the  internal  organs  and  viscera. 

It  communicates  with  the  other  nerves  immediately  at  their  exit  from 
the  cranium  and  vertebral  canal.  The  fourth  and  sixth  nerves,  however, 
form  an  exception  to  this  rule ;  for  with  these  it  unites  in  the  cavernous 
sinus ;  and  with  the  olfactory,  optic,  and  auditory,  at  their  ultimate  ex- 
pansions. 

The  branches  of  distribution  accompany  the  arteries  which  supply  the 
different  organs,  and  form  communications  around  them,  which  are  called 
plexuses,  and  take  the  name  of  the  artery  with  which  they  are  associated : 
thus  we  have  the  mesenteric  plexus,  hepatic  plexus,  splenic  plexus,  &c. 
All  the  internal  organs  of  the  head,  neck,  and  trunk  are  supplied  with 
branches  from  the  sympathetic,  and  some  of  them  exclusively ;  hence  it  is 
considered  a  nerve  of  organic  life. 

It  is  called  the  ganglionic  nerve  from  the  circumstance  of  being  formed 
by  a  number  of  ganglia;  and  from  the  constant  disposition  which  it 
evinces  in  its  distribution,  to  communicate  and  form  small  knots  or 
ganglia. 

There  are  five  sympathetic  ganglia  in  the  head ;  viz.  the  ganglion  of 
Ribes;  the  ciliary  or  lenticular;  the  spheno-palatine,  or  Meckel's;  the 
otic,  or  Arnold's;  and  the  submaxillary :  three  in  the  neck;  superior, 
middle,  and  inferior :  twelve  in  the  dorsal  region ;  four  in  the  lumbar  re- 
gion ;  and  four  or  five  in  the  sacral  region. 

Each  ganglion  may  be  considered  as  a  distinct  centre  giving  off  branches 
in  four  different  directions,  viz.,  supenor  or  ascending,  to  communicate 
with  the  ganglion  above ;  inferior  or  descending,  to  communicate  with  the 
ganglion  below ;  external,  to  communicate  with  the  spinal  nerves ;  and 
internal,  to-  communicate  with  the  sympathetic  filaments  of  the  opposite 
side,  and  to  be  distributed  to  the  viscera. 

CRANIAL     GANGLIA. 

Ganglion  of  Ribes, 
Ciliary,  or  lenticular  ganglion, 
Spheno-palatine,  or  Meckel's  ganglion, 
Otic,  or  Arnold's  ganglion, 
Submaxillary  ganglion. 

The  GANGLION  OF  RIBES  is  a  small  ganglion  situated  upon  the  anterior 
communicating  artery,  and  formed  by  the  union  of  the  sympathetic  fila- 
ments which  accompany  the  ramifications  of  the  two  anterior  cerebral 
arteries.  These  filaments  are  derived  from  the  carotid  plexus  at  each 
side  ;  and  through  their  intervention,  the  ganglion  of  Ribes  is  brought  into 
connexion  with  the  carotid  plexus,  and  with  the  other  ganglia  of  the  sym- 
pathetic. This  ganglion,  though  of  very  small  size,  is  interesting,  as  being 
the  superior  point  of  union  between  the  sympathetic  chains  of  opposite 
sides  of  the  body. 

The  CILIARY  GANGLION  (knticuiar)  is  a  small  quadrangular  and  flattened 
37  2c 


434 


CILIARY    GANGLION. 


ganglion  situated  within  the  orbit,  between  the  optic  nerve  and  the  exter- 
nal rectus  muscle ;  it  is  in  close  contact  with  the  optic  nerve,  and  is  sur- 
rounded by  adipose  tissue,  which  renders  its  dissection  somewhat  difficult. 
Its  branches  of  distribution  are  the  ciliary,  which  arise  from  its  anterior 
angles  by  two  groups :  the  upper  group,  consisting  of  about  four  filaments ; 
and  the  lower,  of  five  or  six.  They  accompany  the  ciliary  arteries  in  a 

Fig.  196.*' 


waving  course,  and  divide  into  a  number  of  filaments  which  pierce  the 
sclerotic  around  the  optic  nerve,  and  supply  the  tunics  of  the  eyeball.  A 
small  filament  is  said  by  Tiedemann,  to  accompany  the  arteria  centralis 
retinae  into  the  centre  of  the  globe  of  the  eye. 

Its  branches  of  communication  are  three,  one,  the  long  root,  which  pro- 
ceeds from  the  posterior  superior  angle  to  the  nasal  branch  of  the  ophthal- 
mic nerve  ;  a  short  thick  branch,  the  short  root,  from  the  posterior  inferior 
angle  to  the  inferior  division  of  the  third"  nerve  ;  and  a  slender  filament, 
the  sympathetic  root,  which  passes  backwards  to  the  cavernous  sinus,  and 
communicates  with  the  carotid  plexus.  Occasionally  the  ciliary  ganglion 

*  The  crania]  ganglia  of  the  sympathetic  nerve.  1.  The  ganglion  of  Ribes.  2.  The 
filament  by  which  it  communicates  with  the  carotid  plexus  (3).  4.  The  ciliary  or  len- 
ticular ganglion,  giving  off  ciliary  branches  for  the  supply  of  the  globe  of  the  eye.  5. 
Part  of  the  inferior  division  of  the  third  nerve,  receiving  a  short  thick  branch  (the  short 
root)  from  the  ganglion.  6.  Part  of  the  nasal  nerve,  receiving  a  longer  branch  (the  Icng 
root)  from  the  ganglion.  7.  A  slender  filament  (the  sympathetic  root)  sent  directly 
backwards  from  the  ganglion  to  the  carotid  plexus.  8.  Part  of  the  sixth  nerve  in  the 
cavernous  sinus,  receiving  two  branches  from  the  carotid  plexus.  9.  Meckel's  ganglion 
(spheno-palatine).  10.  Its  ascending  branches,  communicating  with  the  superioNjriaxil- 
lary  nerve.  11.  Its  descending  or  palatine  branches.  12  Its  internal  branches,  spKerio- 
palatine  or  nasal.  13.  The  naso-palatine  branch,  one  of  the  nasal  branches.  *  The 
naso-palatine  ganglion.  14.  The  posterior  branch  of  the  ganglion,  the  Vidian  nerve. 
if1.  Its  carotid  branch  (n.  petrosus  profundus)  communicating  with  the  carotid  plexus. 
16.  Its  petrosal  branch  (n.  petrosus  superficialis  minor),  joining  the  intumescentia  gangh- 
onnisofthe  facial  nerve.  17.  The  facial  nerve.  18.  The  chorda  tympani  nerve,  which 
descends  to  join  the  gustatory  nerve.  19.  The  gustatory  nerve.  20.  The  submaxillary 
ganglion,  receiving  the  chorda  tympani,  and  other  filaments  from  the  gustatory.  21. 
The  superior  cervical  ganglion  of  the  sympathetic. 


SPHENO-PALATINE    GANGLION.  435 

receives  also  a  filament  of  communication  (middle  root)  from  the  spheno- 
palatine  ganglion ;  and  it  sometimes  sends  a  twig  to  the  abducens  nerve. 

The  SPHENO-PALATINE  GANGLION  (Meckel's)  the  largest  of  the  cranial 
ganglia  of  the  sympathetic,  is  very  variable  in  its  dimensions.  It  is 
situated  in  the  spheno-maxillary  fossa. 

Its  branches  are  divisible  into  four  groups ;  ascending,  descending,  in- 
ternal, and  posterior. 

The  branches  of  distribution  are  the  internal  and  the  descending.  The 
internal  branches  are  the  nasal  and  the  naso-palatine.  The  nasal  or 
spheno-palatine  nerves,  four  or  five  in  number,  enter  the  nasal  fossa  through 
the  spheno-palatine  foramen,  and  are  distributed  to  the  mucous  membrane 
of  the  superior  meatus,  and  superior  and  middle  spongy  bones.  Besides 
these,  several  branches  issue  through  small  openings  in  the  palate  and 
sphenoid  bone,  and  supply  the  mucous  membrane  of  the  \ipper  part  of  the 
pharynx  and  the  Eustachian  tube. 

The  naso-palatine  nerve  (Scarpa)  enters  the  nasal  fossa  with  the  nasal 
nerves,  and  crosses  the  roof  of  the  nares  to  reach  the  septum,  to  which  it 
gives  several  filaments.  It  then  curves  downwards  and  forwards  to  the 
naso-palatine  canal,  and  enters  the  anterior  palatine  canal,  where  it  joins 
with  its  fellow  of  the  opposite  side,  and  receives  filaments  from  the  ante- 
rior dental  and  palatine  nerves.  By  this  junction  an  enlargement  is 
formed,  the  naso-palatine  ganglion  (Cloquet's),  which  distributes  filaments 
to  the  mucous  membrane  of  the  palate,  immediately  behind  the  incisor 
teeth. 

The  descending  branches  are  the  three  palatine  nerves,  anterior,  middle, 
and  posterior. 

The  anterior  palatine  nerve,  the  largest  of  the  three,  descends  from  the 
ganglion  through  the  posterior  palatine  canal,  and  emerges  at  the  posterior 
palatine  foramen.  It  then  passes  forwards  in  the  substance  of  the  hard 
palate  to  which  it  is  distributed,  and  communicates  with  the  naso-palatine 
ganglion  and  with  its  branches.  While  in  the  posterior  palatine  canal  this 
nerve  gives  off  several  branches,  which  enter  the  nose  through  openings 
in  the  palate  bone,  and  are  distributed  to  the  middle  and  inferior  meatus, 
the  inferior  spongy  bone,  and  the  antrum. 

The  middle  palatine  nerve  descends  through  the  same  canal  to  the  pos- 
terior palatine  foramen,  and  distributes  branches  to  the  tonsil,  soft  palate, 
and  uvula. 

The  posterior  palatine  nerve,  the  smallest  of  the  three,  quits  the  other 
nerves  to  enter  a  distinct  canal,  from  which  it  emerges  by  a  separate  open- 
ing behind  the  posterior  palatine  foramen.  It  is  distributed  to  the  hard 
palate  and  gums  near  the  point  of  its  emergence,  and  to  the  tonsil  and 
soft  palate. 

The  branches  of  communication  are  the  ascending  and  the  posterioi. 
The  ascending  branches  are,  one  or  two  to  join  the  superior  maxillary 
nerve ;  one  to  the  abducens  nerve ;  one  to  the  ciliary  ganglion  constituting 
its  middle  root ;  and  occasionally  two  filaments  to  4he  optic  nerve  tvithm 
the  orbit.  The  posterior  branch  is  the  Vidian  or  pieiygoid  nerve. 

The  Vidian*  nerve  passes  directly  backwards  from  vhe  spheno-palatine 

*  Guiclo  Guidi,  latinized  into  Vidus  Vidius,  was  professor  of  anatomy  and  medicin* 
in  the  College  of  France  in  1542.  His  work  is  posthumous,  and  *vas  published  m 
16U. 


436  OTIC    GANGLION. 

ganglion,  through  the  pterygoid  or  Vidian  canal,  to  the  foramen  jacerum 
basis  cra'nii,  where  it  divides  into  two  branches,  the  carotid  and  petrosal. 
The  carotid  branch  (n.  petrosus  profundus)  crosses  the  foramen  lacerum, 
surrounded  by  the  ligamentous  substance  which  closes  that  opening  and 
enters  the  carotid  canal  by  several  filaments  to  join  the  carotid  plexus. 
The  petrosal  branch  (n.  petrosus  superficial  major)  enters  the  cranium 
through  the  foramen  lacerum  basis  cranii,  piercing  the  ligamentous  sub- 
stance of  the  latter,  and  passes  backwards  beneath  the  Casserian  ganglion 
and  dura  mater,  embedded  in  a  groove  upon  the  anterior  surface  of  the 
petrous  bone,  to  the  hiatus  Fallopii.  In  the  hiatus  Fallopii  the  petrosal 
branch  of  the  Vidian  receives  a  twig  from  Jacobson's  nerve,  and  termi- 
nates in  the  intumescentia  gangliformis  of  the  facial  nerve. 

While  in  the  pterygoid  canal  the  Vidian  nerve  sends  off  a  minute 
branch  which  passes  through  an  opening  in  the  sphenoid  bone  and  joins 
the  otic  ganglion. 

The  OTIC  GANGLION  (Arnold's)*  is  a  small  oval-shaped  and  flattened 
ganglion,  resting  against  the  inner  surface  of  the  inferior  maxillary  nerve, 
immediately  below  the  foramen  ovale  ;  it  is  in  relation  externally  with  the 
trunk  of  the  inferior  maxillary  nerve,  just  at  the  point  of  union  of  the  motor 
root ;  internally  it  rests  against  the  cartilage  of  the  Eustachian  tube  and 
tensor  palati  muscle  ;  and  posteriorly  it  is  in  contact  with  the  arteria  me- 
ningea  media.  It  is  closely  adherent  to  the  internal  pterygoid  nerve,  and 
appears  like  a  swelling  upon  that  branch. 

The  branches  of  the  otic  ganglion  are  seven  in  number ;  two  of  distri- 
bution, and  five  of  communication. 

The  branches  of  distribution  are,  a  small  filament  to  the  tensor  tympani 
muscle,  and  one  to  the  tensor  palati  muscle  ;  the  latter  is  usually  derived 
from  the  internal  pterygoid  nerve,  at  the  point  where  that  nerve  is  enclosed 
by  the  ganglion. 

The  branches  of  communication  are,  two  or  three  filaments  to  the  outer 
portion  of  the  inferior  maxillary  nerve ;  one  or  two  filaments  to  the  auri- 
cular nerve ;  a  filament  to  the  chorda  tympani ;  filaments  to  the  arteria 
meningea  media  to  communicate  with  the  nervi  molles ;  a  filament  which 
enters  the  cranium  through  the  foramen  spinosum  with  the  arteria  me- 
ningea media,  and  accompanies  the  nervus  petrosus  superficialis  minor  to 
the  hiatus  Falopii,  where  it  joins  the  intumescentia  gangliformis  of  the 
facial  nerve ;  a  filament  which  enters  the  cranium  through  a  small  canal 
behind  the  foramen  rotundum  to  join  the  Casserian  ganglion;  a  filaaaent 
which  enters  a  small  canal  near  the  foramen  ovale  to  communicate  with 
the  Vidian  nerve ;  and  the  nervus  petrosus  superficialis  minor.  The  latter 
nerve  ascends  from  the  ganglion  to  a  small  canal  situated  between  the 
foramen  ovale  and  foramen  spinosum,  and  passes  backwards  on  the 
petrous  bone  to  the  hiatus  Falopii,  where  it  divides  into  two  filaments. 
One  of  these  filaments  enters  the  hiatus  and  joins  the  intumescentia  gan- 
gliformis of  the  facial ;  the  other  passes  to  a  minute  foramen  nearer  the 
base  of  the  petrous  bone  and  enters  the  tympanum,  where  it  communicates 
with  a  branch  of  Jacobson's  nerve. 

The  SUBMAXIL^ARY  GANGLION  is  a  small  round  or  triangular  ganglion, 

•Frederick  Arnold,  "Dissertatio  Inauguralis  de  Parte  Cepbalica  Nervi  Sympathetic!," 
Heidelberg,  1826;  and  '-IJeber  den  Ohrknoten,"  1828 


CERVICAL    GANGLIA.  437 

situated  upon  the  submaxillary  gland,  in  close  relation  with  the  gustatory 
nerve  and  near  the  posterior  border  of  the  mylo-hyoideus  muscle. 

Its  branches  of  distribution,  six  or  eight  in  number,  divide  into  many 
filaments,  which  supply  the  substance  of  the  submaxillary  gland  and 
Wharton's  duct. 

Its  branches  of  communication  are,  two  or  three  from  and  to  the  gusta- 
tory nerve  ;  one  from  the  chorda  tympani ;  and  one  or  two  filaments  which 
pass  to  the  facial  artery  and  communicate  with  the  nervi  molles  from  the 
cervical  portion  of  the  sympathetic. 

CAROTID  PLEXUS. — The  ascending  branch  of  the  superior  cervical  gan- 
glion enters  the  carotid  canal  with  the  internal  carotid  artery,  and  divides 
into  two  branches,  which  form  several  loops  of  communication  with  each 
other  around  the  artery.  These  branches,  together  with  those  derived 
from  the  petrosal  branch  of  the  Vidian,  constitute  the  carotid  plexus.  They 
also  form  frequently  a  small  gangliform  swelling  upon  the  under  part  of  the 
artery,  which  is  called  the  carotid  ganglion.  The  latter,  however,  is  not 
constant.  The  continuation  of  the  carotid  plexus  onwards  with  the  artery 
by  the  side  of  the  sella  turcica,  is  called  the  cavernous  plexus. 

The  carotid  plexus  is  the  centre  of  communication  between  all  the  cra- 
nial ganglia ;  and  being  derived  from  the  superior  cervical  ganglion,  be- 
tween the  cranial  ganglia  and  those  of  the  trunk,  it  also  communicates 
with  the  greater  part  of  the  cerebral  nerves,  and  distributes  filaments  with 
each  of  the  branches  of  the  internal  carotid,  which  accompany  those 
branches  in  all  their  ramifications. 

Thus,  the  Ganglion  of  Ribes  is  formed  by  the  union  of  the  filaments 
which  accompany  the  anterior  cerebral  arteries,  and  which  meet  on  the 
anterior  communicating  artery.  The  ciliary  ganglion  communicates  with 
the  plexus  by  means  of  the  long  branch  which  is  sent  back  to  join  it  in 
the  cavernous  sinus.  The  spheno-palatine,  and  with  it  the  naso-palatine 
ganglion,  joins  the  plexus  by  means  of  the  carotid  branch  of  the  Vidian. 
The  submaxillary  ganglion  is  brought  into  connexion  with  it  by  means  of 
the  otic  ganglion,  and  the  otic  ganglion  by  means  of  the  tympanic  nerve 
and  the  Vidian. 

It  communicates  with  the  third  nerve  in  the  cavernous  sinus,  and  through 
the  ciliary  ganglion ;  frequently  with  the  fourth  in  the  formation  of  the 
nerve  of  the  tentorium ;  with  the  Casserian  ganglion  ;  with  the  ophthalmic 
division  of  the  fifth  in  the  cavernous  sinus,  and  by  means  of  the  ciliary 
ganglion ;  with  the  superior  maxillary,  through  the  spheno-palatine  gan- 
glion ;  and  with  the  inferior  maxillary,  through  the  otic  ganglion.  It  sends 
two  branches  directly  to  the  sixth  nerve,  which  unite*  with  it  as  it  crosses 
the  cavernous  sinus ;  it  communicates  with  the  facial  and  auditory  nerves, 
through  the  medium  of  the  petrosal  branch  of  the  Vidian ;  and  with  the 
glosso-pharyngeal  by  means  of  two  filaments  to  the  tympanic  nerve. 


CERVICAL    GANGLIA, 


The  Superior  cervical  ganglion  is  long  and  fusiform,  of  a  greyish  colour, 
smooth,  and  of  considerable  thickness,  extending  from  within  an  inch  of 

*  Panizza,  in  his  "Experimental  Researches  on  the  Nerves,"  denies  this  communica- 
tion, and  states  very  vaguely  that  "they  are  merely  lost  and  entwined  around  it"-- 
Edinburgh  Medical  and  Surgical  Journal.  January  1836. 

37* 


438  INFERIOR    CERVICAL    GANGLION. 

• 

the  carotid  foramen  in  the  petrous  bone  to  opposite  the  lower  border  of 
the  third  cervical  vertebra.  It  is  in  relation  in  front  with  the  sheath  of  the 
internal  carotid  artery  and  internal  jugular  vein;  and  behind  with  the 
rectus  anticus  major  muscle. 

Its  branches,  like  those  of  all  the  sympathetic  ganglia  in  the  trunk,  are 
divisible  into  superior,  inferior,  external,  and  internal;  to  which  may  be 
added,  as  proper  to  this  ganglion,  anterior. 

The  superior  (carotid  nerve)  is  a  single  branch  which  ascends  by  the 
side  of  the  internal  carotid,  and  divides  into  two  branches ;  one  lying  to 
the  outer  side,  the  other  to  the  inner  side  of  that  vessel.  The  two  branches 
enter  the  carotid  canal,  and  by  their  communications  with  each  other  and 
with  the  petrosal  branch  of  the  Vidian,  constitute  the  carotid  plexus. 

The  inferior  or  descending  branch,  sometimes  two,  is  the  cord  of  com- 
munication with  the  middle  cervical  ganglion. 

The  external  branches  are  numerous,  and  may  be  divided  into  two  sets : 
those  which  communicate  with  the  glosso-pharyngeal,  pneumogastric,  and 
hypoglossal  nerves;  and  those  which  communicate  with  the  three  first 
cervical  nerves. 

The  internal  branches  are  three  in  number:  pharyngeal,  to  assist  in 
forming  the  pharyngeal  plexus;  laryngeal,  to  join  the  superior  laryngeal 
nerve  and  its  branches ;  and  the  superior  cardiac  nerve,  or  nervus  super- 
ficialis  cordis. 

The  anterior  branches  accompany  the  carotid  artery  with  its  branches, 
around  which  they  form  intricate  plexuses,  and  here  and  there  small  gan- 
glia; they  are  called,  from  the  softness  of  their  texture,  nervi  molles,  and 
from  their  reddish  hue,  nervi  subrufi. 

The  Middle  cervical  ganglion  (thyroid  ganglion)  is  of  small  size,  and 
sometimes  altogether  wanting.  It  is  situated  opposite  the  fifth  cervical 
vertebra,  and  rests  upon  the  inferior  thyroid  artery.  This  relation  is  so 
constant,  as  to  have  induced  Haller  to  name  it  the  "thyroid  ganglion." 

Its  superior  branch,  or  branches,  ascend  to  communicate  "with  the  supe- 
rior cervical  ganglion. 

Its  inferior  branches  descend  to  join  the  inferior  cervical  ganglion  ;  one 
of  these  frequently  passes  in  front  of  the  subclavian  artery,  the  other  be- 
hind it. 

Its  external  branches  communicate  with  the  third,  fourth,  and  fifth  cer- 
vical nerves. 

Its  internal  branches  are,  filaments  which  accompany  the  inferior  thyroid 
artery,  the  inferior  thyroid  plexus ;  and  the  middle  cardiac  nerve,  nervus 
cardiacus  magnus. 

The  INFERIOR  CERVICAL  GANGLION  (vertebral  ganglion)  is  much  larger 
than  the  preceding,  and  is  constant  in  its  existence.  It  id  of  a  semilunar 
form,  and  is  situated  upon  the  base  of  the  transverse  process  of  the  seventh 
cervical  vertebra,  immediately  behind  the  vertebral  artery :  hence  its  tide 
to  the  designation  "  vertebral  ganglion" 

Its  superior  branches  communicate  with  the  middle  cervical  ganglion. 

The  inferior  branches  pass  some  before  and  some  behind  the  subclavian 
artery,  to  join  the  first  thoracic  ganglion. 

The  external  branches  consist  of  two  sets;  one  which  communicates 
with  the  sixth,  seventh,  and  eighth  cervical  and  first  dorsal  nerve;  *ud 


CARDIAC    NERVES. 


439 


Fig.  197/j- 


one  which  accompanies  the  verte- 
bral artery  along  the  vertebral  ca- 
nal, forming  the  vertebral  plexus. 
This  plexus  sends  filaments  to  all 
the  branches  given  off  by  the  ar- 
tery, and  communicates  in  the 
cranium  with  the  filaments  of  the 
carotid  plexus  accompanying  the 
branches  of  the  internal  carotid 
arteiy. 

The  internal  branch  is  the  infe- 
rior cardiac  nerve,  nervus  cardiacus 
minor. 

CARDIAC  NERVES.* — The  supe- 
rior cardiac  nerve  (nervus  superfi- 
cialis  cordis]  arises  from  the  lower 
part  of  the  superior  cervical  gan- 
glion ;  it  then  descends  the  neck 
behind  the  common  carotid  artery 
and  parallel  with  the  trachea, 
crosses  the  inferior  thyroid  artery, 
and  running  by  the  side  of  the  re- 
current laryngeal  nerve  for  a  short 
distance,  passes  behind  the  arteria 
innominata  to  the  concavity  of  the 
arch  of  the  aorta,  where  it  joins  the 
cardiac  ganglion. 

In  its  course  it  receives  branches 
from  the  pneumogastric  nerve,  and 
sends  filaments  to  the  thyroid 
gland  and  trachea. 

The  Middle  cardiac  nerve  (ner- 
vus cardiacus  magnus]  proceeds 
from  the  middle  cardiac  ganglion, 
or,  in  its  absence,  from  the  cord 
of  communication  between  the 
superior  and  inferior.  It  is  the 
largest  of  the  three  nerves,  and  lies 
nearly  parallel  with  the  recurrent 

*  There  is  no  constancy  with  regard  to  the  origin  and  course  of  these  nerves;  theie- 
fore  the  student  must  not  be  disappointed  in  finding  the  description  in  discord  with  HIS 
dissection. 

•\  A  view  of  the  great  sympathetic  nerve.  36.  The  cavity  of  the  cranium.  34.  The 
globe  of  the  eye.  33.  The  septum  of  the  nose.  32.  The  incisor  teeth.  31.  The  sub 
maxillary  gland.  30.  The  larynx.  29.  The  heart.  28.  The  left  lung.  *  The  coeliac 
axis.  27.  The  ascending  vena  cava.  26.  The  kidney.  25.  The  crista  of  the  ilium 
23.  The  bladder.  22.  The  rectum.  24.  The  pubes.  1.  Plexus  on  the  carotid  artery  in 
the  carotid  foramen.  2.  Sixth  nerve,  (motor  externus.)  3.  1st  of  the  fifth  or  ophthal 
mic  nerve.  4.  Branch  on  the  septum  narium,  connecting  Meckel's  ganglion  with  Clo 
quet's  in  the  incisive  foramen.  5.  Immediately  above  the  figure  is  the  recurrent  branch 
or  Vidian  nerve,  dividing  into  the  carotid  and  petrosal  branches.  6.  Posterior  palatin* 
branches.  7.  Lingual  nerve  joined  by  the  chorda  tympani.  8.  The  portio  dura  of  th» 
seventh  pair  or  facial  nerve.  9.  The  superior  cervical  ganglion.  10.  The  middle  ce* 


440  THORACIC    GANGLIA. 

larvngeal,  At  the  root  of  the  neck  it  divides  into  several  branches,  \vhick 
pass  some  before  and  some  behind  the  subclavian  artery;  it  communicates 
with  the  superior  and  inferior  cardiac,  and  with  the  pneumogastric  and 
recurrent  nerves,  and  descends  to  the  bifurcation  of  the  trachea,  to  the 
great  cardiac  plexus. 

The  Inferior  cardiac  nerve  (nervus  cardiacus  minor)  arises  from  the  in- 
ferior cervical  ganglion,  communicates  freely  with  the  recurrent  laryngeal 
and  middle  cardiac  nerves,  and  descends  to  the  front  of  the  bifurcation 
of  the  trachea,  to  join  the  great  cardiac  plexus. 

The  Cardiac  ganglion  is  a  ganglionic  enlargement  of  variable  size,  situ- 
ated beneath  the  arch  of  the  aorta,  to  the  right  side  of  the  ligament  of  the 
ductus  arteriosus.  It  receives  the  superior  cardiac  nerves  of  opposite 
sides  of  the  neck  and  a  branch  from  the  pneumogastric,  and  gives  off  nu- 
merous branches  to  the  cardiac  plexuses. 

The  Great  cardiac  plexus  is  situated  upon  the  bifurcation  of  the  trachea, 
above  the  right  pulmonary  artery,  and  behind  the  arch  of  the  aorta.  It  is 
formed  by  the  convergence  of  the  middle  and  inferior  cardiac  nerves,  and 
by  branches  from  the  pneumogastric  and  descendens  noni  nerve,  and  first 
thoracic  ganglion. 

The  interior  cardiac  plexus  is  situated  in  front  of  the  ascending  aorta, 
near  its  origin.  It  is  formed  by  the  communications  of  filaments  that  pro- 
ceed from  three  different  sources,  namely,  from  the  superior  cardiac  nerves, 
crossing  the  arch  of  the  aorta ;  from  the  cardiac  ganglion  beneath  the 
arch ;  and  from  the  great  cardiac  plexus,  passing  between  the  ascending 
aorta  and  the  right  auricle.  The  anterior  cardiac  plexus  supplies  the  an- 
terior aspect  of  the  heart,  distributing  numerous  filaments  with  the  left 
coronary  artery,  which  form  the  anterior  coronary  plexus. 

The  Posterior  cardiac  plexus  is  formed  by  numerous  branches  from  the 
great  cardiac  plexus,  and  is  situated  upon  the  posterior  part  of  the  ascend- 
ing aorta,  near  its  origin.  It  divides  into  two  sets  of  branches :  one  set 
accompanying  the  right  coronary  artery  in  the  auriculo-ventricular  sulcus ; 
the  other  set  joining  the  artery  on  the  posterior  aspect  of  the  heart.  They 
both  together  constitute  the  posterior  coronary  plexus. 

The  great  cardiac  plexus  likewise  gives  branches  to  the  auricles  of  the 
heart,  and  others  to  assist  in  forming  the  anterior  and  posterior  pulmonary 
plexuses. 

THORACIC    GANGLIA. 

The  Thoracic  ganglia  are  twelve  in  number  on  each  side.  They  are 
flattened  and  triangular,  or  irregular  in  form,  and  present  the  peculiar  grey 
colour  and  pearly  lustre  of  the  other  sympathetic  ganglia ;  they  rest  upon 
the  heads  of  the  ribs,  and  are  covered  in  by  the  pleura  costalis.  The  two 
first  ganglia  and  the  last  are  usually  the  largest. 

Their  branches  are  superior,  inferior,  external,  and  internal. 

The  superior  and  inferior  are  prolongations  of  the  substance  of  the  gan- 
glia rather  than  branches  ;  the  former  to  communicate  with  the  gangiion 
above,  the  latter  with  that  below. 

vical  ganglion.  11.  The  inferior  cervical  ganglion.  12.  The  roots  of  the  great  splanch- 
nic norve,  arming  from  the  dorsal  ganglia.  13.  The  lesser  splanchnic  nerve.  14.  The 
lenal  plexus.  15.  The  solar  plexus.  16.  The  mesenteric  plexus.  17.  The  lumbar 
ganglia.  1  8.  The  sacral  ganglia.  19.  The  vesical  plexus.  20.  The  rectal  plexus.  21. 
The  himba:  plexus,  (cerebro-spinal.) 


LUMBAR    GANGLIA.  441 

The  external  branches,  two  or  three  in  number,  communicate  with  both 
roots  of  each  of  the  spinal  nerves. 

The  internal  branches  of  the  five  upper  ganglia  are  pulmonary  to  join 
the  pulmonary  plexuses ;  cesophageal  to  the  cesophageal  plexus  and  aortic 
to  the  thoracic  aorta  and  its  branches ;  the  first  thoracic  ganglion  more- 
over sends  branches  to  the  cardiac  plexuses.  The  branches  of  the  lower 
ganglia  are  aortic,  and  several  large  cords  which  unite  to  form  the  two 
splanchnic  nerves. 

The  Great  splanchnic  nerve  arises  from  the  sixth  dorsal  ganglion,  and 
receives  branches  from  the  seventh,  eighth,  ninth,  and  tenth,  which  aug- 
ment it  to  a  nerve  of  considerable  size.  It  descends  in  front  of  the  verte- 
bral column,  within  the  posterior  mediastinum,  pierces  the  diaphragm 
immediately  to  the  outer  side  of  each  crus,  and  terminates  in  the  semilunar 
ganglion. 

The  Lesser  splanchnic  nerve  (renal")  is  formed  by  filaments  from  the 
tenth,  eleventh,  and  sometimes  from  the  twelfth  dorsal  ganglion.  It 
pierces  the  diaphragm,  and  descends  to  join  the  renal  plexus. 

The  Semilunar  ganglion  is  a  large,  irregular,  gangliform  body,  pierced 
by  numerous  openings,  and  appearing  like  the  aggregation  of  a  number 
of  smaller  ganglia,  having  spaces  between  them.  It  is  situated  by  the 
side  of  the  ccelic  axis,  and  communicates  with  the  ganglion  of  the  oppo- 
site side,  both  above  and  below  that  trunk,  so  as  to  form  a  gangliform 
circle,  from  which  branches  pass  off  in  all  directions,  like  rays  from  a 
centre.  Hence  the  entire  circle  has  been  named  the  solar  plexus. 

The  Solar  plexus  receives  the  great  splanchnic  nerves  ;  part  of  the  lesser 
splanchnic  nerves ;  the  termination  of  the  right  pneumogastric  nerve  ;  some 
branches  from  the  right  phrenic  nerve ;  and  sometimes  one  or  two  fila- 
ments from  the  left.  It  sends  numerous  filaments,  which  accompany, 
under  the  name  of  plexuses,  all  the  branches  given  off  by  the  abdominal 
aorta.  Thus,  we  have  derived  from  the  solar  plexus  the — 
Phrenic  plexuses,  Renal  plexuses, 

Gastric  plexus,  Superior  mesenteric  plexus, 

Hepatic  plexus,  Spermatic  plexuses, 

Splenic  plexus,  Inferior  mesenteric  plexus. 

Supra-renal  plexuses, 

The  Renal  plexus  is  formed  chiefly  by  the  lesser  splanchnic  nerve,  but 
receives  many  filaments  from  the  solar  plexus. 

The  Spermatic  plexus  is  formed  principally  by  the  renal  plexus. 

The  Inferior  mesenteric  plexus  receives  filaments  from  the  aortic  plexus. 

.LUMBAR    GANGLIA. 

The  Lumbar  ganglia  are  four  in  number  on  each  side,  of  the  peculiar 
pearly  grey  colour,  fusiform,  and  situated  upon  the  anterior  part  of  the 
bodies  of  the  lumbar  vertebrae. 

The  superior  and  inferior  branches  of  the  lumbar  ganglia  are  branches 
of  communication  with  the  ganglion  above  and  below,  as  in  the  dorsal 
region. 

The  external  branches,  two  or  three  in  number,  communicate  with  the 
lumbar  nerves. 

The  internal  branches  consist  of  two  sets ;  of  which  the  upper  pass  in 
wards  in  front  of  the  abdominal  aorta,  and  form  around  that  trunk  a  plex 


442  ORGANS    OF    SENSE. 

iform  interlacement,  which  constitutes  the  lumbar  aortic  plexus  ;  the  lower 
branches  cross  the  common  iliac  arteries,  and  unite  over  the  promontory 
of  the  sacrum,  to  form  the  hypogastric  plexus. 

The  Lumbar  aortic  plexus  is  formed  by  branches  from  the  lumbar  gan- 
glia, and  receives  filaments  from  the  solar  and  superior  mesenteric  plex- 
uses. It  sends  filaments  to  the  inferior  mesenteric  plexus,  and  terminates 
in  the  hypogastric  plexus. 

The  Hypogastric  plexus  is  formed  by  the  termination  of  the  aortic 
plexus,  and  by  the  union  of  branches  from  the  lower  lumbar  ganglia.  It 
is  situated  over  the  promontory  of  the  sacrum,  between  the  two  common 
iliac  arteries,  and  bifurcates  inferiorly  into  two  lateral  portions,  which 
communicate  with  branches  from  the  fourth  and  fifth  sacral  nerves.  It 
distributes  branches  to  all  the  viscera  of  the  pelvis,  and  sends  filaments 
which  accompany  the  branches  of  the  internal  iliac  artery. 

SACRAL    GANGLIA. 

The  Saciui  ganglia  are  four  or  five  in  number  on  each  side.  They  are 
situated  upon  the  sacrum,  close  to  the  anterior  sacral  foramina,  and  re- 
semble the  lumbar  ganglia  in  form  and  mode  of  connexion,  although  much 
smaller  in  size. 

The  superior  and  inferior  branches  communicate  with  the  ganglia  above 
and  below. 

The  external  branches  communicate  with  the  sacral  nerves. 

The  internal  branches  communicate  very  freely  with  the  lateral  divisions 
of  the  hypogastric  plexus,  and  are  distributed  to  the  pelvic  viscera.  The 
last  pair  of  sacral  ganglia  give  off  branches  which  join  a  small  ganglion, 
situated  on  the  first  bone  of  the  coccyx,  called  the  ganglion  impar,  or 
azygos.  This  ganglion  resembles  in  its  position  and  function  the  ganglion 
of  Ribes,  serving  to  connect  the.  inferior  extremity  of  the  sympathetic  sys- 
tem, as  does  the  former  ganglion  its  upper  extremity.  It  gives  off  a  few 
small  branches  to  the  coccyx  and  rectum. 


CHAPTER  X. 

ORGANS    OF    SENSE. 

THE  organs  of  sense,  the  instruments  by  which  the  animal  frame  is 
brought  into  relation  with  surrounding  nature,  are  five  in  number.  Four 
of  these  organs  are  situated  within  the  head :  viz.  the  apparatus  of  smell, 
sight,  hearing,  and  taste ;  and  the  remaining  organ,  of  touch,  is  resident 
in  the  skin,  and  distributed  over  the  surface  of  the  body. 

THE    NOSE    AND    NASAL    F  O  S  S  JE 

The  organ  of  smell  consists  essentially  of  two  parts:  one  external,  the 
nose ;  the  other  internal,  the  nasal  fossae. 

The  nose  is  the  triangular  pyramid  wrhich  projects  from  the  centre  of 
the  face,  immediately  above  the  upper  lip.  Superiorly  it  is  connected 


STRUCTURE    OF    THE    .NOSE.  443 

with  the  forehead  by  means  of  a  narrow  bridge  ;  inferiorly,  it  presents  two 
openings,  the  nostrils,  which  overhang  the  mouth,  and  are  so  constructed 
that  the  odour  of  all  substances  must  be  received  by  the  nose  before  they 
can  be  introduced  within  the  lips.  The  septum  between  the  openings  of 
the  nostrils  is  called  the  columna.  Their  entrance  is  guarded  by  a  num- 
ber of  stiff  hairs  (vibrissa)  which  project  across  the  openings,  and  act  as  a 
filter  in  preventing  the  introduction  of  foreign  substances,  such  as  dust  or 
insects,  with  the  current  of  air  intended  for  respiration. 

The  anatomical  elements  of  which  the  nose  is  composed,  are — 1.  In- 
tegument. 2.  Muscles.  3.  Bones.  4.  Fibro-cartilages.  5.  Mucous 
membrane.  6.  Vessels  and  nerves. 

1.  The  Integument  forming  the  tip  (lobulus)  and  wings  (alee)  of  the  nose 
is  extremely  thick  and  dense,  so  as  to  be  with  difficulty  separated  from 
the  fibro-cartilage.     It  is  furnished  with  an  abundance  of  sebiparous  folli- 
cles, which,  by  their  oily  secretion,  protect  the  extremity  of  the  nose  in 
excessive  alternations  of  temperature.     The  sebaceous  matter  of  these  fol- 
licles becomes  of  a  dark  colour  upon  the  surface,  from  the  attraction  of  the 
carbonaceous  matter  floating  in  the  atmosphere ;  hence  the  spotted  ap- 
pearance which  the  tip  of  the  nose  presents  in  large  cities.     When  the 
integument  is  firmly  compressed,  the  inspissated  sebaceous  secretion  is 
squeezed  out  from  the  follicles,  and  taking  the  cylindrical  form  of  their 
excretory  ducts,  has  the  appearance  of  small  white  maggots  with  black 
heads. 

2.  The  Muscles  are  brought  into  view  by  reflecting  the  integument : 
they  are  the  pyramidalis  nasi,  compressor  nasi,  dilatator  naris,  levator  labii 
superioris  alaeque  nasi,  and  depressor  labii  superioris  alaeque  nasi.     They 
have  been  already  described  with  the  muscles  of  the  face. 

3.  The  Bones  of  the  nose  are,  the  nasal,  and  nasal  processes'of  the  su- 
perior maxillary. 

4.  The  Fibro-cartilages  give  form  and  stability  to 

the  outwork  of  the  nose,  providing,  at  the  same  time,  Fis-  198-* 

by  their  elasticity,  against  injuries.     They  are  five  in 
number,  namely,  the — 

Fibro-cartilage  of  the  septum, 
Two  lateral  nbro-cartilages, 
Two  alar  fibro-cartilages. 

The  Fibro-cartilage  of  the  septum,  somewhat  trian- 
gular in  form,  divides  the  nose  into  its  two  nostrils. 
It  is  connected  above  with  the  nasal  bones  and  lateral 
fibro-cartilages  ;  behind,  with  the  ethmoidal  septum 
and  vomer ;  and  below,  with  the  palate  processes  of 
the  superior  maxillary  bones.  The  alar  fibro-carti- 
lages and  columna  move  freely  upon  the  fibro-€artilage 
of  the  septum,  being  but  loosely  connected  with  it  by 
perichondrium. 

The  Lateral  fibro-cartilages  are  also  triangular:  they  are  connected,  in 
front,  with  the  fibro-cartilage  of  the  septum  ;  above,  with  the  nasal  bones ; 

*  The  fibro-cartilages  of  the  nose.  1.  One  of  the  nasal  bones.  2.  The  fibro-cartilage 
of  the  septum.  3.  The  lateral  fibro-cartilage.  4.  The  alar  fibro-cartilage.  5.  Th« 
central  portions  of  the  alar  fibro-cartilages  which  constitute  the  colemna.  6.  The  up- 
penclix  of  the  alar  fibro-cartilage.  7.  The  nostril. 

35 


444  NASAL    FOSSAE. 

behind,  with  the  nasal  processes  of  the  superior  maxillary  bones ;  and  below 
with  the  alar  fibro-cartilages. 

Jllar  fibro-cartilages. — Each  of  these  cartilages  is  curved  in  such  a  man- 
ner as  to  correspond  with  the  opening  of  the  nostril,  to  which  it  forms  a 
kind  of  rim.  The  inner  portion  is  loosely  connected  with  the  same  part 
of  the  opposite  cartilage,  so  as  to  form  the  columna.  It  is  expanded  and 
thickened  at  the  point  of  the  nose  to  constitute  the  lobe  ;  and  on  the  side 
forms  a  curve  corresponding  with  the  form  of  the  ala.  This  curve  is  pro- 
longed downwards  and  forwards  in  the  direction  of  the  posterior  border 
of  the  ala  by  three  or  four  small  nbro-cartilaginous  plates,  which  are  ap- 
pendages of  the  alar  fibre-cartilage. 

The  whole  of  these  fibro-cartilages  are  connected  with  each  other  and 
to  the  bones,  by  perichondrium,  which,  from  its  membranous  structure, 
permits  of  the  freedom  of  motion  existing  between  them. 

5.  The  Mucous  membrane,  lining  the  interior  of  the  nose,  is  continuous 
with  the  skin  externally,  and  with  the  pituitary  membrane  of  the  nasal 
fossae  within.     Around  the  entrance  of  the  nostrils  it  is  provided  with 
numerous  vibrissce. 

6.  Vessels  and  Nerves.  —  The  Arteries  of  the  nose  are  the  lateralis  nasi 
from  the  facial,  and  the  nasalis  septi  from  the  superior  coronary. 

Its  Nerves  are,  the  facial,  infra-orbital,  and  nasal  branch  of  the  oph- 
thalmic. 

NASAL    FOSSJE. 

To  obtain  a  good  view  of  the  nasal  fosses,  the  face  must  be  divided 
through  the  nose  by  a  vertical  incision,  a  little  to  one  side  of  the  middle 
line. 

The  Nasalfossa  are  two  irregular  compressed  cavities,  extending  back- 
wards from  the  nose  to  the  pharynx.  They  are  bounded  superiorly  by  the 
lateral  cartilage  of  the  nose,  and  by  the  nasal,  sphenoid,  and  ethmoid 
bones ;  inferiorly  by  the  hard  palate ;  and,  in  the  middle  line,  they  are 
separated  from  each  other  by  a  bony  and  nbro-cartilaginous  septum.  A 
plan  of  the  boundaries  of  the  nasal  fossae  will  be  found  at  page  91. 

Upon  the  outer  wall  of  each  fossa,  in  the  dried  skull,  are  three  project- 
ing processes,  termed  spongy  bones.  The  two  superior  belong  to  the 
ethmoid,  the  inferior  is  a  separate  bone.  In  the  fresh  fossae  these  are 
covered  with  mucous  membrane,  and  serve  to  increase  the  surface  of  that 
membrane  by  their  prominence  and  convoluted  form.  The  space  inter- 
vening between  the  superior  and  middle  spongy  bone  is  the  superior 
meatus ;  the  space  between  the  middle  and  inferior  the  middle  meatus ; 
and  that  between  the  inferior  and  the  floor  of  the  fossa  the  inferior 
meatus. 

These  meatuses  are  passages  which  extend  from  before  backwards,  and 
it  is  in  rushing  through  and  amongst  these  that  the  atmosphere  deposits 
its  odorant  particles  upon  the  mucous  membrane.  There  are  several 
openings  into  the  nasal  fossae :  thus,  in  the  superior  meatus  are  the  openings 
of  the  sphenoidal  and  posterior  ethmoidal  cells ;  in  the  middle  the  anterior 
ethmoidal  cells,  the  frontal  sinuses,  and  the  antrum  maxillare ;  and,  in  the 
inferior  meatus,  the  termination  of  the  nasal  duct.  In  the  dried  bone 
'here  are  two  additional  openings,  the  spheno-palatine  and  the  anterior 
palatine  foramen  ;  the  former  being  situated  in  the  superior,  and  the  latter 
in  the  inferior  meatus. 


EYE SCLEROTIC    COAT.  445 

The  Mucous  membrane  of  the  nasal  fossae  is  called  pituitary,  or  Schnei- 
derian*  The  former  name  being  derived  from  the  nature  of  its  secretion, 
the  latter  from  Schneider,  who  was  the  first  to  show  that  the  secretion  of 
the  nose  proceeded  from  the  mucous  membrane,  and  not  from  the  brain, 
as  was  formerly  imagined.  It  is  continuous  with  the  general  gastro-pul- 
monary  mucous  membrane,  and  may  be  traced  through  the  openings  in 
the  meatuses,  into  the  sphenoidal  and  ethmoidal  cells ;  into  the  frontal 
sinuses ;  into  the  antrum  maxillare  ;  through  the  nasal  duct  to  the  surface 
of  the  eye,  where  it  is  continuous  with  the  conjunctiva ;  along  the  Eusta- 
chian  tubes  into  the  tympanum  and  mastoid  cells,  to  which  it  forms  the 
lining  membrane ;  and  through  the  posterior  nares  into  the  pharynx  and 
mouth,  and  thence  through  the  lungs  and  alimentary  canal. 

The  surface  of  this  membrane  is  furnished  with  a  columnar  epithelium 
supporting  innumerable  vibratile  cilia. 

Vessels  and  Nerves.  —  The  Arteries  of  the  nasal  fossae  are  the  anterior 
and  posterior  ethmoidal,  from  the  ophthalmic  artery ;  and  the  spheno- 
palatine  and  pterygo-palatine  from  the  internal  maxillary. 

The  Nerves  are,  the  olfactory,  the  spheno-palatine  branches  from  Meckel's 
ganglion,  and  the  nasal  branch  of  the  ophthalmic.  The  ultimate  filaments 
of  the  olfactory  nerve  terminate  in  papillae. 


THE    EYE,   WITH   ITS    APPENDAGES. 

The  form  of  the  eyeball  is  that  of  a  sphere,  of  about  one  inch  in  diame- 
ter, having  the  segment  of  a  smaller  sphere  engrafted  upon  its  anterior 
surface,  which  increases  its  antero-posterior  diameter.  The  axes  of  the 
two  eyeballs  are  parallel  with  each  other,  but  do  not  correspond  with  the 
axes  of  the  orbits,  which  are  directed  outwards.  The  optic  nerves  follow 
the  direction  of  the  orbits,  and  therefore  enter  the  eyeballs  to  their  nasa] 
side. 

The  Globe  of  the  Eye  is  composed  of  tunics,  and  of  refracting  media 
called  humours.  The  tunics  are  three  in  number,  the 

1.  Sclerotic  and  Cornea, 

2.  Choroid,  Iris,  and  Ciliary  processes, 

3.  Retina  and  Zonula  ciliaris. 

The  humours  are  also  three — 

Aqueous, 
Crystalline  (lens); 
Vitreous. 

FIRST  TUNIC. — The  Sclerotic  and  Cornea  form  the  external  tunic  of  the 
eyeball,  and  give  it  its  peculiar  form.  Four-fifths  of  the  globe  are  invested 
by  the  sclerotic,  the  remaining  fifth  by  the  cornea. 

The  Sclerotic  (tfxX^og,  hard)  is  a  c'ense  fibrous  membrane,  thicker  behind 
than  in  front.  It  is  continuous,  pos  teriorly,  with  the  sheath  of  the  optic 
nerve,  wrhich  is  derived  from  the  du  ra  mater,  and  is  pierced  by  that  ner"« 
as  well  as  by  the  ciliary  nerves  ai  d  arteries.  Anteriorly  it  presents  a 
bevelled  edge  which  receives  the  c  &mea  in  the  same  way  that  a  watcn- 

•  Conrad  Victor  Schneider,  professor  of:  fedicine  a,.  Wf'tenberg.  His  work,  entitled 
Dt  Catarrhis,  &c.  was  published  in  1  if  J. 

38 


446  STRUCTURE  OF  THE  CORNEA. 

glass  is  received  by  the  groove  in  its  case.  Its  anterior  surface  is  covered 
by  a  thin  tendinous  layer,  the  tunica  albuginea,  derived  from  the  expansion 
of  the  tendons  of  the  four  recti  muscles.  By  its  posterior  surface  it  gives 
attachment  to  the  two  oblique  muscles.  The  tunica  albuginea  is  covered, 
for  a  part  of  its  extent,  by  the  mucous  membrane  of  the  front  of  the  eye, 
the  conjunctiva ;  and,  by  reason  of  the  brilliancy  of  its  whiteness,  gives 
occasion  to  the  common  expression,  "the  white  of  the  eye." 

At  the  entrance  of  the  optic  nerve,  the  sclerotic  forms  a  thin  cribriform 
lamella  (lamina  cribrosa),  which  is  pierced  by  a  number  of  minute  open- 
ings for  the  passage  of  the  nervous  filaments.     One  of  these  openings,  larger 
than  the  rest,  and  situated  in  the  centre  of  the  lamella,  is  the  porus  opticus 
through  which  the  arteria  centralis  retinae  enters  the  eyeball. 

Fig.  199.* 


The  Cornea  (corneus,  horny)  is  the  transparent  projecting  layer  that 
constitutes  the  anterior  fifth  of  the  globe  of  the  eye.  In  its  form  it  is  cir- 
cular, concavo-convex,  and  resembles  a  watch-glass.  It  is  received  by 
its  edge,  which  is  sharp  and  thin,  within  the  bevelled  border  of  the  scle- 
rotic, to  which  it  is  very  firmly  attached,  and  it  is  somewhat  thicker  than 
the  anterior  portion  of  that  tunic.  When  examined  from  the  exterior,  its 
vertical  diameter  is  seen  to  be  about  one-sixteenth  shorter  than  the  trans- 
verse, in  consequence  of  the  overlapping  above  and  below,  of  the  margin 
of  the  sclerotica ;  on  the  interior,  however,  its  outline  is  perfectly  circular. 

The  cornea  is  composed  of  four  layers :  namely,  of  the  conjunctiva;  of 
the  cornea  proper,  which  consists  of  several  thin  lamellae  connected  together 
by  an  extremely  fine  areolar  tissue  ;  of  the  cornea  elastica,  a  "  fine,  elastic, 
and  exquisitely  transparent  membrane,  exactly  applied  to  the  inner  surface 

*  A  longitudinal  section  of  the  globe  of  the  eye.  1.  The  sclerotic,  thicker  behind  than 
in  front.  2.  The  cornea,  received  within  the  anterior  margin  of  the  sclerotic,  and  con- 
nected with  it  by  means  of  a  bevelled  edge.  3.  The  choroid,  connected  anteriorly 
•with  (4)  the  ciliary  ligament,  and  (5)  the  ciliary  processes.  C.  The  iris.  7.  The  pupil. 
8.  The  third  layer  of  the  eye,  the  retina,  terminating  anteriorly  by  an  abrupt  border  at 
the  commencement  of  the  ciliary  processes.  9.  The  canal  of  Petit,  which  encircles  the 
ions  (12)  ;  the  thin  layer  in  front  of  this  canal  is  the  zonula  ciliaris,  a  prolongation  of 
the  vascular  layer  of  the  retina  to  the  lens.  10.  The  anterior  chamber  of  the  eye,  con- 
taining the  aqueous  humour:  the  lining  membrane  by  which  the  humour  is  secreted  is 
represented  in  the  diagram.  11.  The  posterior  chamber.  12.  The  lens,  more  convex 
behind  than  before,  and  enclosed  in  its  proper  capsule.  13.  The  vitreous  humour  en- 
closed in  the  hyaloid  membrane,  and  in  cells  formed  in  its  interior  by  that  membrane. 
14.  A  tubular  sheath  of  the  hyaloid  membrane,  which  serves  for  the  passage  of  the  artery 
>f  the  capsule  of  the  lens,.  15.  The  neurilemma  of  the  optic  nerve.  16.  The  arteria 
rentralis  retinae,  embedded  in  the  centre  of  the  optic  nerve. 


SECOND    TUNIC.  447 

of  the  cornea  proper,"  and  of  the  lining  membrane  of  the  anterior  chamber 
of  the  eyeball  The  cornea  elastica  is  remarkable  for  its  perfect  transpa- 
rency, even  when  submitted  for  many  days  to  the  action  of  water  or  alco- 
hol ;  while  the  cornea  proper  is  rendered  opaque  by  the  same  immersion. 
To  expose  this  membrane,  Dr.  Jacob  suggests  that  the  eye  should  be  placed 
in  water  for  six  or  eight  days,  and,  then,  that  all  the  opaque  cornea  should 
be  removed  layer  after  layer.  Another  character  of  the  cornea  elastica  is 
its  great  elasticity,  which  causes  it  to  roll  up  when  divided  or  torn,  in  the 
same  manner  as  the  capsule  of  the  lens!  The  use  of  this  layer,  according 
to  Dr.  Jacob,  is  to  "  preserve  the  requisite  permanent  correct  curvature 
of  the  flaccid  cornea  proper." 

The  opacity  of  the  cornea,  produced  by  pressure  on  the  globe,  results 
from  the  infiltration  of  fluid  into  the  areolar  tissue  connecting  its  layers. 
This  appearance  cannot  be  produced  in  a  sound  living  eye. 

Dissection. — The  sclerotic  and  cornea  are  now  to  be  dissected  away 
from  the  second  tunic ;  this,  with  care,  may  be  easily  performed,  the  only 
connexions  subsisting  between  them  being  at  the  circumference  of  the  iris, 
the  entrance  of  the  optic  nerve,  and  the  perforation  of  the  ciliary  nerves 
and  arteries.  Pinch  up  a  fold  of  the  sclerotic  near  its  anterior  circumfer- 
ence, and  make  a  small  opening  into  it,  then  raise  the  edge  of  the  tunic, 
and  with  a  pair  of  fine  scissors,  having  a  probe  point,  divide  the  entire 
circumference  of  the  sclerotic,  and  cut  it  away  bit  by  bit.  Then  separate 
it  from  its  attachment  around  the  circumference  of  the  iris  by  a  gentle 
pressure  with  the  edge  of  the  knife.  The  dissection  of  the  eye  must  be 
conducted  under  water. 

In  the  course  of  this  dissection  the  ciliary  nerves  and  long  ciliary  arteries 
will  be  seen  passing  forwards  between  the  sclerotic  and  choroid  to  be  dis- 
tributed to  the  iris. 

SECOND  TUNIC. — The  second  tunic  of  the  eyeball  is  formed  by  the  cho- 
roid, ciliary  ligament,  and  iris,  the  ciliary  processes  being  an  appendage 
developed  from  its  inner  surface. 

The  Choroid*  is  a  vascular  membrane  of  a  rich  chocolate-brown  colour 
upon  its  external  surface,  and  of  a  deep  black  colour  within.  It  is  con- 
nected to  the  sclerotic,  externally,  by  an  extremely  fine  areolar  tissue,  and 
by  nerves  and  vessels.  Internally  it  is  in  simple  contact  with  the  third 
tunic  of  the  eye,  the  retina.  It  is  pierced  posteriorly  for  the  passage  of 
the  optic  nerve,  and  is  connected  anteriorly  with  the  iris,  ciliary  processes, 
and  with  the  line  of  junction  of  the  cornea  and  sclerotic,  by  a  dense  white 
structure,  the  ciliary  ligament,  which  surrounds  the  circumference  of  the 
iris  like  a  ring. 

The  choroid  membrane  is  composed  of  three  layers : — an  external  or 
venous  layer,  which  consists  principally  of  veins  arranged  in  a  peculiar 
manner :  hence  they  have  been  named  ventz  vorticoste.  The  marking  on 

*  The  word  choroid  has  been  very  much  abused  in  anatomical  language ;  it  was  origi- 
nally applied  to  the  membrane  of  the  foetus  called  chorion  from  the  Greek  word  Copier, 
domicilium,  that  membrane  being,  as  it  were,  the  abode  or  receptacle  of  the  fetus 
Xdpiov  conues  from  £<op«o,  to  take  or  receive.  Now  it  so  happens  that  the  chorion  in 
the  ovum  is  a  vascular  membrane  of  peculiar  structure.  Hence  the  term  choroid, 
%6pu>v  n8oj,  like  the  chorion,  has  been  used  indiscriminately  to  signify  vascular  structures, 
as  in  the  choroid  membrane  of  the  eye,  the  choroid  plexus,  &c.,  and  we  find  Cruveil- 
hier  in  his  work  on  Jlnatomy,  vol.  iii.  p.  403,  saying  in  a  note,  "  Choroide  est  synonyme 
de  vascuk-use." 


443 


CILIARY    LIGAMENT — IRIS. 


Fig.  200.* 


the  surface  of  the  membrane  pro- 
duced by  these  veins  resembles  so 
many  centres  to  which  a  number  of 
curved  lines  converge.  It  is  this 
layer  which  is  connected  with  the 
ciliary  ligament.  The  middle  or  ar- 
terial layer  (tunica  Ruyschiana^}  is 
5  formed  principally  by  the  ramifica- 
tions of  minute  arteries.  It  is  re- 
flected inwards  at  its  junction  with 
the  ciliary  ligament,  so  as  to  form 
the  ciliary  processes.  The  internal 
layer  is  a  delicate  membrane  (mem- 
brana  pigmenti]  composed  of  seve- 
ral laminae  of  nucleated  hexagonal 
cells,  which  contain  the  granules  of  pigmentum  nigrum,  and  are  arranged 
so  as  to  resemble  a  tesselated  pavement. 

In  animals,  the  pigmentum  nigrum,  on  the  posterior  wall  of  the  eyeball, 
is  replaced  by  a  layer  of  considerable  extent,  and  of  metallic  brilliancy, 
called  the  tapetum. 

The  Ciliary  ligament,  or  circle,  is  the  bond  of  union  between  the  ex- 
ternal and  middle  tunics  of  the  eyeball,  and  serves  to  connect  the  cornea 
and  sclerotic,  at  their  line  of  junction,  with  the  iris  and  external  layer  of 
the  choroid.  It  is  also  the  point  to  which  the  ciliary  nerves  and  vessels 
proceed  previously  to  their  distribution,  and  it  receives  the  anterior  ciliary 
arteries  through  the  anterior  margin  of  the  sclerotic.  A  minute  vascular 
canal  is  situated  within  the  ciliary  ligament,  called  the  ciliary  canal,  or  the 
canal  of  Fontana,|  from  its  discoverer. 

The  Iris  (iris,  a  rainbow,)  is  so  named  from  its  variety  of  colour  in  dif- 
ferent individuals :  it  forms  a  septum  between  the  anterior  and  posterior 
chambers  of  the  eye,  and  is  pierced  somewhat  to  the  nasal  side  of  its  centre 
by  a  circular  opening,  which  is  called  the  pupil.  By  its  periphery  it  is 
connected  with  the  ciliary  ligament,  and  by  its  inner  circumference  forms 
the  margin  of  the  pupil ;  its  anterior  surface  looks  towards  the  cornea,  and 
the  posterior  towards  the  ciliary  processes  and  lens. 

The  iris  is  composed  of  two  layers,  an  anterior  or  muscular,  consisting 
of  radiating  fibres  which  converge  from  the  circumference  towards  the 
centre,  and  have  the  power  of  dilating  the  pupil ;  and  circular,  which  sur- 
round the  pupil  like  a  sphincter,  and  by  their  action  produce  contraction 

*  A  dissection  of  the  eyeball,  showing  its  second  tunic,  and  the  mode  of  distribution 
of  the  venae  vorticosae  of  the  choroid.  After  Arnold.  1.  Part  of  the  sclerotic  coat.  2. 
The  optic  nerve.  3,  3.  The  choroid  coat.  4.  The  ciliary  ligament.  5.  The  iris.  6,  6. 
The  vense  vorticosse.  7,  7.  The  trunks  of  the  venae  vorticosae  at  the  point  where  they 
have  pierced  the  sclerotica.  8,  8.  The  posterior  ciliary  veins,  which  enter  the  eyeball 
n  company  with  the  posterior  ciliary  arteries,  by  piercing  the  sclerotic  at  9.  10.  One 
of  the  long  ciliary  nerves,  accompanied  by  a  long  ciliary  vein. 

|  Ruysch  was  born  at  the  Hague  in  1638,  and  was  appointed  professor  of  Anatomy 
at  Amsterdam  in  1665.  His  whole  life  was  employed  in  making  injected  preparations, 
for  which  he  is  justly  celebrated,  and  he  died  at  the  advanced  age  of  ninety-three  years. 
He  came  to  the  conclusion  that  the  body  was  entirely  made  up  of  vessels. 

t  Felix  Fontana,  an  anatomist  of  Tuscany.  His  "  Description  of  a  New  Canal  in  th« 
five  "  was  published  in  1778,  in  a  Letter  to  the  Professor  of  Anati  my  in  Upsal. 


THIRD    TUNIC. 


449 


of  its  area.  The  posterior  layer  is  of  a  deep  purple  tint,  and  is  thence 
named  uvea,  from  its  resemblance  in  colour  to  a  ripe  grape. 

The  Ciliary  processes  may  be  seen  in  two  ways,  either  by  removing  the 
iris  from  its  attachment  to  the  ciliary  ligament,  when  a  front  view  of  the 
processes  will  be  obtained,  or  by  making  a  transverse  section  through  the 
globe  of  the  eye,  when  they  may  be  examined  from  behind,  as  in  f^g.  201. 

The  ciliary  processes  consist  of  a  number  of  triangular  folds,  formed 
apparently  by  the  plaiting  of  the  middle  and  internal  layer  of  the  choroid. 
According  to  Zinn,  they  are  about  sixty  in  number,  and  may  be  divided 
into  large  and  small,  the  latter  being  situated  in  the  spaces  between  the 
former.  Their  periphery  is  connected  with  the  ciliary  ligament,  and  is 
continuous  with  the  middle  and  internal  layer  of  the  choroid.  The  central 
border  is  free,  and  rests  against  the  circumference  of  the  lens.  The  ante- 
rior surface  corresponds  with  the  uvea ;  the  posterior  receives  the  folds  of 
the  zonula  ciliaris  between  its  processes,  and  thus  establishes  a  connexion 
between  the  choroid  and  the  third  tunic  of  the  eye.  The  ciliary  processes 
are  covered  with  a  thick  layer  of  pigmentum  nigrum,  which  is  more 
abundant  upon  them,  and  upon  the  anterior  part  of  the  choroid,  than  upon 
the  posterior  part.  When  the  pigment  is  washed  off,  the  processes  are  of 
a  whitish  colour. 


Fig.  201* 


Fig.  202.f 


THIRD  TUNIC.  —  The  third  tunic  of  the  eye  is  the  retina,  which  is  pro* 
longed  forwards  to  the  lens  by  the  zonula  ciliaris. 

Dissection.  —  If,  after  the  preceding  dissection,  the  choroid  membrane 
be  carefully  raised  and  removed,  the  eye  being  kept  under  water,  the 
retina  may  be  seen  very  distinctly. 

*The  anterior  segment  of  a  transverse  section  of  the  globe  of  the  eye,  seen  from 
within.  1.  The  divided  edge  of  the  three  tunics;  sclerotic,  choroid  (the  dark  layer), 
and  retina.  2.  The  pupil.  3.  The  iris,  the  surface  presented  to  view  in  this  section 
being  the  uvea.  4.  The  ciliary  processes.  5.  The  scalloped  anterior  border  of  the 
retina. 

f  The  posterior  segment  of  a  transverse  section  of  the  globe  of  the  eye,  seen  from 
within.  1.  The  divided  edge  of  the  three  tunics.  The  membrane  covering  the  whole 
internal  surface  is  the  retina.  2.  The  entrance  of  the  optic  nerve  with  the  arteria  cen- 
tialis  retina;  piercing  its  centre.  3,  3.  The  ramifications  of  the  arteria  centralis.  4.  Th« 
foramen  of  Soemmering,  in  tli3  centre  of  the  axis  of  the  eye;  the  shade  from  the  sidei 
of  the  section  obscures  the  limbus  luteus  which  surrounds  it.  5.  A  fold  of  the  retina 
which  generally  obscures  the  foramen  of  Soemmering  after  the  eye  has  been  opened 
38*  2D 


450  .        RETINA — STRUCTURE. 

The  Retina  is  composed  of  three  layers : — 

External,  or  Jacob's  membrane, 
Middle,         Nervous  membrane, 
Internal,        Vascular  membrane. 

Jacob's  membrane  is  extremely  thin,  and  is  seen  as  a  mere  film  when 
the  freshly  dissected  eye  is  suspended  in  water.  Examined  by  the  micro- 
scope, it  is  found  to  be  composed  of  cells  having  a  tesselated  arrangement. 
Dr.  Jacob  considers  it  to  be  a  serous  membrane. 

The  Nervous  membrane  is  the  expansion  of  the  optic  nerve,  and  forms 
a  thin  semi-transparent  bluish-white  layer,  which  envelopes  the  vitreous 
humour,  and  extends  forwards  to  the  commencement  of  the  ciliary  pro- 
cesses, where  it  terminates  by  an  abrupt  scalloped  margin.  According  to 
Treviranus,  this  layer  is  composed  of  cylindrical  fibres,  which  proceed 
from  the  optic  nerve,  and,  near  their  termination,  bend  abruptly  inwards, 
to  form  the  internal  papillary  layer,  which  lies  in  contact  with  the  hyaloid 
membrane ;  each  fibre  constituting  by  its  extremity  a  distinct  papilla. 

The  Vascular  membrane  consists  of  the  ramifications  of  a  minute  artery, 
the  arteria  centralis  retinae,  and  its  accompanying  vein  ;  the  artery  pierces 
the  optic  nerve,  and  enters  the  globe  of  the  eye  through  the  porus  opticus, 
in  the  centre  of  the  lamina  cribrosa.  This  artery  may  be  seen  very  dis- 
tinctly by  making  a  transverse  section  of  the  eyeball.  Its  branches  are 
continued  anteriorly  into  the  zonula  ciliaris.  The  vascular  layer  forms 
distinct  sheaths  for  the  nervous  papillae,  which  constitute  the  inner  surface 
of  the  retina. 

In  the  centre  of  the  posterior  part  of  the  globe  of  the  eye  the  retina  pre- 
sents a  circular  spot,  which  is  called  the  foramen  of  Soemmenng  ;*  it  is 
surrounded  by  a  yellow  halo,  the  limbus  luteus,  and  is  frequently  obscured 
by  an  elliptical  fold  of  the  retina,  which  has  been  regarded  as  a  normal 
condition  of  the  membrane.  The  term  foramen  is  misapplied  to  this  spot, 
for  the  vascular  layer  and  the  membrana  Jacobi  are  continued  across  it ; 
the  nervous  substance  alone  appearing  to  be  deficient.  It  exists  only  in 
animals  having  the  axes  of  the  eyeballs  parallel  with  each  other,  as  man, 
quadrumana,  and  some  saurian  reptiles,  and  is  said  to  give  passage  to  a 
small  lymphatic  vessel. 

The  Zonula  ciliaris  (zonula  of  Zinn)f  is  a  thin  vascular  layer,  which 
connects  the  anterior  margin  of  the  retina  with  the  anterior  surface  of  the 
lens  near  its  circumference.  It  presents  upon  its  surface  a  number  of 
small  folds  corresponding  with  the  ciliary  processes,  between  which  they 
are  received.  These  processes  are  arranged  in  the  form  of  rays  around 
the  lens,  and  the  spaces  between  them  are  stained  by  the  pigmentum 
nigrum  of  the  ciliary  processes.  They  derive  their  vessels  from  the  vas- 
cular layer  of  the  retina.  The  under  surface  of  the  zonula  is  in  contact 
with  the  hyaloid  membrane,  and  around  the  lens  forms  the  anterior  fluted 
wall  of  the  canal  of  Petit. 

*  Samuel  Thomas  Soemmering  is  celebrated  for  the  beautiful  and  accurate  plates 
winch  accompany  his  works.  The  account  "  De  Foramine  Centrali  Retinas  Humanse, 
Limbo  Luteo  cincto,"  was  published  in  1779,  in  the  Commentationes  Soc.  Reg.  Scient. 
Gottingensis. 

f  John  Gottfried  Zinn,  professor  of  Anatomy  in  Gottingen;  his  "Descriptio  Anatomicn 
Oculi  Humani"  was  published  in  1755,  with  excellent  plates.  It  was  republished  by 
Wrisberg  in  1780. 


HUMOURS.  451 

The  connexion  between  these  folds  and  the  ciliary  processes  may  be 
very  easily  demonstrated  by  dividing  an  eye  transversely  into  two  por- 
tions, then  raising  the  anterior  half,  and  allowing  the  vitreous  humour  to 
separate  from  its  attachment  by  its  own  weight.  The  folds  of  the  zonula 
will  then  be  seen  to  be  drawn  out  from  between  the  folds  of  the  ciliary 
processes. 

HUMOURS. — The  Aqueous  humour  is  situated  in  the  anterior  and  poste- 
rior chambers  of  the  eye;  it  is  a  weakly  albuminous  fluid,  havino-  an  alka- 
line reaction,  and  a  specific  gravity  very  little  greater  than  that  of  distilled 
water.  According  to  Petit,  it  scarcely  exceeds  four  or  five  grains  in 
weight. 

The  anterior  chamber  is  the  space  intervening  between  the  cornea  in 
front,  and  the  iris  and  pupil  behind.  The  posterior  chamber  is  the  narrow 
space,  less  than  half  a  line  in  depth,*  bounded  by  the  posterior  surface  of 
the  iris  and  pupil  in  front,  and  by  the  ciliary  processes,  zonula  ciliaris, 
and  lens  behind.  The  two  chambers  are  lined  by  a  thin  layer,  the  secret- 
ing membrane  of  the  aqueous  humour. 

The  Vitreous  humour  forms  the  principal  bulk  of  the  globe  of  the  eye. 
It  is  an  albuminous  and  highly  transparent  fluid,  enclosed  in  a  delicate 
membrane,  the  hyaloid.  From  the  inner  surface  of  this  membrane,  nu- 
merous thin  lamellae  are  directed  inwards,  and  form  compartments  in 
which  the  fluid  is  contained.  According  to  Hannover,  these  lamella?  have 
a  radiated  arrangement,  like  those  on  the  transverse  section  of  an  orange, 
and  are  about  180  in  number.  In  the  centre  of  the  vitreous  humour  is  a 
tubular  canal,  through  which  a  minute  artery  is  conducted  from  the  arteria 
centralis  retinae  to  the  capsule  of  the  lens.  This  vessel  is  injected  without 
difficulty  in  the  fo2tus. 

The  Crystalline  humour  or  lens  is  situated  immediately  behind  the  pu- 
pil, and  is  surrounded  by  the  ciliary  processes,  which  slightly  overlap  its 
margin.  It  is  more  convex  on  the  posterior  than  on  the  anterior  surface, 
and  is  embedded  in  the  anterior  part  of  the  vitreous  humour,  from  which 
it  is  separated  by  the  hyaloid  membrane.  It  is  invested  by  a  peculiarly 
transparent  and  elastic  membrane,  the  capsule  of  the  lens,  which  contains 
a  small  quantity  of  fluid,  called  liquor  Morgagni,\  and  is  retained  in  its 
place  by  the  attachment  of  the  zonula  ciliaris.  Dr.  Jacob  is  of  opinion 
that  the  lens  is  connected  to  its  capsule  by  means  of  areolar  tissue,  and 
that  the  liquor  Morgagni  is  the  result  of  a  cadaveric  change. 

The  lens  consists  of  concentric  layers,  of  which  the  external  are  soft, 
the  next  firmer,  and  the  central  form  a  hardened  nucleus.  These  layers 
are  best  demonstrated  by  boiling,  or  by  immersion  in  alcohol,  when  they 
separate  easily  from  each  other.  Another  division  of  the  lens  takes  place 
at  the  same  time :  it  splits  into  three  triangular  segments,  which  have  the 
sharp  edge  directed  towards  the  centre,  and  the  base  towards  the  circum- 
ference. The  concentric  lamellae  are  composed  of  minute  parallel  fibres, 
which  are  united  with  each  other  by  means  of  scalloped  borders,  the  con- 

*  Winslow  and  Lieutaud  thought  the  iris  to  be  in  contact  with  the  lens ;  it  frequently 
adheres  to  the  capsule  of  the  latter  in  iritis.  The  depth  of  the  posterior  chamber  if 
greater  in  old  tlian  in  young  persons. 

f  John  Baptist  Morgagni  was  born  in  1682.  He  was  appointed  Professor- ^>f  Medi 
cine  in  Bologna,  and  published  the  first  part  of  his  "Adversaria  Anatomiea  '  u:  t70« 
He  died  in  1771. 


452  ARTERIA    CENTRALIS    RETINAE. 

7exity  on  the  one  border  fitting  accurately  the  concave  scallop  upon  the 
other. 

Immediately  around  the  circumference  of  the  lens  is  a  triangular  canal, 
the  canal  of  Petit  *  about  a  line  and  a  half  in  breadth.  It  is  bounded,  in 
front,  by  the  flutings  of  the  zonula  ciliaris  ;  behind,  by  the  hyaloid  mem- 
brane ;  and,  within,  by  the  border  of  the  lens. 

The  Vessels  of  the  globe  of  the  eye  are  the  long  and  short,  and  anterior 
ciliary  arteries,  and  the  arteria  centralis  retinaB.  The  long  ciliary  arteries, 
two  in  number,  pierce  the  posterior  part  of  the  sclerotic,  and  pass  forward 
on  each  side,  between  that  membrane  and  the  choroid,  to  the  ciliary  liga- 
ment, where  they  divide  into  two  branches,  which  are  distributed  to  the 
iris.  The  short  ciliary  arteries  pierce  the  posterior  part  of  the  sclerotic 
coat,  and  are  distributed  to  the  middle  layer  of  the  choroid  membrane. 
The  anterior  ciliary  are  branches  of  the  muscular  arteries.  They  enter 
the  eye  through  the  anterior  part  of  the  sclerotic,  and  are  distributed  to 
the  iris.  It  is  the  increased  number  of  these  latter  arteries,  in  iritis,  that 
gives  rise  to  the  peculiar  red  zone  around  the  circumference  of  the  cornea 
which  accompanies  that  disease. 

The  arteria  centralis  retinte  enters  the  optic  nerve  at  about  half  an  inch 
from  the  globe  of  the  eye,  and  passing  through  the  poms  opticus  is  distri- 
buted upon  the  inner  surface  of  the  retina,  forming  its  vascular  layer ;  one 
branch  pierces  the  centre  of  the  vitreous  humour,  and  supplies  the  capsule 
of  the  lens. 

The  Nerves  of  the  eyeball  are,  the  optic,  two  ciliary  nerves  from  the 
nasal  branch  of  the  ophthalmic,  and  the  ciliary  nerves  from  the  ciliary 
ganglion. 

Observations.  —  The  sclerotic  is  a  tunic  of  protection,  and  the  cornea  a 
medium  for  the  transmission  of  light.  The  choroid  supports  the  vessels 
destined  for  the  nutrition  of  the  eye,  and  by  its  pigmentum  nigrum  absorbs 
all  loose  and  scattered  rays  that  might  confuse  the  image  impressed  upon 
the  retina.  The  iris,  by  means  of  its  powers  of  expansion  and  contraction, 
regulates  the  quantity  of  light  admitted  through  the  pupil.  If  the  iris  be 
thin,  and  the  rays  of  light  pass  through  its  substance,  they  are  immediately 
absorbed  by  the  uvea ;  and  if  that  layer  be  insufficient,  they  are  taken  up 
by  the  black  pigment  of  the  ciliary  processes.  In  Albinoes,  where  there 
is  an  absence  of  pigmentum  nigrum,  the  rays  of  light  traverse  the  iris,  and 
even  the  sclerotic,  and  so  overwhelm  the  eye  with  light,  that  sight  is  de- 
stroyed, except  in  the  dimness  of  evening  or  at  night.  In  the  manufacture 
of  optical  instruments  care  is  taken  to  colour  their  interior  black  with  the 
same  object,  the  absorption  of  scattered  rays. 

The  transparent  lamellated  cornea  and  the  humours  of  the  eye  have  for 
their  office  the  refraction  of  the  rays  in  such  proportion  as  to  direct  the 
image  in  the  most  favourable  manner  upon  the  retina.  Where  the  refract- 
ing medium  is  too  great,  as  in  over  convexity  of  the  cornea  and  lens,  the 
image  falls  short  of  the  retina  (myopia,  near-sightedness) ;  and  where  it  is 
too  little,  the  image  is  thrown  beyond  the  nervous  membrane  (presbyopia, 
far-sightedness).  These  conditions  are  rectified  by  the  use  of  spectacles, 
which  provide  a  differently  refracting  medium  externally  to  the  eye,  and 
thereby  correct  the  transmission  of  light. 

John  Louis  Petit,  a  celebrated  French  surgeon :  he  published  several  surgical  and 
anatomical  Essays,  in  the  early  part  of  the  18th  century.  He  died  in  1750. 


EYEBROWS EYELIDS.  453 


APPENDAGES    OF     THE     EYE. 

The  Appendages  of  the  Eye  (tutamina  oculi)  are,  the  eyebrows,  eye 
lids,  eyelashes,  conjunctiva,  caruncula  lachrymalis,  and  the  lachrymal  ap- 
paratus. 

The  Eyebrows  (supercilia)  are  two  projecting  arches  of  integument 
covered  with  short  thick  hairs,  which  form  the  upper  boundary  of  the 
orbits.  They  are  connected  beneath  with  the  orbiculares,  occipito-fron- 
tales,  and  corrugatores  superciliorum  muscles ;  their  use  is  to  shade  the 
eyes  from  too  vivid  a  light,  or  protect  them  from  particles  of  dust  and 
moisture  floating  over  the  forehead. 

The  Eyelids  (palpebra)  are  two  valvular  Fig.  203.* 

layers  placed  in  front  of  the  eye,  serving  to 
defend  it  from  injury  by  their  closure.  When 
drawn  open,  they  leave  between  them  an  ellip- 
tical space,  the  angles  of  which  are  called 
canthi.  The  outer  canthus  is  formed  by  the 
meeting  of  the  two  lids  at  an  acute  angle. 
The  inner  canthus  is  prolonged  for  a  short 
distance  inwards  towards  the  nose,  and  a 
triangular  space  is  left  between  the  lids  in  this 
situation,  which  is  called  the  lacus  lachrymalis. 
At  the  commencement  of  the  lacus  lachrymalis 
upon  each  of  the  two  lids  is  a  small  angular 

projection,  the  lachrymal  papilla  or  tubercle ;  and  at  the  apex  of  each 
papilla  a  small  orifice  (punctum  lachrymale),  the  commencement  of  the 
lachrymal  canal. 

The  eyelids  have,  entering  into  their  structure,  integument,  orbicularis 
muscle,  tarsal  cartilages,  Meibomian  glands,  and  conjunctiva. 

The  tegumentary  areolar  tissue  of  the  eyelids  is  remarkable  for  its  loose- 
ness and  for  the  absence  of  adipose  substance ;  it  is  particularly  liable  to 
serous  infiltration.  The  fibres  of  the  orbicularis  muscle  covering  the  eye- 
lids, are  extremely  thin  and  pale. 

The  Tarsal  cartilages  are  two  thin  lamellae  of  fibro-cartilage  about  an 
inch  in  length,  which  give  form  and  support  to  the  eyelids.  The  superior 
is  of  a  semilunar  form,  about  one-third  of  an  inch  in  breadth  at  its  middle, 
and  tapering  to  each  extremity.  Its  lower  border  is  broad  and  flat,  its 
upper  is  thin,  and  gives  attachment  to  the  levator  palpebrse  and  to  the 
fibrous  membrane  of  the  lids. 

The  Inferior  fibro-cartilage  is  an  elliptical  band,  narrower  than  the  su- 
perior, and  situated  in  the  substance  of  the  lower  lid.  Its  upper  border 
is  flat,  and  corresponds  with  the  flat  edge  of  the  upper  cartilage.  The 
lower  is  held  in  its  place  by  the  fibrous  membrane.  Near  the  inner  can- 
thus  the  tarsal  cartilages  terminate,  at  the  commencement  of  the  lacus  lach 

*  The  appendages  of  the  eye.  1.  The  superior  tarsal  cartilage.  2.  The  lower  border 
of  the  cartilage  on  which  are  seen  the  openings  of  the  Meibomian  glands.  3.  The  infe 
rior  tarsal  cartilage  ;  along  the  upper  border  of  this  cartilage  the  openings  of  the  Meibo- 
mian glands  are  likewise  seen.  4.  The  lachrymal  gland  ;  its  superior  or  orbital  portion. 
5.  Its  inferior  or  palpebral  portion.  6.  The  lachrymal  ducts.  7.  The  plica  semilunaris.. 
8.  The  caruncula  lachrymalis.  9.  The  puncta  lachrymalia  of  the  lachrymal  canals 
10.  The  superior  lachrymal  canal.  11.  The  inferior  lachrymal  canal.  12.  T'ie  lachry 
m:>l  sac.  14.  The  dilatation  of  the  nasal  duct,  where  it  opens  into  the  inferior  meatni 
of  the  nose.  15.  The  nasal  duct. 


454  MEIBOMIAN    GLANDS. 

rymahs,  and  are  attached  to  the  margin  of  the  orbit  by  the  tenao  oculi. 
At  their  outer  extremity  they  terminate  at  a  short  distance  from  the  angle 
of  the  canthus,  and  are  retained  in  their  position  by  means  of  a  decussa- 
tion  of  the  fibrous  structure  of  the  broad  tarsal  ligament,  called  the  external 
palpebral  ligament. 

The  Fibrous  membrane  of  the  lids  is  firmly  attached  to  the  periosteum, 
around  the  margin  of  the  orbit,  by  its  circumference,  and  to  the  tarsal 
cartilages  by  its  central  margin.  It  is  thick  and  dense  on  the  outer  half 
of  the  orbit,  but  becomes  thin  to  its  inner  side.  Its  use  is  to  retain  the 
tarsal  cartilages  in  their  place,  and  give  support  to  the  lids ;  hence  it  has 
been  named  the  broad  tarsal  ligament. 

The  Meibomian  glands*  are  embedded  in  the  internal  surface  of  the 
cartilages,  and  are  very  distinctly  seen  on  examining  the  inner  aspect  of 
the  lids.  They  have  the  appearance  of  parallel  strings  of  pearls,  about 
thirty  in  number  in  the  upper  cartilage,  and  somewhat  fewer  in  the  lower ; 
and  open  by  minute  foramina  on  the  edges  of  the  lids.  They  correspond 
in  length  with  the  breadth  of  the  cartilage,  and  are  consequently  longer 
in  the  upper  than  in  the  lower  lid. 

Each  gland  consists  of  a  single  lengthened  follicle  or  tube,  into  which 
a  number  of  small  clustered  follicles  open ;  the  latter  are  so  numerous  as 
almost  to  conceal  the  tube  by  which  the  secretion  is  poured  out  upon  the 
margin  of  the  lids.  Occasionally  an  arch  is  formed  between  two  of  them, 
and  produces  a  very  graceful  appearance. 

The  edges  of  the  eyelids  are  furnished  with  a  triple  row  of  long  thick 
hairs,  which  curve  upwards  from  the  upper  lid,  and  downwards  from  the 
lower,  so  that  they  may  not  interlace  with  each  other  in  the  closure  of  the 
eyelids,  and  prove  an  impediment  to  the  opening  of  the  eyes.  These  are 
the  eyelashes  (cilia),  important  organs  of  defence  to  the  sensitive  surface 
of  so  delicate  an  organ  as  the  eye. 

The  Conjunctiva  is  the  mucous  membrane  of  the  eye.  It  covers  the 
whole  of  its  anterior  surface,  and  is  then  reflected  upon  the  lids  so  as  to 
form  their  internal  layer.  The  duplicatures  formed  between  the  globe  of 
the  eye  and  the  lids  are  called  the  superior  and  inferior  palpebral  sinuses, 
of  which  the  former  is  much  deeper  than  the  inferior.  Where  it  covers 
the  cornea  the  conjunctiva  is  very  thin  and  closely  adherent,  and  no  ves- 
sels can  be  traced  into  it.  Upon  the  sclerotica  it  is  thicker  and  less  ad- 
herent, but  upon  the  inner  surface  of  the  lids  is  very  closely  connected, 
and  exceedingly  vascular.  v  It  is  continuous  with  the  general  gastro-pul- 
monary  mucous  membrane  and  sympathises  in  its  affections,  as  may  be 
observed  iiK  various  diseases.  From  the  surface  of  the  eye  it  may  be 
traced  through  the  lachrymal  ducts  into  the  lachrymal  gland  ;  along  the 
edges  of  the  lids  it  is  continuous  with  the  mucous  lining  of  the  Meibomiau 
glands,  and  at  the  inner  angle  of  the  eye  may  be  followed  through  the 
lachrymal  canals  into  the  lachrymal  sac,  and  thence  downwards  through 
the  nasal  duct  into  the  inferior  meatus  of  the  nose. 

The  Caruncula  lachrymalis  is  the  small  reddish  body  which  occupies 
the  lacus  lachrymalis  at  the  inner  canthus  of  the  eye.  In  health  it  presents 
»  bright  pink  tint ;  in  sickness  it  loses  its  colour  and  becomes  pale.  It 
consists  of  an  assemblage  of  follicles  similar  to  the  Meibomian  glands, 
embedded  in  a  fibro-cartilaginous  tissue,  and  is  the  source  of  the  whitish 
secretion  which  so  constantly  forms  at  the  inner  angle  of  the  eye.  It  is 

*  Henry  Meibomius,  lide  Vasis  Palpebrarum  Novis,"  1666. 


LACHRYMAL    APPARATUS.  455 

covered  with  minute  hairs  which  are  sometimes  so  long  as  to  be  distinctly 
visible  to  the  naked  eye. 

Immediately  to  the  outer  side  of  the  caruncula  is  a  slight  duplicature 
of  the  conjunctiva,  called  plica  semilunaris,  which  contains  a  minute  plate 
of  cartilage,  and  is  the  rudiment  .of  the  third  lid  of  animals,  the  membrana 
nictitans  of  birds. 

Vessels  and  Nerves. — The  palpebrse  are  supplied  internally  with  arteries 
from  the  ophthalmic,  and  externally  from  the  facial  and  transverse  facial. 
Their  nerves  are  branches  of  the  fifth  and  of  the  facial. 


LACHRYMAL    APPARATUS. 

The  Lachrymal  apparatus  consists  of  the  lachrymal  gland  with  its  ex- 
cretory ducts  ;  the  puncta  lachrymalia,  and  lachrymal  canals ;  the  lachry- 
mal sac  and  nasal  duct. 

The  Lachrymal  gland  is  situated  at  the  upper  and  outer  angle  of  the 
orbit,  and  consists  of  two  portions,  orbital  and  palpebral.  The  orbital 
portion,  about  three-quarters  of  an  inch  in  length,  is  flattened  and  oval  in 
shape,  and  occupies  the  lachrymal  fossa  in  the  orbital  plate  of  the  frontal 
bone.  It  is  in  contact  superiorly  with  the  periosteum,  with  which  it  is 
closely  connected  by  its  upper  and  convex  surface ;  by  its  inferior  or  con- 
cave surface  it  is  in  relation  with  the  globe  of  the  eye,  and  the  superior 
and  external  rectus ;  and  by  its  anterior  border  with  the  broad  tarsal  liga- 
ment. By  its  posterior  border  it  receives  its  vessels  and  nerves.  The 
palpebral  portion,  smaller  than  the  preceding,  is  situated  in  the  upper 
eyelid,  extending  downwards  to  the  superior  margin  of  the  tarsal  cartilage. 
It  is  continuous  with  the  orbital  portion  above,  and  is  enclosed  in  an  in- 
vestment of  dense  fibrous  membrane.  The  secretion  of  the  lachrymal 
gland  is  conveyed  away  by  from  eight  to  twelve  small  ducts,  which  run 
for  a  short  distance  beneath  the  conjunctiva,  and  open  upon  its  surface 
by  a  series  of  pores  about  one-twentieth  of  an  inch  apart,  situated  in  a 
curved  line  a  little  above  the  upper  border  of  the  tarsal  cartilage. 

Lachrymal  Canals.  —  The  lachrymal  canals  commence  at  the  minute 
openings,  puncta  lachrymalia,  seen  upon  the  lachrymal  papillae  of  the  lids 
at  the  outer  extremity  of  the  lacus  lachrymalis,  and  proceed  inwards  to  the 
lachrymal  sac,  where  they  terminate  beneath  a  valvular  semilunar  fold  of 
the  lining  membrane  of  the  sac.  The  superior  duct  at  first  ascends,  and 
then  turns  suddenly  inwards  towards  the  sac,  forming  an  abrupt  angle. 
The  inferior  duct  forms  the  same  kind  of  angle,  by  descending  at  first,  and 
then  turning  abruptly  inwards.  They  are  dense  and  elastic  in  structure, 
and  remain  constantly  open,  so  that  they  act  like  capillary  tubes  in  ab- 
sorbing the  tears  from  the  surface  of  the  eye.  The  two  fasciculi  of  the 
tensor  tarsi  muscle  are  inserted  into  these  ducts,  and  serve  to  draw  them 
inwards. 

The  Lachrymal  sac  is  the  upper  extremity  of  the  nasal  duct,  and  is 
scarcely  more  dilated  than  the  rest  of  the  canal.  It  is  lodged  in  the 
groove  of  the  lachrymal  bone,  and  is  often  distinguished,  internally,  from 
the  nasal  duct,  by  a  semilunar  or  circular  valve.  The  sac  consists  of 
mucous  membrane,  but  is  covered  in  and  retained  in  its  place  by  a  fibrous 
expansion,  derived  from  the  tendon  of  the  oroicularis,  which  is  inserted 
into  the  ridge  on  the  lachrymal  bone ;  it  'S  also  covered  by  the  tensor  tarsi 


456  ORGAN    OF    HEARING. 

muscle,  which  arises  from  the  same  ridge,  and  in  its  action  upon  the 
lachrymal  canals  may  serve  to  compress  the  lachrymal  sac. 

The  Nasal  duct  is  a  short  canal  about  three-quarters  of  an  inch  in 
length,  directed  downwards,  backwards,  and  a  little  outwards  to  the  infe- 
rior meatus  of  the  nose,  where  it  terminates  by  an  expanded  orifice.  It 
is  lined  by  mucous  membrane,  which  is  continuous  with  the  conjunctiva 
above,  and  with  the  pituitary  membrane  of  the  nose  below.  Obstruction, 
from  inflammation  and  suppuration  of  this  duct,  constitutes  the  disease 
called  fistula  lachrymalis. 

Vessels  and  Nerves.  —  The  lachrymal  gland  is  supplied  with  blood  by 
the  lachrymal  branch  of  the  ophthalmic  artery,  and  with  nerves  by  the 
lachrymal  branch  of  the  ophthalmic  and  orbital  branch  of  the  superior 
maxillary. 

THE   ORGAN   OF  HEARING. 

The  apparatus  of  hearing  is  composed  of  three  parts ;  the  external  ear, 
middle  ear  or  tympanum,  and  internal  ear  or  labyrinth. 

The  EXTERNAL  EAR  consists  of  two  portions,  the  pinna  and  meatus ;  the 
former  representing  a  kind  of  funnel  which  collects  the  vibrations  of  the 
atmosphere,  producing  sounds,  and  the  latter  a  tube  which  conveys  the 
vibrations  to  the  tympanum. 

The  PINNA  presents  a  number  of  holes  and  hollows  upon  its  surface, 
which  have  different  names  assigned  to  them.  Thus,  the  external  folded 
margin  is  called  the  helix  (eXif,  a  fold).  The  elevation  parallel  to  and  in 
front  of  the  helix  is  called  antihelix  (dvri,  opposite).  The  pointed  process, 
projecting  like  a  valve  over  the  opening  of  the  ear  from  the  face,  is  called 
the  tragus  (-r^ayoc;,  a  goat),  probably  from  being  sometimes  covered  with 
bristly  hair  like  that  of  a  goat ;  and  a  tubercle  opposite  to  this  is  the  anti- 
tragus.  The  lower  dependent  and  fleshy  portion  of  the  pinna  is  the 
lobulus.  The  space  between  the  helix  and  antihelix  is  named  the  fossa 
innominata.  Another  depression  is  observed  at  the  upper  extremity  of 
the  antihelix,  which  bifurcates  and  leaves  a  triangular  space  between  its 
branches,  called  the  scaphoid  fossa ;  and  the  large  central  space,  to  wThich 
all  the  channels  converge,  is  the  concha,  which  opens  directly  into  the 
meatus. 

The  pinna  is  composed  of  integument,  fibro-cartilage,  ligaments,  and 
muscles. 

The  Integument  is  thin,  contains  an  abundance  of  sebiparous  glands, 
and  is  closely  connected  with  the  fibro-cartilage. 

The  Fibro-cartilage  gives  form  to  the  pinna,  and  is  folded  so  as  to  pro- 
duce the  various  convexities  and  grooves  which  have  been  described  upon 
its  surface.  The  helix  commences  in  the  concha,  and  partially  divides 
that  cavity  into  two  parts ;  on  its  anterior  border  is  a  tubercle  for  the 
attachment  of  the  attrahens  aurem  muscle,  and  a  little  above  this  a  small 
vertical  fissure,  the  fissure  of  the  helix.  The  termination  of  the  helix  and 
antihelix  forms  a  lengthened  process,  the  processus  caudatus,  which  is 
separated  from  the  concha  by  an  extensive  fissure.  Upon  the  anterior 
surface  of  the  tragus  is  another  fissure,  the  fissure  of  the  tragus,  and  in 
the  lobulus  the  fibro-cartilage  is  wholly  deficient.  The  fibro-cartilage  of 
the  meatus,  at  the  upper  and  anterior  part  of  the  cylinder,  is  divided  from 


MEATUS    AUDITORIUS.  457 

(he  concha  by  a  fissure  which  is  closed  in  the  entire  ear  by  ligamentous 
fibres ;  it  is  firmly  attached  at  its  termination  to  the  processus  auditorius. 

The  Ligaments  of  the  external  ear  are  those  which  attach  the  pinna  to 
the  side  of  the  head,  viz.  the  anterior,  posterior,  and  ligament  of  the 
tragus ;  and  those  of  the  fibro-cartilage,  which  serve  to  preserve  its  folds 
and  connect  the  opposite  margins  of  the  fissures.  The  latter  are  two  in 
number,  the  ligament  between  the  concha  and  the  processus  caudatus,  and 
the  broad  ligament  which  extends  from  the  upper  margin  of  the  fibro-car- 
tilage of  the  tragus  to  the  helix,  and  completes  the  meatus. 

The  proper  Muscles  of  the  pinna  are  the — 

Major  helicis, 
Minor  helicis, 
Tragicus, 
Antitragicus, 
Transversus  auriculae. 

The  Major  helicis  is  a  narrow  band  of  muscular  fibres  situated  upon  the 
anterior  border  of  the  helix,  just  above  the  tragus. 

The  Minor  helicis  is  placed  upon  the  posterior  border  of  the  helix,  at 
its  commencement  in  the  fossa  of  the  concha. 

The  Tragicus  is  a  thin  quadrilateral  layer  of  muscular  fibres,  situated 
upon  the  tragus. 

The  Antitragicus  arises  from  the  antitragus,  and  is  inserted  into  the 
posterior  extremity,  or  processus  caudatus  of  the  helix. 

The  Transversus  auricula,  partly  tendinous  and  partly  muscular,  ex- 
tends transversely  from  the  convexity  of  the  concha  to  that  of  the  helix, 
on  the  posterior  surface  of  the  pinna. 

These  muscles  are  rudimentary  in  the  human  ear,  and  deserve  only  the 
title  of  muscles  in  the  ears  of  animals.  Two  other  muscles  are  described 
by  Mr.  Tod,*  the  obliquus  auris  and  contractor  meatus,  or  trago-helicus. 

The  MEATUS  AUDITORIUS  is  a  canal,  partly  cartilaginous  and  partly  os- 
seous, about  an  inch  in  length,  which  extends  inwards  and  a  little  forwards 
from  the  concha  to  the  tympanum.  It  is  narrower  in  the  middle  than  at 
each  extremity,  forms  an  oval  cylinder,  the  long  diameter  being  vertical, 
and  is  slightly  curved  upon  itself,  the  concavity  looking  downwards. 

It  is  lined  by  an  extremely  thin  pouch  of  epithelium,  which,  when  with- 
drawn after  maceration,  preserves  the  form  of  the  meatus.  Some  stiff 
short  hairs  are  also  found  in  its  interior,  which  stretch  across  the  tube,  and 
prevent  the  ingress  of  insects  and  dust.  In  the  substance  of  its  lining 
membrane  are  a  number  of  ceruminous  glands,  which  secrete  the  wax  of 
the  ear. 

Vessels  and  Nerves. — The  pinna  is  plentifully  supplied  with  arteries ; 
by  the  anterior  auricular  from  the  temporal,  and  by  the  posterior  auricular 
from  the  external  carotid. 

Its  Nerves  are  derived  from  the  anterior  auricular  of  the  fifth,  the  pos- 
terior auricular  of  the  facial,  and  the  auricularis  magnus  of  the  cervical 
plexus. 

»  "The  Anatomy  and  Physiology  of  the  Organ  of  Hearing,"  by  David  Tod,  1832 

39 


458 


TYMPANUM. 


Fig.  204." 


MIDDLE     EAR     OR     TYMPANUM. 

The  tympanum  is  an  irregular  bony  cavity,  compressed  from  without 
inwards,  and  situated  within  the  petrous  bone.  It  is  bounded,  externally, 
by  the  meatus  and  membrana  tympani ;  internally ',  by  the  base  of  the  pe- 
trous bone  ;  behind,  by  the  mastoid  cells ;  and,  throughout  the  rest  of  its 
circumference,  by  the  thin  osseous  layer  which  connects  the  petrous  with 
the  squamous  portion  of  the  temporal  bone. 

The  Membrana  tympani  is  a  thin 
and  semi-transparent  membrane  of 
an  oval  shape,  its  long  diameter  be- 
ing vertical.  It  is  inserted  into  a 
groove  situated  around  the  circum- 
ference of  the  meatus,  near  its  termi- 
nation, and  is  placed  obliquely  across 
the  area  of  that  tube,  the  direction 
of  the  obliquity  being  downwards 
and  inwards.  It  is  concave  towards 
the  meatus,  and  convex  towards  the 
tympanum,  and  is  composed  of  three 
layers,  an  external,  epidermal ;  mid- 
dle, fibrous  and  muscular ;  and,  in- 
ternal, mucous,  derived  from  the 
mucous  lining  of  the  tympanum. 

The  tympanum  contains  three 
small  bones,  ossicula  auditus,  viz., 
the  malleus,  incus,  and  stapes. 

The  Malleus  (hammer)  consists  of 
a  head,  neck,  handle  (manubrium), 

and  two  processes,  long  (processus  gracilis),  and  short  (processus  brevis}. 
The  manubrium  is  connected  with  the  membrana  tympani  by  its  whole 
length,  extending  below  the  central  point  of  that  membrane.  It  lies  be- 
neath the  mucous  layer  of  the  membrane,  and  serves  as  a  point  of  attach- 
ment to  which  the  radiating  fibres  of  the  fibrous  layer  converge.  The  long 
process  descends  to  a  groove  near  the  fissura  Glaseri,  and  gives  attachment 
to  the  laxator  tympani  muscle.  Into  the  short  process  is  inserted  the  ten- 
don of  the  tensor  tympani,  and  the  head  of  the  bone  articulates  with  the 
incus. 

The  Incus  (anvil)  is  named  from  an  imagined  resemblance  to  an  anvil. 
It  has  also  been  likened  to  a  bicuspid  tooth,  having  one  root  longer  than, 

*  A  diagram  of  the  ear.  p.  The  pinna,  t.  The  tympanum.  1.  The  labyrinth.  1. 
The  upper  part  of  the  helix.  2.  The  antihelix.  3.  The  tragus.  4.  The  antitragus.  5. 
The  lobulus.  6.  The  concha.  7.  The  upper  part  of  the  fossa  innominata.  8.  The 
meatus.  9.  The  membrana  tympani,  divided  by  the  section.  10.  The  three  little  bones, 
crossing  the  area  of  the  tympanum,  malleus,  incus,  and  stapes;  the  foot  of  the  stapes 
blocks  up  the  fenestra  ovalis  upon  the  inner  wall  of  the  tympanum.  11.  The  promon- 
tory. 12.  The  fenestra  rotunda;  the  dark  opening  above  the  ossicula  leads  into  trie 
mastoid  cells.  13.  The  Eustachian  tube;  the  little  canal  upon  this  tube  contains  the 
tensor  tympani  muscle  in  its  passage  to  the  tympanum.  14.  The  vestibule.  15.  The 
three  semi-circular  canals,  horizontal,  perpendicular,  and  oblique.  16.  The  ampulla 
upon  the  perpendicular  and  horizontal  canals.  17.  The  cochlea.  18.  A  depression  be- 
tween the  convexities  of  the  two  tubuli  which  communicate  with  the  tympanum  suid 
vestibule :  the  one  is  the  scala  tympani,  terminating  at  12 ;  the  other  is  the  scola 
vrstibuli. 


MUSCLES    OF    THE    TYMPANUM.  459 

and  widely  separated  from,  the  other.  It  consists  of  two  processes,  which 
unite  nearly  at  right  angles,  and  at  their  junction  form  a  flattened  body, 
which  articulates  with  the  head  of  the  malleus.  The  short  process  is  at 
tached  to  the  margin  of  the  opening  of  the  mastoid  cells  by  means  of  a 
ligament ;  the  long  process  descends  nearly  parallel  with  the  handle  of  the 
malleus,  and  curves  inwards,  near  its  termination.  At  its  extremity  is  a 
small  globular  projection  the  os  orbiculare,  which  in  the  fetus  is  a  distinct 
bone,  but  becomes  anchylosed  to  the  long  process  of  the  incus  in  the 
adult ;  this  process  articulates  with  the  head  of  the  stapes. 

The  Stapes  is  shaped  like  a  stirrup,  to  which  it  bears  a  close  resemblance. 
Its  head  articulates  with  the  os  orbiculare,  and  the  two  branches  are  con- 
nected by  their  extremities  with  a  flat,  oval-shaped  plate,  representing  the 
foot  of  the  stirrup.  The  foot  of  the  stirrup  is  received  into  the  fenestra 
ovalis,  to  the  margin  of  which  it  is  connected  by  means  of  a  circular  liga- 
ment ;  it  is  in  contact,  by  its  surface,  with  the  membrana  vestibuli,  and  is 
covered  in  by  the  mucous  lining  of  the  tympanum.  The  neck  of  the  stapes 
gives  attachment  to  the  stapedius  muscle. 

The  ossicula  auditus  are  retained  in  their  position  and  moved  upon 
themselves  by  means  of  ligaments  and  muscles. 

The  Ligaments  are  three  in  number ;  the  ligament  of  the  head  of  the 
malleus,  which  is  attached  to  the  upper  wall  of  the  tympanum ;  the  liga- 
ment of  the  incus,  a  short  and  thick  band,  which  serves  to  attach  the  ex- 
tremity of  the  short  process  of  that  bone  to  the  margin  of  the  opening  of  the 
mastoid  cells ;  and  the  circular  ligament  which  connects  the  margin  of  the 
foot  of  the  stapes  with  the  circumference  of  the  fenestra  ovalis.  These 
ligaments  have  been  described  as  muscles,  by  Mr.  Tod,  under  the  names 
of  superior  capitis  mallei,  obliquus  incudis  externus  posterior,  and  mus- 
culus  vel  structura  stapedii  inferior. 

The  Muscles  of  the  tympanum  are  four  in  number,  the — 

Tensor  tympani, 
Laxator  tympani, 
Laxator  tympani  minor, 
Stapedius. 

The  Tensor  tympani  (musculus  internus  mallei)  arises  from  the  spinous 
process  of  the  sphenoid,  from  the  petrous  portion  of  the  temporal  bone, 
and  from  the  Eustachian  tube,  and  passes  forwards  in  a  distinct  canal, 
separated  from  the  tube  by  the  processus  cochleariformis,  to  be  inserted 
into  the  handle  of  the  malleus,  immediately  below  the  commencement  of 
the  processus  gracilis. 

The  Laxator  tympani  (musculus  externus  mallei)  arises  from  the  spinous 
process  of  the  sphenoid  bone,  and  passes  through  an  opening  in  the  fissura 
Glaseri,  to  be  inserted  into  the  long  process  of  the  malleus.  This  is  re- 
garded as  a  ligament  by  some  anatomists. 

The  Laxator  tympani  minor  arises  from  the  upper  margin  of  the  meatus, 
and  is  inserted  into  the  handle  of  the  malleus,  near  the  processus  brevis, 
This  is  regarded  as  a  ligament  by  some  anatomists. 

The  Stapedius  arises  from  the  interior  of  the  pyramid,  and  escapes  from 
its  summit  to  be  inserted  into  the  neck  of  the  stapes. 


460  FORAMINA    OF    THE    TYMPANUM. 

Foramina.  —The  openings  in  the  tympanum  are  ten  in  number,  Jive 
large  and  Jive  small;  they  are — 

Large  Openings.  Small  Openings. 

Meatus  auditorius,  Entrance  of  the  chorda  tympani, 

Fenestra  ovalis,  Exit  of  the  chorda  tympani, 

Fenestra  rotunda,  For  the  laxator  tympani, 

Mastoid  cells,  For  the  tensor  tympani, 

Eustachian  tube.  For  the  stapedius. 

The  opening  of  the  meatus  auditorius  has  been  already  described. 

The  Fenestra  ovalis  (fenestra  vestibuli),  is  a  reniform  opening,  situated 
at  the  bottom  of  a  small  oval  fossa  (the  pelvis  ovalis),  in  the  upper  part 
of  the  inner  wall  of  the  tympanum,  directly  opposite  the  meatus.  The 
long  diameter  of  the  fenestra  is  directed  horizontally,  and  its  convex 
borders  upwards.  It  is  the  opening  of  communication  between  the  tym- 
panum and  vestibule,  and  is  closed  by  the  foot  of  the  stapes  and  by  the 
lining  membranes  of  both  cavities. 

The  Fenestra  rotunda  (fenestra  cochleae)  is  somewhat  triangular  in  its  form, 
and  situated  in  the  inner  wall  of  the  tympanum,  below  and  rather  poste- 
riorly to  the  fenestra  ovalis,  from  which  it  is  separated  by  a  bony  elevation, 
called  the  promontory.  It  serves  to  establish  a  communication  between 
the  tympanum  and  the  cochlea.  In  the  fresh  subject  it  is  closed  by  a 
proper  membrane  (m.  tympani  secundaria,)  as  well  as  by  the  lining  of 
both  cavities. 

The  Mastoid  cells  are  numerous,  and  occupy  the  whole  of  the  interior 
of  the  mastoid  process  and  part  of  the  petrous  bone.  They  communicate 
by  a  large  irregular  opening  with  the  upper  and  posterior  circumference 
of  the  tympanum. 

The  'Eustachian  tube  is  a  canal  of  communication  extending  obliquely 
between  the  pharynx  and  the  anterior  circumference  of  the  tympanum.  In 
structure  it  is  partly  fibro-cartilaginous  and  partly  osseous,  is  broad  and 
expanded  at  its  pharyngeal  extremity,  and  narrow  and  compressed  at  the 
tympanum. 

The  smaller  openings  serve  for  the  transmission  of  the  chorda  tympani 
nerve,  and  three  of  the  muscles  of  the  tympanum. 

The  opening  by  which  the  chorda  tympani  enters  the  tympanum,  is  at 
about  the  middle  of  its  posterior  wall,  and  near  the  root  of  the  pyramid 

The  opening  of  exit  for  the  chorda  tympani  is  at  the  fissure  Glaseri  in 
the  anterior  wall  of  the  tympanum. 

The  opening  for  the  laxator  tympani  muscle  is  also  situated  in  the  fissura 
Glaseri,  in  the  anterior  wall  of  the  tympanum. 

The  opening  for  the  tensor  tympani  muscle  is  in  the  inner  wall,  imme- 
diately above  the  opening  of  the  Eustachian  tube. 

The  opening  for  the  stapedius  muscle  is  at  the  apex  of  a  conical  bony 
eminence,  called  the  pyramid,  which  is  situated  on  the  posterior  wall  of 
the  tympanum,  immediately  behind  the  fenestra  ovalis. 

Directly  above  the  fenestra  ovalis  is  a  rounded  ridge  formed  by  the  pro- 
jection of  the  aquceductus  Fallopii. 

Beneath  the  fenestra  ovalis  and  separating  it  from  the  fenestra  rotunda 
Ls  the  promontory,  a  rounded  prominence  formed  by  the  projection  of  the 


INTERNAL  EAR LABYRINTH.  461 

first  turn  of  the  cochlea.     It  is  channelled  upon  its  surface  by  three  small 
grooves,  which  lodge  the  three  tympanic  branches  of  Jacobson's  nerve. 

The  Foramina  and  processes  of  the  tympanum  may  be  arranged  accord- 
.ng  to  their  situation,  into  four  groups. 

1.  In  the  External  wall  is  the  meatus  auditorius,  closed  by  the  mem- 
brana  tympani. 

2.  In  the  Inner  wall,  from  above  downwards,  are  the — 

Opening  for  the  tensor  tympani, 

Ridge  of  the  aquseductus  Fallopii, 

Fenestra  ovalis, 

Promontory, 

Grooves  for  Jacobson's  nerve, 

Fenestra  rotunda. 

3.  In  the  Posterior  wall  are  the — 

Opening  of  the  mastoid  cells, 

Pyramid, 

Opening  for  the  stapedius, 

Opening  for  Jacobson's  nerve, 

Apertura  chordae  (entrance). 

4    In  the  Anterior  wall  are  the — 

Eustachian  tube, 
Fissura  Glaseri, 

Opening  for  the  laxator  tympani, 
'    Apertura  chordae  (exit). 

The  tympanum  is  lined  by  a  vascular  mucous  membrane,  which  invests 
the  ossicula  and  chorda  tympani,  and  forms  the  internal  layer  of  the  mem- 
brana  tympani.  From  the  tympanum  it  is  reflected  into  the  mastoid  cells, 
which  it  lines  throughout,  and  it  passes  through  the  Eustachian  tube  to 
become  continuous  with  the  mucous  membrane  of  the  pharynx. 

Vessels  and  Nerves.  —  The  Arteries  of  the  tympanum  are  derived  from 
the  internal  maxillary,  internal  carotid,  and  posterior  auricular. 

Its  JVerves  are, — 1.  Minute  branches  from  the  facial,  which  are  distri- 
buted to  the  stapedius  muscle.  2.  The  chorda  tympani,  which  leaves  the 
facial  nerve  near  the  stylo-mastoid  foramen,  and  arches  upwards  to  enter 
the  tympanum  at  the  root  of  the  pyramid ;  it  then  passes  forwards  between 
the  handle  of  the  malleus  and  long  process  of  the  incus,  to  its  proper 
opening  in  the  fissura  Glaseri.  3.  The  tympanic  branches  of  Jacobsorfs 
nerve,  which  are  distributed  to  the  membranes  of  the  fenestra  ovalis  and 
fenestra  rotunda,  and  to  the  Eustachian  tube,  and  form  a  plexus  by  com- 
municating with  the  carotid  plexus,  otic  ganglion,  and  Vidian  nerve.  4. 
A  filament  from  the  otic  ganglion  to  the  tensor  tympani  muscle. 

INTERNAL    EAR. 

The  Internal  ear  is  called  labyrinth,  from  the  complexity  of  its  commu- 
nications ;  it  consists  of  a  membranous  and  an  osseous  portion.     The 
39* 


462  VESTIBULE. 

osseous  labyrinth  presents  a  series  of  cavities,  which  are  channelled  through 
the  substance  of  the  petrous  bone,  and  is  situated  between  the  cavity  of 
the  tympanum  and  the  meatus  auditorius  internus.     It  is  divisible  into 
the—- 
Vestibule, 

Semicircular  canals, 
Cochlea. 

The  VESTIBULE  is  a  small  three-cornered  cavity,  compressed  from  with- 
out inwards,  and  situated  immediately  within  the  inner  wall  of  the  tym- 
panum. The  three  corners,  which  are  named  ventricles  or  cornua,  are 
placed,  one  anteriorly,  one  superiorly,  and  one  posteriorly. 

The  anterior  ventricle  receives  the  oval  aperture  of  the  scala  vestibuli ; 
the  superior,  the  ampullary  openings  of  the  superior  and  horizontal  semi- 
circular canals ;  the  posterior,  the  ampullary  opening  of  the  oblique  semi- 
circular canal,  the  common  aperture  of  the  oblique  and  perpendicular 
canals,  the  termination  of  the  horizontal  canal,  and  the  aperture  of  the 
aquaeductus  vestibuli.  In  the  anterior  ventricle  is  a  small  depression, 
which  corresponds  with  the  posterior  segment  of  the  cul  de  sac  of  the 
meatus  auditorius  internus ;  it  is  called  the  fovea  hemispherica,  and  is 
pierced  by  a  cluster  of  small  openings,  the  macula  cribrosa.  In  the  supe- 
rior ventricle  of  the  vestibule  is  another  small  depression,  the  fovea  ellip- 
tica,  which  is  separated  from  the  fovea  hemispherica  by  a  projecting  crest, 
the  eminentia  pyramidalis.  The  latter  is  pierced  by  numerous  minute 
openings  for  the  passage  of  nervous  filaments.  The  posterior  ventricle 
presents  a  third  small  depression,  the  fovea  sulciformis,  which  leads  up- 
wards to  the  ostium  aqueeductus  vestibuli.  The  internal  wall  of  the  ves- 
tibule corresponds  with  the  bottom  of  the  cul  de  sac  of  the  meatus  audito- 
rius internus,  and  is  pierced  by  numerous  small  openings  for  the  transmis- 
sion of  nervous  filaments.  In  the  external  or  tympanic  wall  is  the  reniform 
opening  of  the  fenestra  ovalis  (fenestra  vestibuli),  the  margin  of  which 
presents  a  prominent  rim  towards  the  cavity  of  the  vestibule. 

The  openings  of  the  vestibule  may  be  arranged,  like  those  of  the  tym- 
panum, into  large  and  small. 

The  Large  openings  are  seven  in  number :  viz.  the — 

Fenestra  ovalis, 
Scala  vestibuli, 
Five  openings  of  the  three  semicircular  canals. 

The  Small  openings  are  the — 

Aquseductus  vestibuli, 

Openings  for  small  arteries, 

Openings  for  branches  of  the  auditory  nerve. 

The  Fenestra  ovalis  has  already  been  described ;  it  is  the  opening  from 
the  tympanum. 

The  opening  of  the  scala  vestibuli  is  the  oval  termination  of  the  vestibu- 
ar  canal  of  the  cochlea. 

The  Aqueeductus  vestibuli  (canal  of  Cotunnius)  is  the  commencement 
of  the  small  canal  which  opens  under  the  osseous  scale  upon  the  posterior 
surface  of  the  petrous  bone.  It  gives  passage  to  a  process  of  membrane 


SEMICIRCULAR    CANALS COCHLEA.  463 

(which  is  continuous  internally  with  the  lining  membrane  of  the  vestibule, 
and  externally  with  the  dura  mater),  and  to  a  small  vein. 

The  Openings  for  arteiies  and  nerves  are  situated  in  the  internal  wall  of 
the  vestibule,  and  correspond  with  the  termination  of  the  meatus  audito- 
rius  internus. 

The  SEMICIRCULAR  CANALS  are  three  bony  passages  communicatino1 
with  the  vestibule,  into  which  they  open  by  both  extremities.  Near  one 
extremity  of  each  of  the  canals  is  a  remarkable  dilatation  of  its  cavity, 
which  is  called  the  ampulla  (sinus  ampullaceus).  The  superior,  or  per- 
pendicular canal  (canalis  semicircularis  verticalis  superior),  is  directed 
transversely  across  the  petrous  bone,  forming  a  projection  on  the  anterior 
face  of  the  latter.  It  commences,  by  means  of  an  ampulla,  in  the  supe- 
rior ventricle  of  the  vestibule,  and  terminates  posteriorly  by  joining  with 
the  oblique,  and  forming  a  common  canal,  which  opens  into  the  upper 
part  of  the  posterior  ventricle.  The  middle  or  oblique  canal  (canalis  semi- 
circularis verticalis  posterior)  corresponds  with  the  posterior  part  of  the 
petrous  portion  of  the  temporal  bone :  it  commences  by  an  ampullary  di- 
latation in  the  posterior  ventricle,  and  curves  nearly  perpendicularly  up- 
wards to  terminate  in  the  common  canal.  In  the  ampulla  of  this  canal 
are  numerous  minute  openings  for  nervous  filaments.  The  inferior  or 
horizontal  canal  (canalis  semicircularis  horizontalis)  is  directed  outwards 
towards  the  base  of  the  petrous  bone,  and  is  shorter  than  the  two  preced- 
ing. It  commences  by  an  ampullary  dilatation  in  the  superior  ventricle, 
and  terminates  in  the  posterior  ventricle. 

The  COCHLEA  (snail-shell]  forms  the  anterior  portion  of  the  labyrinth, 
corresponding  by  its  apex  with  the  anterior  wall  of  the  petrous  bone,  and 
by  its  base  with  the  anterior  depression  at  the  bottom  of  the  cul  de  sac  of 
the  meatus  auditorius  internus.  It  consists  of  an  osseous  and  gradually 
tapering  canal,  about  one  inch  and  a  half  in  length,  which  makes  two 
turns  and  a  half  spirally  around  a  central  axis,  called  the  modiolus. 

The  central  axis,  or  modiolus,  is  large  near  its  base,  where  it  corre- 
sponds with  the  first  turn  of  the  cochlea,  and  diminishes  in  diameter  to- 
wards its  extremity.  At  its  base,  it  is  pierced  by  numerous  minute  open- 
ings, which  transmit  the  filaments  of  the  cochlear  nerve.  These  openings 
are  disposed  in  a  spiral  manner :  hence  they  have  received,  from  Cotun- 
nius,*  the  name  of  tractus  spiralis  foraminulentus.  The  modiolus  is  every- 
where traversed,  in  the  direction  of  its  length,  by  minute  canals,  which 
proceed  from  the  tractus  spiralis  foraminulentus,  and  terminate  upon  the 
sides  of  the  modiolus,  by  opening  into  the  canal  of  the  cochlea  or  upon 
the  surface  of  its  lamina  spiralis.  The  central  canal  of  the  tractus  spiralis 
foraminulentus  is  larger  than  the  rest,  and  is  named  the  tubulus  centralis 
modioli ;  it  is  continued  onwards  to  the  extremity  of  the  modiolus,  and 
transmits  a  nerve  and  small  artery  (arteria  centralis  modioli). 

The  interior  of  the  canal  of  the  cochlea  is  partially  divided  into  two 
passages  (scalae)  by  means  of  a  thin  and  porous  lamina  of  bone  (zonula 
ossea  laminae  spiralis),  which  is  wound  spirally  around  the  modiolus  in 
the  direction  of  the  canal.     This  bony  septum  extends  for  about  two 
Iliirds  across  the  diameter  of  the  canal,  and  in  the  fresh  subject,  is  pro 

*  Dominieo  Cotunnius.  an  Italian  physician;  hi?  dissertation  "  De  Aqutecluctibu* 
Auris  Humanae  Internae"  was  published  at  Naples  in  1761. 


464 


COCHLEA MODIOLUS. 


Fig.  205.»  longed  to  the  opposite  wall  by  means  of  a 

membranous  layer,  so  as  to  constitute  a 
complete   partition,   the   lamina  spiralis. 
The  osseous  lamina  spiralis  consists  of  two 
thin  lamellae  of  bone,  between  which,  and 
through  the  perforations  on  their  surfaces, 
the  filaments  of  the  cochlear  nerve  reach 
the  membrane  of  the  cochlea.  At  the  apex 
of  the  cochlea  the  lamina  spiralis  terminates 
by  a  pointed,  hook-shaped  process,  the 
hamulus  lamina?  spiralis.     The  two  scalae 
of  the  cochlea,  which  are  completely  sepa- 
rated throughout  their  length  in  the  living  ear,  communicate  superiorly, 
over  the  hamulus  lamina?  spiralis,  by  means  of  an  opening  common  to 
both,  which  has  been  termed  by  Breschet  helico- 
trema  (s'Xig,  £Xi'<r<rw  volvere — T^a).     Inferiorly, 
one  of  the  two  scalae,  the  scala  vestibuli,  termi- 
nates by  means  of  an  oval  aperture  in  the  ante- 
rior ventricle  of  the  vestibule ;  while  the  other, 
the  scala  tympani,  becomes  somewhat  expand- 
ed, and  opens  into  the  tympanum  through  the 
fenestra  rotunda  (fenestra  cochlea?).     Near  the 
termination  of  the  scala  tympani  is  the  small 
opening  of  the  aquaeductus  cochlea?. 

The  internal  surface  of  the  osseous  labyrinth 
'3  is  lined  by  a  fibro-serous  membrane,  which  is 
analogous  to  the  dura  mater  in  performing  the 
office  of  a  periosteum  by  its  exterior,  whilst  it 
fulfils  the  purpose  of  a  serous  membrane  by  its 
internal  layer,  secreting  a  limpid  fluid,  the  aqua 

*  The  cochlea  divided  parallel  with  its  axis,  through  the  centre  of  the  modiolus 
After  Breschet.  1.  The  modiolus.  2.  The  infundibulum  in  which  the  modiolus  termi- 
nates. 3,  3.  The  cochlear  nerve,  sending  its  filaments  through  the  centre  of  the  modio- 
lus. 4,  4.  The  scala  tympani  of  the  first  turn  of  the  cochlea.  5,  5.  The  scala  vestibuh 
of  the  first  turn  ;  the  septum  between  4  and  5  is  the  lamina  spiralis ;  a  filament  of  the 
cochlear  nerve  is  seen  passing  between  the  layers  of  the  lamina  to  be  distributed  upon 
the  membrane  which  invests  the  lamina.  8.  Loops  formed  by  the  filaments  of  tho 
cochlear  nerve  on  the  lamina  spiralis.  9,  9.  Scala  tympani  of  the  second  turn  of  the 
cochlea.  10,  10.  Scala  vestibuli  of  the  second  turn  ;  the  septum  between  the,  two  is  the 
lamina  spiralis.  11.  The  remaining  half  turn  of  the  scala  vestibuli;  the  dome  placed 
over  this  half  turn  is  the  cupola  ;  a  line  leads  from  the  numeral  to  the  remaining  half 
turn  of  the  scala  tympani.  The  lamina  of  bone  which  forms  the  floor  of  the  scala  ves- 
tibuli curves  spirally  round  to  constitute  the  infundibulum  (2).  14.  The  helicotrema 
through  which  a  bristle  is  passed ;  its  lower  extremity  issues  from  the  scala  tympani  of 
the  middle  turn  of  the  cochlea.  The  hamulus  lamina  spiralis  is  seen  in  front  of  the 
bristle. 

•j-  The  labyrinth  of  the  left  ear,  laid  open,  in  order  to  show  its  cavities  and  the  mem- 
branous labyrinth.  After  Breschet.  1.  The  cavity  of  the  vestibule,  opened  from  its 
anterior  aspect  in  order  to  show  the  three-cornered  form  of  its  interior,  and  the  mem- 
branous labyrinth  which  it  contains.  The  figure  rests  upon  the  common  saccule  of  the 
membranous  labyrinth, —  the  sacculus  on m munis.  2.  The  ampulla  of  the  superior  or 
perpendicular  semicircular  cant.?,  receiving  a  nervous  fasciculus  from  the  superior 
branch  of  the  vestibular  nerve,  3.  4.  The  superior  or  perpendicular  canal  with  its 
contained  membranous  canal.  5.  The  ampulla  of  the  inferior  or  horizontal  semicircular 
canal,  receiving  a  nervous  fasciculus  from  the  superior  branch  of  the  vestibular  nerve. 
f>.  The  termination  of  the  membranous  canal  of  the  horizontal  semicircular  canal  in  the 
ttucculus  communis.  7.  The  ampulla  of  the  middle  or  obHque  semicircular  canal, 


MEMBRANOUS    LABYRINTH. 

labyrinth!  (liquor  Cotunnii),  and  sending  a  reflection  inwards  upon  the 
nerves  distributed  to  the  membranous  labyrinth.  In  the  cochlea  the  mem- 
brane of  the  labyrinth  invests  the  two  surfaces  of  the  bony  lamina  spiralis, 
and  being  continued  from  its  border  across  the  diameter  of  the  canal  to  its 
outer  wall,  forms  the  membranous  lamina  spiralis,  and  completes  the  se- 
paration between  the  scala  tympani  and  scala  vestibuli.  The  fenestra 
ovalis  and  fenestra  rotunda  are  closed  by  an  extension  of  this  membrane 
across  them,  assisted  by  the  membrane  of  the  tympanum  and  a  proper  in- 
termediate layer.  Besides  lining  the  interior  of  the  osseous  cavity,  the 
membrane  of  the  labyrinth  sends  two  delicate  processes  along  the  aque- 
ducts of  the  vestibule  and  cochlea  to  the  internal  surface  of  the  dura  mater, 
with  which  they  are  continuous.  These  processes  are  the  remains  of  a 
communication  originally  subsisting  between  the  dura  mater  and  the  cavity 
of  the  labyrinth.* 

The  MEMBRANOUS  LABYRINTH  is  smaller  in  size,  but  a  perfect  counter- 
part with  respect  to  form,  of  the  vestibule  and  semicircular  canals.  It 
consists  of  a  small  elongated  sac,  sacculus  communis  (utriculus  communis)  ; 
of  three  semicircular  membranous  canals,  which  correspond  with  the  os- 
seous canals,  and  communicate  with  the  sacculus  communis ;  and  of  a 
small  round  sac  (sacculus  proprius),  which  occupies  the  anterior  ventricle 
of  the  vestibule,  and  lies  in  close  contact  writh  the  external  surface  of  the 
sacculus  communis.  The  membranous  semicircular  canals  are  two-thirds 
smaller  in  diameter  than  the  osseous  canals. 

The  membranous  labyrinth  is  retained  in  its  position  by  means  of  the 
numerous  nervous  filaments  which  are  distributed  to  it  from  the  openings 
in  the  inner  wall  of  the  vestibule,  and  is  separated  from  the  lining  mem- 
brane of  the  labyrinth  by  the  aqua  labyrinthi.  In  structure  it  is  composed 

receiving  a  nervous  fasciculus  from  the  inferior  branch  of  the  vestibular  nerve.  8.  The 
oblique  semicircular  canal  with  its  membranous  canal.  9.  The  common  canal,  resulting 
from  the  union  of  the  perpendicular  with  the  oblique  semicircular  canal.  10.  The  mem- 
branous common  canal  terminating  in  the  sacculus  communis.  11.  The  otoconite  of  the 
sacculus  communis  seen  through  the  membranous  parietes  of  that  sac.  A  nervous  fasci- 
culus from  the  inferior  branch  of  the  vestibular  nerve  is  seen  to  be  distributee!  to  the 
sacculus  communis  near  the  otoconite.  The  extremity  of  the  sacculus  above  the  otoconite 
is  lodged  in  the  superior  ventricle  of  the  vestibule,  and  that  below  it  in  the  inferior  ven- 
tricle. 12.  The  sacculus  proprius  situated  in  the  anterior  ventricle ;  its  otoconite  is  seen 
through  its  membranous  parietes,  and  a  nervous  fasciculus  derived  from  the  middle 
branch  of  the  vestibular  nerve  is  distributed  to  it.  The  spaces  around  the  membranous 
labyrinth  are  occupied  by  the  aqua  labyrinthi.  13.  The  first  turn  of  the  cochlea;  the 
figure  points  to  the  scala  tympani.  14.  The  extremity  of  the  scala  tympani  correspond- 
ing with  the  fenestra  rotunda.  15.  The  lamina  spiralis;  the  figure  is  situated  in  the 
scala  vestibuli.  16.  The  opening  of  the  scala  vestibuli  into  the  vestibule.  17.  The 
second  turn  of  the  cochlea;  the  figure  is  placed  upon  the  lamina  spiralis,  and  therefore 
in  the  scala  vestibuli,  the  scala  tympani  being  beneath  the  lamina.  18.  The  remaining 
half  turn  of  the  cochlea;  the  figure  is  placed  in  the  scala  tympani.  19.  The  lamina 
spiralis  terminating  in  its  falciform  extremity.  The  dark  space  included  within  the 
falciform  curve  of  the  extremity  of  the  lamina  spiralis  is  the  helicotrema.  20.  The  in 
fundibulum. 

*  Cotunnius  regarded  these  processes  as  tubular  canals,  through  which  the  superabuili 
dant  aqua  labyrinthi  might  be  expelled  into  the  cavity  of  the  cranium.  Mr.  Whartort 
Jones,  in  the  article  "  Organ  of  Hearing,"  in  the  Cyclopaedia  of  Anatomy  and  Physiology, 
also  describes  them  as  tubular  canals  which  terminate  beneath  the  dura  mater  of  the 
petrous  bone  in  a  small  dilated  pouch.  In  the  ear  of  a  man,  deaf  and  dumb  from  bJrtli, 
he  found  the  termination  of  the  aqueduct  of  the  vestibule  of  unusually  large  size  in  con 
•equence  of  irregular  development. 

2E 


466  DISTRIBUTION    OF    THE    AUDITORY    NERVE. 

of  four  layers ;  an  external  or  serous  layer,  derived  from  the  lining  mem- 
brane of  the  labyrinth  ;  a  vascular  layer,  in  which  an  abundance  of  minute 
vessels  are  distributed ;  a  nervous  layer,  formed  by  the  expansion  of  the 
filaments  of  the  vestibular  nerve  ;  and  an  internal  and  serous  membrane, 
by  which  the  limpid  fluid  which  fills  its  interior  is  secreted.  Some  patches 
of  pigment  have  been  observed  by  Mr.  "Wharton  Jones  in  the  tissue  of  the 
membranous  labyrinth  of  man.  Among  animals  such  spots  are  constant. 

The  membranous  labyrinth  is  filled  with  a  limpid  fluid,  first  w  11  de- 
scribed by  Scarpa,  and  thence  named  liquor  Scarpae  (endolymph,*  vitreous 
humour  of  the  ear),  and  contains  two  small  calcareous  masses,  called 
otoconites.  The  otoconites  (oSV,  w<rog,  xovij,  the  ear-dust)  consist  of  an 
assemblage  of  minute,  crystalline  particles  of  carbonate  and  phosphate  of 
lime,  held  together  by  animal  substance,  and  probably  retained  in  form  by 
a  reflection  of  the  lining  membrane  of  the  membranous  labyrinth.  They 
are  found  suspended  in  the  liquor  Scarpse  ;  one  in  the  sacculus  communis, 
the  other  in  the  sacculus  proprius,  from  that  part  of  each  sac  with  which 
the  nerves  are  connected. 

The  AUDITORY  NERVE  divides  into  two  branches  at  the  bottom  of  the 
cul  de  sac  of  the  meatus  auditorius  internus ;  a  vestibular  nerve  and  a 
cochlear  nerve.  The  vestibular  nerve,  the  most  posterior  of  the  two,  divides 
into  three  branches,  superior,  middle,  and  inferior.  The  superior  vestibular 
branch  gives  off  a  number  of  filaments  which  pass  through  the  minute 
openings  of  the  eminentia  pyramidalis  and  superior  ventricle  of  the  vesti- 
bule, and  are  distributed  to  the  sacculus  communis  and  ampulla?  of  the 
perpendicular  and  horizontal  semicircular  canals.  The  middle  vestibular 
branch  sends  off  numerous  filaments,  which  pass  through  the  openings  of 
the  macula  cribrosa  in  the  anterior  ventricle  of  the  vestibule,  and  are  dis- 
tributed to  the  sacculus  proprius.  The  inferior  and  smallest  branch  takes 
its  course  backwards  to  the  posterior  wall  of  the  vestibule,  and  gives  off 
filaments  which  pierce  the  wall  of  the  ampullary  dilatatioa  of  the  oblique 
canal  to  be  distributed  upon  its  ampulla.  According  to  Stiefensand  there 
is  in  the  situation  of  the  point  of  entrance  of  the  nervous  filaments  into  the 
ampulla  a  deep  depression  upon  the  exterior  of  the  membrane,  and  upon 
the  interior  a  corresponding  projection,  which  forms  a  kind  of  transverse 
septum,  partially  dividing  the  cavity  of  the  ampulla  into  two  chambers. 
In  the  substance  of  the  sacculi  and  ampulla?,  the  nervous  filaments  radiate 
in  all  directions,  anastomosing  with  each  other  and  forming  interlacements 
and  loops,  and  they  terminate  upon  the  inner  surface  of  the  membrane  in 
minute  papillae,  resembling  those  of  the  retina. 

The  Cochlear  nerve  divides  into  numerous  filaments  which  enter  the 
!_foramina  of  the  tractus  spiralis  foraminulentus  in  the  base  of  the  cochlea, 
and  passing  upwards  in  the  canals  of  the  modiolus,  bend  outwards  ajt  right 
angles,  to  be  distributed  in  the  tissue  of  the  lamina  spiralis.  The  central 
portion  of  the  nerve  passes  through  the  tubulus  centralis  of  the  modiolus, 
and  supplies  the  apicial  portion  of  the  lamina  spiralis.  In  the  lamina 
spiralis  the  nervous  filaments  lying  side  by  side  on  an  even  plane  form 
numerous  anastomosing  loops,  and  spread  out  into  a  nervous  membrane. 

*  Antonio  Scarpa  is  celebrated  for  several  beautiful  surgical  and  anatomical  mono- 
giaphs;  as,  for  example,  his  work  on  "Aneurism,"  "De  Auditu  et  Olfactu,"  &c.  An 
account  of  the  aqua  labyrinthi  will  be  found  in  his  anatomical  observations  "  De  Struc- 
:ri4  Fenestras  Rotund&e,  et  de  Tympano  Secundario." 


TONGUE — PAPILLAE.  467 

According  to  Treviranus  and  Gottsche,  the  ultimate  terminations  of  the 
filaments  assume  the  form  of  papillae. 

The  Arteries  of  the  labyrinth  are  derived  principally  from  the  auditory 
branch  of  the  superior  cerebellar  artery. 

O  RGAN   OF   TASTE. 

The  Tongue  is  composed  of  muscular  fibres,  which  are  distributed  in 
layers  arranged  in  various  directions :  thus,  some  are  disposed  longitudi- 
nally ;  others  transversely  ;  others,  again,  obliquely  and  vertically.  Between 
the  muscular  fibres  is  a  considerable  quantity  of  adipose  substance. 

The  tongue  is  connected,  posteriorly,  with  the  os  hyoides  by  muscular 
attachment ;  and  to  the  epiglottis  by  mucous  membrane,  which  forms  the 
three  folds  called  frcena  epiglottidis.  On  either  side  it  is  held  in  connex- 
ion with  the  lower  jaw  by  mucous  membrane,  and  in  front  a  fold  of  that 
membrane,  which  is  named  franum  linguce,  is  formed  beneath  its  under 
surface. 

The  surface  of  the  tongue  is  covered  by  a  dense  layer  analogous  to  the 
corium  of  the  skin,  which  gives  support  to  papillae.  A  raphe  marks  the 
middle  line  of  the  organ,  and  divides  it  into  symmetrical  halves. 

The  Papilla  of  the  tongue  are  the — 

Papillae  circumvallatae, 
Papillae  conicae, 
Papillae  filiformes, 
Papillae  fungiformes. 

The  Papillce  drcumvallata  (p.  lenticulares)  are 
of  large  size,  and  from  fifteen  to  twenty  in  number. 
They  are  situated  on  the  dorsum  of  the  tongue, 
near  its  root,  and  form  a  row  on  each  side,  which 
meets  its  fellow  at  the  middle  line,  like  the  two 
branches  of  the  letter  A.  Each  papilla  resembles 
a  cone,  attached  by  its  apex  to  the  bottom  of  a 
cup-shaped  depression  :  hence  they  are  also  named 
papillae  calyciform&.  This  cup-shaped  cavity  forms 
a  kind  of  fossa  around  the  papilla,  whence  their 
name  circumvallata.  At  the  meeting  of  the  two 
rows  of  these  papillae  upon  the  middle  of  the  root 
of  the  tongue,  is  a  deep  mucous  follicle  called  for- 
amen c<ecum. 

The  Papillce  conicce.  and  filiformes  cover  the 
whole  surface  of  the  tongue  in  front  of  the  circum- 
vallatse, but  are  most  abundant  towards  its  anterior 
part.  They  are  conical  and  filiform  in  shape,  and 
many  of  them  are  pierced  at  the  extremity  by  a 
minute  aperture.  Hence,  they  may  be  regarded  as 

*  The  tongue  with  its  papillae.  1.  The  raphe,  which  in  some  tongues  bifurcates  on 
the  dorsum  of  the  organ,  as  in  the  figure.  2,  2.  The  lobes  of  the  tongue.  The  rounded 
eminences  on  this  part  of  the  organ,  and  near  its  tip  are  the  papillae  fungiformes.  Tho 
smaller  papillae,  among  which  the  former  are  dispersed,  are  the  papillae  conicaa  and 
filiformes.  3.  The  tip  of  the  tongue.  4.  4.  Its  sides,  on  which  are  seen  the  lamellated 
and  fringed  papillae.  f>,  5.  The  A-shaped  row  of  papilla;  circumvallatae.  6.  The  fora 
men  caacum.  7.  The  mucous  glands  of  the  root  of  the  tongue.  8.  The  epiglottis.  9,  9. 
The  fraena  epiglottidis.  10,  10.  The  greater  cornua  of  the  os  hyoides. 


Fig.  207.* 


468  ORGAN    OF    TOUCH. 

follicles  rather  than  sentient  organs ;  the  true  sentient  papillse  being  ex 
tremely  minute  and  occupying  their  surface,  as  they  do  that  of  the  othei 
papillae  of  the  tongue. 

The  Papilla  fungiformes  (p.  capitate)  are  irregularly  dispersed  over 
the  dorsum  of  the  tongue,  and  are  easily  recognised  among  the  other 
papillae  by  their  rounded  heads  and  larger  size.  A  number  of  these  papillae 
will  generally  be  observed  at  the  tip  of  the  tongue. 

Behind  the  papillae  circumvallatae,  at  the  root  of  the  tongue,  are  a  num- 
ber of  mucous  glands,  which  open  upon  the  surface.  They  have  been  im- 
properly described  as  papillae  by  some  authors. 

Vessels  and  Nerves. — The  tongue  is  abundantly  supplied  with  blood  by 
the  lingual  arteries. 

The  Nerves  are  three  in  number,  and  of  large  size :  The  gustatory 
branch  of  the  fifth,  which  is  distributed  to  the  papillse,  and  is  the  nerve  of 
common  sensation  and  taste.  The  glosso-pharyngeal,  which  is  distributed 
to  the  mucous  membrane,  follicles,  and  glands  of  the  tongue,  is  a  nerve 
of  sensation  and  motion  ;  it  also  serves  to  associate  the  tongue  with  the 
pharynx  and  larynx.  The  hypoglossal  is  the  motor  nerve  of  the  tongue, 
and  is  distributed  to  the  muscles.  To  these  may  be  added  the  chorda 
tympani,  which  conveys  a  motor  influence  from  the  facial  nerve  to  the 
lingualis  muscle. 

The  Mucous  membrane  which  invests  the  tongue,  is  continuous  with 
the  derma  along  the  margin  of  the  lips.  On  either  side  of  the  freenum 
linguae  it  may  be  traced  through  the  sublingual  ducts  into  the  sublingual 
glands,  and  along  Wharton's*  ducts  into  the  submaxillary  glands  :  from 
the  sides  of  the  cheeks  it  passes  through  the  openings  of  Stenon'sf  ducts 
to  the  parotid  glands :  in  the  fauces,  it  forms  the  assemblage  of  follicles 
called  tonsils,  and  may  thence  be  traced  downwards  into  the  larynx  and 
pharynx,  where  it  is  continuous  with  the  general  gastro-pulmonary  mucous 
membrane. 

Beneath  the  mucous  membrane  of  the  mouth  are  a  number  of  small 
glandular  granules,  which  pour  their  secretion  upon  the  surface.  A  con- 
siderable number  of  them  are  situated  within  the  lips,  in  the  palate,  and 
in  the  floor  of  the  mouth.  They  are  named  from  the  position  which  they 
may  chance  to  occupy,  labial,  palatal  glands,  &c. 

ORGAN    OF    TOUCH. 

The  S/dn  is  the  exterior  investment  of  the  body,  which  it  serves  to 
cover  and  protect.  It  is  continuous  at  the  apertures  of  the  internal  cavities 
with  the  lining  membrane  of  those  cavities,  the  internal  skin  or  mucous 
membrane,  and  is  composed  essentially  of  two  layers,  derma  and  epiderma. 

The  DERMA  or  cutis  is  chiefly  composed  of  areolo-fibrous  tissue,  besides 
which  it  has  entering  into  its  structure  elastic  and  contractile  fibrous  tissue, 
together  with  blood-vessels,  lymphatic  vessels  and  nerves.  The  areolo- 
fibrous  tissue  exists  in  greatest  abundance  in  the  deeper  stratum  of  the 
derma,  which  is  consequently  dense,  white,  and  coarse ;  the  superficial 

*  Thomas  Wharton,  an  English  physician,  devoted  considerable  attention  to  the  ana- 
t->mv  of  the  various  glands;  his  work,  entitled  "  Adenographia,"  &c.,  was  published  in 
1056. 

f  Nicholas  Stenon,  a  Danish  anatomist:  he  was  made  professor  in  Copenhagen  in 
A672. 


STRUCTURE  OF  THE  DERMA.  469 

jtratum,  on  the  other  hand,  is  fine  in  texture,  reddish  in  colour,  soft, 
raised  into  minute  papillae,  and  highly  vascular  and  sensitive.  These  dif- 
ferences in  structure  have  given  rise  to  a  division  of  the  derma  into  the 
deep  stratum,  or  corium,  and  the  superficial,  or  papillary  layer. 

In  the  Corium  the  areolo-fibrous  tissue  is  collected  into  fasciculi,  which 
are  small  and  closely  interwoven  in  the  superficial  strata,  large  and  coarse 
in  the  deep  strata;  in  the  latter  forming  an  areolar  network  with  large 
areolse,  which  are  occupied  by  adipose  tissue.  These  areolae  are  the 
channels  by  wrhich  the  branches  of  vessels  and  nerves  find  a  safe  passage 
to  the  papillary  layer,  in  which  and  in  the  superficial  strata  of  the  corium 
they  are  principally  distributed.  The  yellow  elastic  tissue  is  found  chiefly 
in  the  superficial  strata,  the  red  contractile  tissue  in  the  deep.  It  is  to  the 
latter  that  the  nipples  and  scrotum  owe  their  contractile  powers,  and  the 
general  surface  of  the  skin  the  contraction  which  is  known  by  the  name 
of  cutis  anserina.  The  corium  presents  some  variety  in  thickness  in  dif- 
ferent parts  of  the  body.  Thus  in  the  more  exposed  regions,  as  the  back, 
the  outer  sides  of  the  limbs,  the  palms,  and  the  soles,  it  is  remarkable  for 
its  thickness ;  while  on  protected  parts  it  is  comparatively  thin.  On  the 
eyelids,  the  penis,  and  the  scrotum,  it  is  peculiarly  delicate.  It  is  con- 
nected by  its  under  surface  with  the  common  superficial  fascia  of  the  body. 

The  Papillary  layer  of  the  derma  is  raised  in  the  form  of  conical  promi- 
nences or  papillae.  On  the  general  surface  of  the  body  the  papillae  are 
short  and  exceedingly  minute  ;  but  in  other  situa- 

T*- 

tions,  as  the  palmar  surface  of  the  hands  and  fingers, 
and  the  plantar  surface  of  the  feet  and  toes,  they 
are  long  and  of  large  size.  They  also  differ  in 
arrangement ;  for,  on  the  general  surface  they  are 
distributed  at  equal  distances  and  without  order ; 
whereas,  on  the  palms  and  soles,  and  on  the  corre- 
sponding surfaces  of  the  fingers  and  toes,  they  are 
collected  into  little  square  clumps  containing  from 
ten  to  twenty  papillae ;  and  these  little  clumps  are 
disposed  in  parallel  rows.  It  is  this  arrangement 
in  rows  that  gives  rise  to  the  characteristic  parallel 
ridges  and  furrows  which  are  met  with  on  the  hands 
and  feet.  The  papillae  in  these  little  square  clumps 
are  for  the  most  part  uniform  in  size  and  length,  but  every  here  and  there 
one  papilla  may  be  observed  which  is  longer  than  the  rest.  The  largest 

*  Anatomy  of  a  portion  of  skin  taken  from  the  palm  of  the  hand.  1.  The  papillary 
layer,  in  which  the  longitudinal  furrows  (2)  marking  the  arrangement  of  the  papillte 
into  ridges  is  shown.  Each  ridge  is  moreover  divided  by  transverse  furrows  (3)  into 
small  quadrangular  clumps.  The  quadrangular  clumps  consist  of  a  tuft  of  minute 
conical  papilla;,  of  which  one  or  two  are  frequently  longer  and  larger  than  the  rest.  In 
this  figure  the  long  papillae  are  alone  seen,  the  rest  being  too  numerous  to  introduce  into 
a  wood-engraving.  4.  The  rete  mucosum  raised  from  the  papillary  layer  and  turned 
back;  the  under  surface  of  this  stratum  presents  an  accurate  impression  of  the  papillary 
layer;  on  which  are  seen  longitudinal  ridges  corresponding  with  the  longitudinal  fur 
rows,  transverse  ridges  corresponding  with  the  transverse  furrows,  and  quadrangula- 
depressions  corresponding  with  the  quadrangular  clumps  of  papillae.  Moreover,  wher- 
ever one  of  the  long  papilla;  exists,  a  distinct  conical  sheath  will  be  found  in  the  rele 
mucosum  5,  5.  Perspiratory  ducts  drawn  out  straight  by  the  separation  of  the  rete  ran- 
cosum  from  the  papillary  layer;  the  point  at  which  each  perspiratory  duct  issues  frotr 
the  papillary  layer,  and  pierces  the  rete  mucosum,  is  the  middle  of  the  transverse  furrow 
between  the  quadrangular  masses. 

40 


470  STRUCTURE    OF    THE    EPIDERMA. 

papillae  of  the  derma  are  those  which  produce  the  nail ;  in  the  dtrnial 
follicle  of  the  nail  they  are  long  and  filiform,  while  beneath  its  concave 
surface  they  form  longitudinal  and  parallel  plications  which  extend  for 
nearly  the  entire  length  of  that  organ.  In  structure  each  papilla  is  com- 
posed of  a  more  or  less  convoluted  capillary  and  a  more  or  less  convoluted 
nervous  loop. 

The  EPIDERMA  or  cuticle  (scarf-skin)  is  a  product  of  the  derma,  which 
it  serves  to  envelope  and  defend.  That  surface  of  the  epiderma  which  is 
exposed  to  the  influence  of  the  atmosphere  and  exterior  sources  of  injury 
is  hard  and  horny  in  texture,  while  that  which  lies  in  contact  with  the 
papillary  layer  is  soft  and  cellular.  Hence  the  epideima,  like  the  derma, 
is  divisible  into  two  layers,  external  and  internal,  the  latter  being  termed 
the  rete  mucosum.  Moreover,  the  epiderma  is  laminated  in  structure,  and 
the  laminae  present  a  progressively  increasing  tenuity  and  density  as  they 
advance  from  the  inner  to  the  outer  surface.  This  difference  of  density  is 
dependent  on  the  mode  of  growth  of  the  epiderma,  for  as  the  external 
surface  is  constantly  subjected  to  destruction  from  attrition  and  chemical 
action,  so  the  membrane  is  continually  reproduced  on  its  internal  surface  ; 
new  layers  being  successively  formed  on  the  derma  to  take  the  place  of 
the  old. 

The  theory  of  growth  of  the  epiderma,  deduced  from  the  observations 
of  Schwann,  is  as  follows : — A  stratum  of  plastic  lymph  (liquor  sanguinis) 
is  poured  out  upon  the  surface  of  the  derma.  This  fluid,  by  virtue  of  the 
vital  force  inherent  in  itself,  and  communicated  to  it  by  contact  with  a 
living  tissue,  is  converted  into  granules,  which  are  termed  cell-germs,  or 
cyto-blasts.  By  endosmosis,  these  cyto-blasts  imbibe  serum  from  the. 
plastic  lymph  and  adjacent  tissues,  and  the  outermost  layer  or  pellicle  of 
the  cyto-blast  becomes  gradually  distended  by  the  imbibed  fluid.  The 
cyto-blast  has  now  become  a  cell,  and  the  solid  portion  of  the  cyto-blast, 
which  always  remains  adherent  to  some  one  point  of  the  internal  surface 
of  the  cell-membrane,  is  the  nucleus  of  the  cell. 
Fig.  209.*  Moreover,  within  the  nucleus  one  or  several  nuclei 

are  formed  which  are  termed  nucleoli.  By  a  con- 
tinuance of  the  process  of  imbibition,  the  cell  be- 
comes more  or  less  spherical ;  so  that,  after  a  time, 
every  part  of  the  surface  of  the  papillary  layer  of 
the  derma  is  coated  by  a  thin  and  membranous 
stratum,  consisting  of  spherical  cells  lying  closely 
pressed  together,  and  corresponding  with  every 
irregularity  which  the  papillse  present.  But,  as 
this  production  of  cells  is  a  function  constantly  in 
operation,  a  new  layer  is  formed  before  the  first  is 
completed,  and  the  latter  is  separated  by  subsequent  formations  farther 
and  farther  from  the  surface  of  the  papillary  layer.  As  a  consequence 
of  loss  of  contact  with  the  derma,  the  vital  force  is  progressively  dimi- 

*  A  diagiam  illustrative  of  the  development  of  the  epiderma,  and  of  epithelia  in 
general,  according  to  the  theory  of  Schwann.  1.  A  granule  or  cyto-blast.  2.  The  cell 
seen  rising  on  the  cyto-blast;  the  latter  is  now  a  nucleus,  and  a  nucleolus  may  be  de- 
tected in  its  interior.  3.  The  spheroidal  cell.  4.  The  oval  cell.  5.  The  elliptical  cell. 
C  The  flattened  cell;  which,  by  contact  of  its  walls,  is  speedily  converted  into  a  scale 
MI  which  the  nucleus  is  lost.  7.  A  nucleated  scale  as  seen  upon  its  flat  surface.  8.  A 
cluster  of  such  scales 


STRUCTURE    OF    THE    EPIDERMA.  471 

nished ;  the  cell  becomes  subject  to  the  influence  of  physical  laws,  and 
evaporation  of  its  fluid  slowly  ensues.  In  consequence  of  this  evapora- 
tion, the  cell  becomes  collapsed  and  flattened,  and  assumes  an  elliptical 
form ;  the  latter  is  by  degrees  converted  into  the  flat  cell  with  parallel  and 
contiguous  layers,  and  an  included  nucleolated  nucleus ;  and  lastly,  the 
flattened  cell  desiccates  into  a  thin  membranous  scale,  in  which  the  nucleus 
is  no  longer  apparent. 

My  own  investigations*  have  shown  that,  after  the  original  granules  of 
the  liquor  sanguinis  have  become  aggregated  into  a  granular  nucleus,  other 
granules  are  formed  in  successive  circles,  around  the  circumference  of  the 
nucleus,  until  the  entire  breadth  of  the  epidermal  scale  is  attained ;  that 
the  cell  never  acquires  a  greater  thickness  than  that  of  the  original  nucleus, 
and,  that  the  formation  of  the  scale  results  from  the  desiccation  of  the  cell, 
as  it  is  gradually  pushed  outwards  from  the  derma  towards  the  surface. 
Consequently,  the  cell  never  possesses  any  other  than  the  flattened  form ; 
all  its  phases  of  growth  are  perfected  in  the  deepest  layer  of  the  epiderma  ; 
and,  in  its  internal  structure,  it  is  a  parent  cell  containing  secondary  and 
tertiary  cells  and  granules,  its  growth  being  the  result  of  the  growth  of 
these  secondary  formations. 

The  under  surface  of  the  epiderma  is  accurately  modelled  on  the  papil- 
lary layer  of  the  derma,  each  papilla  having  its  appropriate  sheath  in  the 
newly-formed  epiderma  or  rete  mucosum,  and  each  irregularity  of  surface 
of  the  former  having  its  representative  in  the  soft  tissue  of  the  latter.  On 
the  external  surface,  this  character  is  lost ;  the  minute  elevations  corre- 
sponding with  the  papillae,  are,  as  it  were,  polished  down,  and  the  surface 
is  rendered  smooth  and  uniform.  The  palmar  and  plantar  surfaces  of  the 
hands  and  feet  are,  however,  an  exception  to  this  rule ;  for  here,  in  con- 
sequence of  the  large  size  of  the  papillae  and  their  peculiar  arrangement  in 
rows,  ridges  corresponding  with  the  papillae  are  strongly  marked  on  the 
superficial  surface  of  the  epiderma.  The  epiderma  is  remarkable  for  its 
thickness  in  situations  where  the  papillae  are  large,  as  in  the  palms  and 
soles.  In  other  situations,  it  assumes  a  character  which  is  also  due  to  the 
nature  of  the  surface  of  the  derma ;  namely,  that  of  being  marked  by  a 
network  of  linear  furrows,  which  trace  out  the  surface  into  small  polygonal 
and  lozenge-shaped  area?.  These  lines  correspond  with  the  folds  of  the 
derma  produced  by  its  movements,  and  are  most  numerous  where  those 
movements  are  the  greatest,  as  in  the  flexures  and  on  the  convexities  of 
joints. 

The  dark  colour  of  the  skin  among  the  natives  of  the  South  is  due  to 
the  coloration  of  the  primitive  granules  of  which  the  cell  is  composed,  es- 
pecially the  nucleus.  As  the  cells  desiccate,  the  colour  of  the  granules  is 
gradually  lost ;  hence  the  deeper  hue  of  the  rete  mucosum. 

The  pores  of  the  epiderma  are  the  openings  of  the  perspiratory  ducts, 
hair  follicles,  and  sebiparous  glands. 

Vessels  and  Nerves. — The  Arteries  of  the  derma  which  enter  its  struc- 
ture through  the  areolae  of  the  under  surface  of  the  corium,  divide  into  in- 
numerable intermediate  vessels,  which  form  a  rich  capillary  plexus  in  the 
superficial  strata  of  the  skin  and  in  its  papillary  layer.  In  the  papillae  of 
some  parts  of  the  derma,  as  in  the  longitudinal  plications  beneath  the  nail, 
the  capillary  vessels  form  simple  loops,  but  in  other  papillae  they  are  con 
voluted  to  a  greater  or  less  degree  in  proportion  to  the  size  and  importance 

*  Diseases  of  the  Skin,  2d  edition,  p.  5. 


472  APPENDAGES    OF    THE    SKIN. 

of  the  papillae.  The  Lymphatic  vessels  probably  form,  in  the  superficial 
strata  of  the  derma,  a  plexus,  the  meshes  of  which  are  interwoven  with 
those  of  the  capillary  and  nervous  plexus.  No  lymphatics  have  as  yet 
been  discovered  in  the  papillae. 

The  Nerves  of  the  derma,  after  entering  the  areolae  of  the  deeper  part 
of  the  corium,  divide  into  minute  fasciculi,  which  form  a  terminal  plexus 
in  the  upper  strata  of  the  corium.  From  this  plexus  the  primitive  fibres 
pass  off  to  their  distribution,  as  loops,  in  the  papillae.  In  the  less  sensitive 
parts  of  the  skin  the  loops  are  simple  and  more  or  less  acute  in  their  bend, 
in  conformity  with  the  figure  of  the  papilla.  In  the  sensitive  parts,  how- 
ever, and  especially  in  the  tactile  papilla?  of  the  pulps  of  the  fingers,  the 
loop  is  convoluted  to  a  greater  or  less  extent,  and  acts  as  a  multiplier  of 
sensation. 

APPENDAGES    OF    THE    SKIN. 

The  appendages  of  the  skin  are  the  nails,  hairs,  sebiparous  glands,  and 
perspiratory  glands  and  ducts. 

The  NAILS  are  horny  appendages  of  the  skin,  identical  in  formation 
with  the  epiderma,  of  which  they  are  a  part.  A  nail  is  convex  on  its  ex- 
ternal surface,  concave  within,  and  implanted  by  means  of  a  thin  margin 
or  root  in  a  fold  of  the  derma  (matrix),  which  is  nearly  two  lines  in  depth, 
and  acts  the  part  of  a  follicle  to  the  nail.  At  the  bottom  of  the  groove  of 
the  follicle  are  a  number  of  filiform  papillae,  which  produce  the  margin  of 
the  root,  and,  by  the  successive  formation  of  new  cells,  push  the  nail  on- 
wards in  its  growth.  The  concave  surface  of  the  nail  is  in  contact  with 
the  derma,  and  the  latter  is  covered  by  papilla?,  which  perform  the  double 
office  of  retaining  the  nail  in  its  place,  and  giving  it  increased  thickness  by 
the  addition  of  newly-formed  cells  to  its  under  surface.  It  is  this  constant 
change  occurring  in  the  under  surface  of  the  nail,  co-operating  with  the 
continual  reproduction  taking  place  along  the  margin  of  the  root,  which 
ensures  the  growth  of  the  nail  in  the  proper  direction.  The  nail  derives 
a  peculiarity  of  appearance  from  the  disposition  and  form  of  the  papilla?  on 
the  ungual  surface  of  the  derma.  Thus,  beneath  the  root,  and  for  a  short 
distance  onwards  towards  its  middle,  the  derma  is  covered  by  papillae 
which  are  more  minute,  and  consequently  less  vascular  than  the  papillae 
somewhat  farther  on.  This  patch  of  papillae  is  bounded  by  a  semilunar 
line,  and  that  part  of  the  nail  covering  it  being  lighter  in  colour  than  the 
rest,  has  been  termed  lunula.  Beyond  the  lunula  the  papillae  are  raised 
into  longitudinal  plaits,  which  are  exceedingly  vascular,  and  give  a  deeper 
tint  of  redness  to  the  nail.  These  plait-like  papillae  of  the  derma  are  well 
calculated  by  their  form  to  offer  an  extensive  surface  both  for  the  adhesion 
and  formation  of  the  nail.  The  granules  and  cells  are  developed  on  every 
part  of  their  surface,  both  in  the  grooves  between  the  plaits  and  on  their 
sides,  and  a  horny  lamina  is  formed  between  each  pair  of  plaits.  When 
the  under  surface  of  a  nail  is  examined,  these  longitudinal  lamina?,  corre- 
sponding with  the  longitudinal  papillae  of  the  ungual  portion  of  the  derma, 
are  distintly  apparent,  and  if  the  nail  be  forcibly  detached,  the  lamina?  may 
be  seen  in  the  act  of  parting  from  the  grooves  of  the  papilla?.  It  is  this 
structure  that  gives  rise  to  the  ribbed  appearance  of  the  nail.  The  papil- 
lary surface  of  the  derma  which  produi  es  the  nail  is  continuous  around  the 
circumference  of  the  attached  part  of  that  organ  with  the  derma  of  the  sur- 


STRUCTURE    OF    HAIRS. 


473 


Fig.  210.* 


rounding  skin,  and  the  horny  structure  of  the  nail  is  consequently  continu- 
ous with  that  of  the  epiderma. 

HAIRS  are  horny  appendages  of  the  skin  produced  by  the  involution  and 
subsequent  evolution  of  the  epiderma ;  the  involution  "constituting  the  fol 
licle  in  which  the  hair  is  enclosed,  and 
the  evolution  the  shaft  of  the  hair.  Hairs 
vary  much  in  size  and  length  in  different 
parts  of  the  body  ;  in  some  they  are  so 
short  as  not  to  appear  beyond  the  folli- 
cle ;  in  others  they  grow  to  a  great 
length,  as  on  the  scalp  ;  while  along  the 
margins  of  the  eyelids  and  in  the  whis- 
kers and  beard,  they  are  remarkable  for 
their  thickness.  Hairs  are  generally 
more  or  less  flattened  in  form,  and  when 
the  extremity  of  a  transverse  section  is 
examined  it  is  found  to  possess  an  el- 
liptical or  reniform  outline.  This  ex- 
amination also  demonstrates  that  the 
centre  of  the  hair  is  porous  and  loose  in 
texture,  while  its  periphery  is  dense ; 
thus  affording  ground  for  its  division 
into  a  cortical  and  a  medullary  portion. 
The  free  extremity  of  a  hair  is  generally 
pointed,  and  sometimes  split  into  two  or  three  filaments.  Its  attached 
extremity  is  implanted  deeply  in  the  integument  extending  through  the 
derma  into  the  sub-cutaneous  areolar  tissue,  where  it  is  surrounded  by 
adipose  cells.  The  central  extremity  of  a  hair  is  larger  than  its  shaft,  and 
is  called  the  root  or  bulb.  It  is  usually  conical  in  its  shape. 

The  process  of  formation  of  a  hair  by  its  follicle  is  identical  with  that  of 
the  formation  of  the  epiderma  by  the  papillary  layer  of  the  derma.  Plastic 
lymph  is  in  the  first  instance  exuded  by  the  capillary  plexus  of  the  follicle, 
the  lymph  undergoes  conversion,  first  into  granules,  then  into  cells,  and 
the  latter  are  elongated  into  fibres.  The  cells  which  are  destined  to  form 
the  surface  of  the  hair  go  through  a  different  process.  They  are  converted 
into  flat  scales,  which  enclose  the  fibrous  structure  of  the  interior.  These 
scales,  as  they  are  successively  produced,  overlap  those  which  precede 
and  give  rise  to  the  prominent  and  waving  lines  which  may  be  seen 
around  the  circumference  of  a  hair.  It  is  this  overlapping  line  that  is  the 
cause  of  the  roughness  which  wre  experience  in  drawing  a  hair,  from  its 
point  to  its  bulb,  between  the  fingers.  The  bulb  is  the  newly  formed 
portion  of  the  hair ;  its  expanded  form  is  due  to  the  greater  bulk  of  the 
fresh  cells  compared  with  the  fibres  and  scales  into  which  they  are  subse- 
quently converted  in  the  shaft. 

*  The  anatomy  of  the  skin.  1.  The  epiderma.  2.  The  rete  mucosum  or  deep  layei 
of  the  epiderma.  3.  Two  of  the  quadrilateral  papillary  clumps,  such  as  are  seen  in  the 
palm  of  the  hand  or  sole  of  the  foot;  they  are  composed  of  minute  conical  papillce.  4. 
The  deep  layer  of  the  derma,  the  corium.  5.  Adipose  cells.  6.  A  sudoriparous  gland 
with  its  spiral  duct,  such  as  is  seen  in  the  palm  of  the  hand  or  sole  of  the  foot. 
Another  sudoriparous  gland  with  a  straighter  duct,  such  as  is  ?een  in  the  scalp.  8, 
Two  hairs  from  the  scalp,  enclosed  in  their  follicles ;  their  relative  depth  in  the  skin  is 
preserved.  9.  A  pair  of  sebiparous  glands,  opening  by  short  ducts  into  the  follicle  of 
the  hair. 

40* 


474  SUDORIPAROUS    GLANDS. 

The  colour  of  the  hair,  like  that  of  the  epiderma,  is  due  to  the  colora 
tion  of  the  primitive  granules  of  the  cells. 

The  SEBIPAROUS  GLANDS  are  sacculated  glandular  organs  embedded  in 
the  substance  of  the  derma,  and  presenting  every  variety  of  complexity, 
from  the  simplest  pouch-like  follicle  to  the  sacculated  and  lobulated  gland. 
In  some  situations,  the  excretory  ducts  of  these  glands  open  independently 
on  the  surface  of  the  epiderma ;  while  in  others,  and  the  most  numerous, 
they  terminate  in  the  follicles  of  the  hairs.  The  sebiparous  glands  asso- 
ciated with  the  hairs  are  racemiform  and  lobulated  in  structure,  consisting 
of  sacculi  which  open  by  short  pedunculated  tubuli  into  a  common  excre- 
tory duct,  and  the  latter,  after  a  short  course,  terminates  in  the  hair-follicle. 
In  the  scalp  there  are  two  of  these  glands  to  each  hair-follicle.  On  the 
nose  and  face  the  glands  are  of  large  size,  distinctly  lobulated,  and  con- 
stantly associated  with  small  hair-follicles.  In  the  meatus  auditorius  the 
sebiparous  (ceruminous)  glands  are  also  large  and  lobulated,  but  the 
largest  are  those  of  the  eyelids,  the  Meibomian  glands.  The  excretory 
ducts  of  sebiparous  glands  offer  some  diversity  in  different  parts  of  the 
body:  thus,  in  many  situations  they  are  short  and  straight,  while  in  others, 
as  in  the  palms  of  the  hands  and  soles  of  the  feet,  where  the  epiderma  is 
thick,  they  assume  a  spiral  arrangement.  The  sebiferous  ducts  are  lined 
by  an  inversion  of  the  epiderma,  which  forms  a  thick  and  funnel-shaped 
cone  at  its  commencement,  but  soon  becomes  uniform  and  soft.  Sebi- 
parous glands  are  met  with  in  all  parts  of  the  body,  but  are  most  abundant 
in  the  skin  of  the  face,  and  in  those  situations  which  are  naturally  exposed 
to  the  influence  of  friction. 

The  sebaceous  substance,  when  it  collects  in  inordinate  quantities  within 
the  excretory  ducts,  becomes  the  habitat  of  a  very  remarkable  parasitic 
animal,  the  steatozoon  folliculorum. 

The  SUDORIPAROUS  GLANDS  are  situated  deeply  in  the  corium  and  also 
in  the  subcutaneous  areolar  tissue,  where  they  are  surrounded  by  adipose 
cells.  They  are  small,  oblong  bodies,  composed  of  one  or  more  convo- 
luted tubuli,  or  of  a  congeries  of  globular  sacs,  which  open  into  a  common 
efferent  duct.  The  latter  ascends  from  the  gland  through  the  derma  and 
epiderma,  and  terminates  on  the  surface  by  a  funnel-shaped  and  oblique 
aperture  or  pore.  The  efferent  duct  presents  some  variety  in  its  course 
upwards ;  thus  within  the  derma  it  is  curved  and  serpentine,  and  if  the 
epiderma  be  thin,  it  proceeds  more  or  less  directly  to  the  excreting  pore. 
Sometimes  it  is  spirally  curved  within  the  derma,  and  having  passed  the 
latter,  is  regularly  and  beautifully  spiral  in  its  passage  through  the  epi- 
derma, the  last  turn  forming  an  oblique  and  valvular  opening  on  the  sur- 
face. The  spiral  course  of  the  duct  is  especially  remarkable  in  the  thick 
epiderma  of  the  palm  of  the  hand  and  sole  of  the  foot.  On  those  parts  of 
the  skin  where  the  papilla  are  irregularly  distributed,  the  efferent  ducts  of 
the  sudoriparous  glands  open  on  the  surface  also  irregularly,  while  on  the 
palmar  and  plantar  surfaces  of  the  hands  and  feet,  the  pores  are  situated  at 
regular  distances  along  the  ridges,  at  points  corresponding  with  the  inter- 
vals of  the  small,  square-shaped,  clumps  of  papillae.  Indeed,  the  aper- 
tures of  the  pores,  seen  upon  the  surface  of  the  epidermal  ridges,  give  rise 
to  the  appearance  of  small  transverse  furrows,  which  intersect  the  ridges 
from  point  to  point. 

The  efferent  duct  and  the  component  sacs  and  tubuli  of  the  sudoriparous 
giund  are  lined  by  an  inflection  of  the  epiderma.  This  inflection  is  thick 


OF    THE    VISCERA.  475 

and  infundibuliform  in  the  upper  stratum  of  the  derma,  but  soon  becomes 
uniform  and  soft.  The  infundibuliform  projection  is  drawn  out  from  the 
duct  when  the  epiderma  is  removed,  and  may  be  perceived  on  the  under 
surface  of  the  latter  as  a  nipple-shaped  cone.  A  good  view  of  the  sudo- 
riferous ducts  is  obtained  by  gently  separating  the  epiderma  of  a  portion 
of  decomposing  skin  ;  or  they  may  be  better  seen  by  scalding  a  piece  of 
skin,  and  then  withdrawing  the  epiderma  from  the  derma.  In  both  cases 
it  is  the  lining  sheath  of  epiderma  which  is  drawn  out  from  the  duct. 


CHAPTER    XI.  H, 

OF  THE  VISCERA. 

THAT  part  of  the  science  of  anatomy  which  treats  of  the  viscera  is 
named  splanchnology,  from  the  Greek  words  ovAa^vov,  viscus,  and  Xoyo?. 
The  viscera  of  the  human  body  are  situated  in  the  three  great  internal 
cavities  :  cranio-spinal,  thorax,  and  abdomen.  The  viscera  of  the  cranio- 
spinal  cavity,  namely,  the  brain  and  spinal  cord,  with  the  principal  organs 
of  sense,  have  been  already  described,  in  conjunction  with  the  nervous 
system.  The  viscera  of  the  chest  are  :  the  central  organ  of  circulation, 
the  heart ;  the  organs  of  respiration,  the  lungs ;  and  the  thymus  gland. 
The  abdominal  viscera  admit  of  a  subdivision  into  those  which  properly 
beiong  to  that  cavity,  viz.,  the  alimentary  canal,  liver,  pancreas,  spleen, 
kidneys,  and  supra-renal  capsules ;  and  those  of  the  pelvis ;  the  bladder 
and  internal  organs  of  generation. 


THORAX. 


The  thorax  is  the  conical  cavity,  situated  at  the  upper  part  of  the  trunk 
of  the  body ;  it  is  narrow  above  and  broad  below,  and  is  bounded  by  the 
sternum,  six  superior  costal  cartilages,  ribs,  and  intercostal  muscles  in 
front ;  laterally,  by  the  ribs  and  intercostal  muscles  ;  and,  behind,  by  the 
same  structures,  and  by  the  vertebral  column,  as  low  down  as  the  upper 
border  of  the  last  rib  and  the  first  lumbar  vertebra ;  superiorly,  by  the 
thoracic  fascia  and  first  rib  ;  and  inferiorly,  by  the  diaphragm.  This 
cavity  is  much  deeper  on  the  posterior  than  on  the  anterior  wall,  in  con- 
sequence of  the  obliquity  of  the  diaphragm,  and  contains  the  heart  en- 
closed in  its  pericardium,  with  the  great  vessels ;  the  lungs,  with  their 
serous  coverings,  the  pleurae;  the  oesophagus;  some  important  nerves; 
and,  in  the  foetus,  the  thymus  gland. 

THE     HEART. 

The  central  organ  of  circulation,  the  heart,  is  situated  between  the  two 
layers  of  pleura  which  constitute  the  mediastinum,  and  is  enclosed  in  a 
proper  membrane,  the  pericardium. 

Pericardium. — The  pericardium  is  a  fibro-serous  membrane  like  the 
dura  mater,  and  resembles  that  membrane  in  deriving  its  serous  layer  from 
the  reflected  serous  membrane  of  the  viscus  which  it  encloses.  It  consists, 
therefore,  of  two  layers,  an  external  fibrous  and  an  internal  serous.  The 


476 


THE    HEART. 


fibrous  layer  is  attached,  above,  to  the  great  vessels  at  the  root  of  the 
heart,  where  it  is  continuous  with  the  thoracic  fascia ;  and  below,  to  the 
tendinous  portion  of  the  diaphragm.  The  serous  membrane  invests  the 
heart  with  the  commencement  of  its  great  vessels,  and  is  then  reflected 
upon  the  internal  surface  of  the  fibrous  layer. 


Fig.  211.*  The  HEART  is  placed  obliquely  in 

the  chest,  the  base  being  directed  up- 
wards and  backwards  towards  the 
right  shoulder  ;  the  apex  forwards  and 
to  the  left,  pointing  to  the  space  be- 
tween the  fifth  and  sixth  ribs,  at  about 
two  or  three  inches  from  the  sternum. 
Its  under  side  is  flattened,  and  rests 
upon  the  tendinous  portion  of  the  dia- 
phragm ;  its  upper  side  is  rounded  and 
convex,  and  formed  principally  by  the 
right  ventricle,  and  partly  by  the  left. 
Surmounting  the  ventricles  are  the 
corresponding  auricles,  whose  auricu- 
lar appendages  are  directed  forwards, 
and  slightly  overlap  the  root  of  the 
pulmonary  artery.  The  pulmonary 

artery  is  the  large  anterior  vessel  at  the  root  of  the  heart ;  it  crosses  ob- 
liquely the  commencement  of  the  aorta.  The  heart  consists  of  two  auri- 
cles and  two  ventricles,  which  are  respectively  named,  from  their  position, 
right  and  left.  The  right  is  the  venous  side  of  the  heart ;  it  receives  into 
its  auricle  the  venous  blood  from  every  part  of  the  body,  by  the  superior 
and  inferior  cava  and  coronary  vein.  From  the  auricle  the  blood  passes 
into  the  ventricle,  and  from  the  ventricle  through  the  pulmonary  artery,  to 
the  capillaries  of  the  lungs.  From  these  it  is  returned  as  arterial  blood  to 
the  left  auricle  ;  from  the  left  auricle  it  passes  into  the  left  ventricle ; .  and 

*  The  anatomy  of  the  heart.  1.  The  right  auricle.  2.  The  entrance  of  the  superior 
vena  cava.  3.  The  entrance  of  the  inferior  cava.  4.  The  opening  of  the  coronary  vein, 
half  closed  by  the  coronary  valve.  5.  The  Eustachian  valve.  6.  The  fossa  ovalis, 
surrounded  by  the  annulus  ovalis.  7.  The  tubereulum  Loweri.  8.  The  musculi  pecti- 
nati  in  the  appendix  auriculae.  9.  The  auriculo-ventricuiar  opening.  10.  The  cavity 
of  the  right  ventricle.  11.  The  tricuspid  valve,  attached  by  the  chordse  tendinese  to  the 
carneEe  columnae  (12).  13.  The  pulmonary  artery,  guarded  at  its  commencement  by 
three  semilunar  valves.  14.  The  right  pulmonary  artery,  passing  beneath  the  arch  and 
behind  the  ascending  aorta.  15.  The  left  pulmonary  artery,  crossing  in  front  of  the  de 
scending  aorta.  *  The  remains  of  the  ductus  arteriosus,  acting  as  a  ligament  between 
the  pulmonary  artery  and  arch  of  the  aorta.  The  arrows  mark  the  course  of  the  venous 
blood  through  the  right  side  of  the  heart.  Entering  the  auricle  by  the  superior  and  in 
ferior  cavae,  it  passes  through  the  auriculo-ventricuiar  opening  into  the  ventricle,  and 
thence  through  the  pulmonary  artery  to  the  lungs.  10.  The  left  auricle.  17.  The  open 
ings  of  the  fourth  pulmonary  veins.  18.  The  auriculo-ventricuiar  opening.  19.  The 
left  ventricle.  20.  The  mitral  valve,  attached  by  its  chordae  tendinese  to  two  large  co-" 
'umnae  carneae,  which  project  from  the  walls  of  the  ventricle.  21.  The  commencement 
and  course  of  the  ascending  aorta  behind  the  pulmonary  artery,  marked  by  an  arrow. 
The  entrance  of  the  vessel  is  guarded  by  three  semilunar  valves.  22.  The  arch  of  the 
aorta.  The  comparative  thickness  of  the  two  ventricles  is  shown  in  the  diagram.  The 
course  of  the  pure  blood  through  the  left  side  of  the  heart  is  marked  by  arrows.  The 
blood  is  brought  from  the  lungs  by  the  four  pulmonary  veins  into  the  left  auricle,  and 
passes  through  the  auriculo-ventricuiar  opening  into  the  left  ventricle,  whence  it  is  con 
veyed  by  the  aorta  to  every  part  of  the  body. 


RIGHT   AURICLE.  477 

from  the  left  ventricle  is  carried  through  the  aorta,  to  be  distributed  to 
every  part  of  the  body,  and  again  returned  to  the  heart  by  the  veins 
This  constitutes  the  course  of  the  adult  circulation. 

The  heart  is  best  studied  in  situ.  If,  however,  it  be  removed  from  the 
body,  it  should  be  placed  in  the  position  indicated  in  the  above  descrip- 
tion of  its  situation.  A  transverse  incision  should  then  be  made  along 
the  ventricular  margin  of  the  right  auricle,  from  the  appendix  to  its  rio-ht 
border,  and  crossed  by  a  perpendicular  incision,  carried  from  the  side  of 
the  superior  to  the  inferior  cava.  The  blood  must  then  be  removed. 
Some  fine  specimens  of  white  fibrin  are  frequently  found  with  the  coagula ; 
occasionally  they  are  yellow  and  gelatinous*  This  appearance  deceived 
the  older  anatomists,  who  called  these  substances  "  polypus  of  the  heart:" 
they  are  also  frequently  found  in  the  right  ventricle,  and  sometimes  in  die 
left  cavities. 

The  RIGHT  AURICLE  is  larger  than  the  left,  and  is  divided  into  a  prin- 
cipal cavity  or  sinus,  and  an  appendix  auricula?.  The  interior  of  the  sinus 
presents  for  examination  five  openings ;  two  valves  ;  two  relicts  of  foetal 
structure;  and  two  peculiarities  in  the  proper  structure  of  the  auriclf, 
They  may  be  thus  arranged : — 

Superior  cava, 
Interior  cava, 


Openings 


Coronary  vein, 
Foramina  Thebesii, 
Auriculo-ventricular  opening. 


v  j  (  Eustachian  valve, 

r    ......  I  Coronary  valve. 

r>  7-  4.     X-  j-  j.  i   t  {  Annulus  ovalis, 

Relicts  of  fatal  structure  j  Fosga  Qy^ 

,..,          .  ,  (  Tuberculum  Loweri, 
Structure  of  the  auncle  .         Musculi          n 


The  Superior  cava  returns  the  blood  from  the  upper  half  of  the  body, 
and  opens  into  the  upper  and  front  part  of  the  auricle.  , 

The  Inferior  cava  returns  the  blood  from  the  lower  half  of  the  body, 
and  opens  through  the  lower  and  posterior  wall,  close  to  the  partition 
between  the  auricles  (septum  auricularum).  The  direction  of  these  two 
vessels  is  such,  that  a  stream  forced  through  the  superior  cava  would  be 
directed  towards  the  auriculo-ventricular  opening.  In  like  manner,  a 
stream  rushing  upwards  by  the  inferior  cava  would  force  its  current  against 
the  septum  auricularum  ;  this  is  the  proper  direction  of  the  two  currents 
during  foetal  life. 

The  Coronary  vein  returns  the  venous  blood  from  the  substance  of  the 
heart  ;  it  opens  into  the  auricle  between  the  inferior  cava  and  the  auriculo- 
ventricular  opening,  under  cover  of  the  coronary  valve. 

The  Foramina  Thebesii*  are  minute  pore-like  openings,  by  which  the 
venous  blood  exudes  directly  from  the  muscular  structure  of  the  heart  into 
the  auricle,  without  entering  the  venous  current.  These  openings  are  also 
found  in  the  left  auricle,  and  in  the  right  and  left  ventricles. 

*  Adarn  Christian  Thebesius.  His  discovery  of  the  openings  now  known  by  hit 
name  is  contained  in  his  "  Dissertatio  Medica  de  Circulo  Sanguinis  in  Corde,"  1708. 


478  RIGHT    AURICLE. 

The  rfuriculo-ventricular  opening  is  the  large  opening  of  communica- 
tion between  the  auricle  and  ventricle. 

The  Eustachian*  valve  is  a  part  of  the  apparatus  of  foetal  circulation, 
and  serves  to  direct  the  placental  blood  from  the  inferior  cava,  though  the 
foramen  ovale  into  the  left  auricle.  In  the  adult  it  is  a  mere  vestige  and 
imperfect,  though  sometimes  it  remains  of  large  size.  It  is  formed  by  a 
fold  of  the  lining  membrane  of  the  auricle,  containing  some  muscular 
fibres,  is  situated  between  the  opening  of  the  inferior  cava  and  the  auriculo- 
ventricular  opening,  and  is  generally  connected  with  the  coronary  valve. 

The  Coronary  valve  is  a  semilunar  fold  of  the  lining  membrane,  stretch- 
ing across  the  mouth  of  the  coronary  vein,  and  preventing  the  reflux  of 
the  blood  in  the  vein  during  the  contraction  of  the  auricle. 

The  Anmdus  ovalis  is  situated  on 

Fig.  2i2.f  the  septum  auricularum,  opposite  the 

termination  of  the  inferior  cava.  It 
is  the  rounded  margin  of  the  septum, 
which  occupies  the  place  of  the  fora- 
men ovale  of  the  fetus. 

The  Fossa  ovalis  is  an  oval  de- 
pression corresponding  with  the  fora- 
men ovale  in  the  foetus.  This  opening 
is  closed  at  birth  by  a  thin  valvular 
layer,  which  is  continuous  with  the 
left  margin  of  the  annulus,  and  is 
frequently  imperfect  at  its  upper  part. 
The  depression  or  fossa  in  the  right 
auricle  results  from  this  arrangement. 
There  is  no  fossa  ovalis  in  the  left 
auricle. 

The    Tuberculum  Loweri\   is  the 

portion  of  auricle  intervening  between  the  openings  of  the  superior  and 
inferior  cava.    Being  thicker  than  the  walls  of  the  veins,  it  forms  a  projec- 

*  Bartholomew  Eustachius,  born  at  San  Severino,  in  Naples,  was  Professor  of  Medi 
cine  in  Rome,  where  he  died  in  1570.  He  was  one  of  the  founders  of  modern  anato- 
my, and  thg  first  who  illustrated  his  works  with  good  engravings  on  copper. 

j-  The  anatomy  of  the  heart ;  the  organ  is  viewed  upon  the  right  side.  1.  The  cavity 
of  the  right  auricle.  2.  The  appendix  auriculae,  in  the  cavity  of  which  the  musculi 
pectinati  are  seen.  3.  The  superior  vena  cava,  opening  into  the  upper  part  of  the  right 
auricle.  4.  The  inferior  vena  cava.  5.  The  fossa  ovalis ;  the  prominent  ridge  sur- 
rounding it  is  the  annulus  ovalis.  6.  The  Eustachian  valve.  7.  The  opening  of  the 
coronary  vein.  8.  The  coronary  valve.  9.  The  entrance  of  the  auriculo-ventricular 
opening.  Between  the  numbers  1  and  9,  two  or  three  of  the  foramina  Thebesii  are 
seen.  a.  The  right  ventricle,  b.  c.  The  cavity  of  the  right  ventricle,  on  the  walls  of 
which  the  columnae  carneae  are  seen;  c  is  placed  in  the  channel  leading  upwards  to  the 
pulmonary  artery,  d.  e.  f.  The  tricuspid  valve;  e  is  placed  on  the  anterior  curtain,  and 
/,  on  the  right  curtain,  g.  The  long  columna  carnea,  to  the  apex  of  which  the  anterior 
and  right  curtains  of  the  tricuspid  valve  are  connected  by  the  chordae  tendineae.  h.  The 
"  long  moderator  band."  t.  The  two  columnae  carneae  of  the  right  curtain,  k.  The  at 
tachtnent  by  chordae  tendinese  of  the  left  limb  of  the  anterior  curtain.  I,  I.  Chordas  ten 
dint<6  of  the  "fixed  curtain"  of  the  valve,  m.  The  valve  of  the  pulmonary  artery.  The 
letter  of  reference  is  placed  on  the  inferior  semilunar  segment,  n.  The  apex  of  the  right 
appendix  auriculas,  o.  The  left  ventricle,  p.  The  ascending  aorta,  q.  Its  arch,  with 
the  three  arterial  trunks  which  arise  from  the  arch.  r.  The  descending  aorta. 

\  Richard  Lower,  M.  D.  "  Tractatus  de  Corde ;  item  de  Motu  et  Colore  Sanguinis," 
1669  His  dissections  were  made  upon  quadrupeds,  and  his  observations  relate  rather 
to  animals  than  to  man. 


RIGHT    VENTRICLE.  479 

tion,  which  was  supposed  by  Lower  to  direct  the  blood  from  the  superior 
cava  into  the  auriculo- ventricular  opening. 

The  Muscali  pectinati  are  small  muscular  columns  situated  in  the  ap 
pendix  auriculae.  They  are  numerous,  and  are  arranged  parallel  with  each 
other ;  hence  their  cognomen,  "  pectinati^  like  the  teeth  of  a  comb. 

The  RIGHT  VENTRICLE  is  triangular  and  prismoid  in  form.  Its  anterior 
side  is  convex,  and  forms  the  larger  proportion  of  the  front  of  the  heart. 
The  posterior  side,  which  is  also  inferior,  is  flat,  and  rests  upon  the  dia- 
phragm ;  the  inner  side  corresponds  with  the  partition  between  the  two 
ventricles,  septum  ventriculorum. 

The  right  ventricle  is  to  be  laid  open  by  making  an  incision  parallel 
wTith,  and  a  little  to  the  right  of,  the  middle  line,  from  the  pulmonary  artery 
in  front,  to  the  apex  of  the  heart,  and  thence  by  the  side  of  the  middle  line 
behind  to  the  auriculo-ventricular  opening. 

It  contains,  to  be  examined,  two  openings,  the  auriculo-ventricular  and 
that  of  the  pulmonary  artery ;  two  apparatus  of  valves,  the  tricuspid  and 
semilunar ;  and  a  muscular  and  tendinous  apparatus  belonging  to  the  tri- 
cuspid valves.  They  may  be  thus  arranged : — 

Auriculo-ventricular  opening, 
Opening  of  the  pulmonary  artery. 

Tricuspid  valves, 
Semilunar  valves. 

Chordae  tendineae, 
Carneae  column®. 

The  Auriculo-ventricular  opening  is  surrounded  by  a  fibrous  ring,  co- 
vered by  the  lining  membrane  of  the  heart.  It  is  the  opening  of  commu- 
nication between  the  right  auricle  and  ventricle. 

The  Opening  oftlie  pulmonary  artery  is  situated  close  to  the  septum 
ventriculorum,  on  the  left  side  of  the  right  ventricle,  and  upon  the  anterior 
aspect  of  the  heart. 

The  Tricuspid  valves  are  three  triangular  folds  of  the  lining  membrane, 
strengthened  by  a  thin  layer  of  fibrous  tissue.  They  are  connected  by 
their  base  around  the  auriculo-ventricular  opening;  and  by  their  sides  and 
apices,  which  are  thickened,  they  give  attachment  to  a  number  of  slender 
tendinous  cords,  called  chordae  tendinese.  The  chorda  tendinece  are  the 
tendons  of  the  thick  musculrr  columns  (columnar  carneee)  which  stand  out 
from  the  walls  of  the  ventricle,  and  serve  as  muscles  to  the  valves.  A 
number  of  these  tendinous  cords  converge  to  a  single  muscular  attach- 
ment. The  tricuspid  valves  prevent  the  regurgitation  of  blood  into  the 
auricle  during  the  contraction  of  the  ventricle,  and  they  are  prevented 
from  being  themselves  driven  back  by  the  chordae  tendineae  and  their 
muscular  attachments. 

This  connexion  of  the  muscular  columns  of  the  heart  to  the  valves  has 
caused  their  division  into  active  and  passive.  The  active  valves  are  the 
tricuspid  and  mitral ;  the  passive,  the  semilunar  and  coronary. 

The  valves  consist,  according  to  Mr.  King,*  of  curtains,  cords,  and 

*  "  Essay  on  the  Safety  Valve  Function  in  the  Right  Ventricle  of  the  Human  Heart," 
by  T.  W.  King.  Guy's  Hospital  Reports,  vol.  ii. 


480  SEMILUNAR    VALVES. 

columns.  The  anterior  valve  or  curtain  is  the  largest,  and  is  so  placed  as 
to  prevent  the  filling  of  the  pulmonary  artery  during  the  distension  of  the 
ventricle.  The  right  valve  or  curtain  is  of  smaller  size,  and  is  situated 
on  the  right  side  of  the  auriculo-ventricular  opening.  The  third  valve,  or 
"fixed  curtain"  is  connected  by  its  cords  to  the  septum  ventriculorum. 
The  cords  (chordae  tendineae)  of  the  anterior  curtain  are  attached,  princi- 
pally, to  a  long  column  (columna  carnea),  which  is  connected  with  the 
"right  or  thin  and  yielding  wall  of  the  ventricle."  From  the  lower  part 
of  this  column  a  transverse  muscular  band,  the  "long  moderator  band"  is 
stretched  to  the  septum  ventriculorum,  or  "solid  wall"  of  the  ventricle. 
The  right  curtain  is  connected,  by  means  of  its  cords,  partly  with  the  long 
column,  and  partly  with  its  own  proper  column,  the  second  column,  which 
is  also  attached  to  the  "yielding  wall"  of  the  ventricle.  A  third  and 
smaller  column  is  generally  connected  with  the  right  curtain.  The  "fixed 
curtain"  is  so  named  from  its  attachment  to  the  "solid  wall"  of  the  ven- 
tricle, by  means  of  cords  only,  without  fleshy  columns. 
.  From  this  arrangement  of  the  valves  it  follows,  that  if  the  right  ven- 
tricle be  over  distended,  the  thin  or  "yielding  wall"  will  give  way,  and 
carry  with  it  the  columns  of  the  anterior  and  right  valves.  The  cords 
connected  with  these  columns  will  draw  down  the  edges  of  the  correspond- 
ing valves,  and  produce  an  opening  between  the  curtains,  through  which 
the  superabundant  blood  may  escape  into  the  auricle,  and  the  ventricle  be 
relieved  from  over-pressure.  This  mechanism  is  therefore  adapted  to 
fulfil  the  "function  of  a  safety  valve" 

The  Columna  carnece  (fleshy  columns)  is  a  name  expressive  of  the 
appearance  of  the  internal  walls  of  the  ventricles,  which  seem  formed  of 
muscular  columns  interlacing  in  almost  every  direction.  They  are  divided, 
according  to  the  manner  of  their  connexion,  into  three  sets.  1.  The 
greater  number  are  attached  by  the  whole  of  one  side,  and  merely  form 
convexities  into  the  cavity  of  the  ventricle.  2.  Others  are  connected  by 
both  extremities,  being  free  in  the  middle.  3.  A  few  (columns  papillares) 
are  attached  by  one  extremity  to  the  walls  of  the  heart,  and  by  the  other 
give  insertion  to  the  chordae  tendines. 

The  Semilunar  valves,  three  in  number,  are  situated  around  the  com- 
mencement of  the  pulmonary  artery,  being  formed  by  a  folding  of  its 
lining  membrane,  strengthened  by  a  thin  layer  of  fibrous  tissue.  They 
are  attached  by  their  convex  borders,  and  free  by  the  concave,  which  are 
directed  upwards  in  the  course  of  the  vessel,  so  that,  during  the  current 
of  the  blood  along  the  artery,  they  are  pressed  against  the  sides  of  the 
cylinder ;  but  if  any  attempt  at  regurgitation  ensue,  they  are  immediately 
expanded,  and  effectually  close  the  entrance  of  the  tube.  The  margins 
of  the  valves  are  thicker  than  the  rest  of  their  extent,  and  each  valve  pre- 
sents in  the  centre  of  this  margin  a  small  fibro-cartilaginous  tubercle, 
called  corpus  Arantii*  which  locks  in  with  the  other  two  during  the 
closure  of  the  valves,  and  secures  the  triangular  space  that  would  other- 
wise be  left  by  the  approximation  of  three  semilunar  folds. 

Between  the  semilunar  valves  and  the  cylinder  of  the  artery  are  three 
pouches,  called  the  pulmonary  sinuses  (sinuses  of  Valsalva).  Similar 

*  Julius  Caesar  Arantius,  Professor  of  Medicine  in  Bologna.  He  was  a  disciple  of 
Vcsalius,  one  of  the  founders  of  modern  anatomy.  His  treatise  "De  Humano  Fcetu" 
was  published  at  Rome,  in  1564. 


LEFT    VENTRICLE.  431 

sinuses  are  situated  behind  the  valves  at  the  commencement  of  the  aorta, 
and  are  larger  and  more  capacious  than  those  of  the  pulmonary  artery. 

The  Pulmonary  artery  commences  by  a  scalloped  border,  correspond- 
ing with  the  three  valves  which  are  attached  along  its  edge.  It  is  con- 
nected to  the  ventricle  by  muscular  fibres,  and  by  the  lining  membrane  of 
the  heart. 

The  LEFT  AURICLE  is  somewhat  smaller,  but  thicker,  than  the  right ; 
of  a  cuboid  form,  and  situated  more  posteriorly.  The  appendix  auricula 
is  constricted  at  its  junction  with  the  auricle,  and  has  a  foliated  appear- 
ance ;  it  is  directed  forwards  towards  the  root  of  the  pulmonary  artery,  to 
which  the  auriculas  of  both  sides  appear  to  converge. 

The  left  auricle  is  to  be  laid  open  by  a  -1-  shaped  incision,  the  horizontal 
section  being  made  along  the  border,  which  is  attached  to  the  base  of  the 
ventricle.  It  presents  for  examination  five  openings,  and  the  muscular 
structure  of  the  appendix ;  these  are — 

Four  pulmonary  veins, 
Auriculo-ventricular  opening, 
Musculi  pectinati. 

The  Pulmonary  veins,  two  from  the  right  and  two  from  the  left  lung, 
open  into  the  corresponding  sides  of  the  auricle.  The  two  left  pulmonary 
veins  terminate  frequently  by  a  common  opening. 

The  auricula-ventricular  opening  is  the  aperture  of  communication  be- 
tween the  auricle  and  ventricle. 

The  Musculi  pectinati  are  fewer  in  number  than  in  the  right  auricle,  and 
are  situated  only  in  the*  appendix  auriculae. 

LEFT  VENTRICLE.  —  The  left  ventricle  is  to  be  opened  by  making  an 
incision  a  little  to  the  left  of  the  septum  ventriculoram,  and  continuing  it 
around  the  apex  of  the  heart  to  the  auriculo-ventricular  opening  behind. 

The  left  ventricle  is  conical,  both  in  external  figure  and  in  the  form  of 
its  internal  cavity.  It  forms  the  apex  of  the  heart,  by  projecting  beyond 
the  right  ventricle,  while  the  latter  has  the  advantage  in  length  towards 
the  base.  Its  \valls  are  about  seven  lines  in  thickness,  vhose  of  the  right 
ventricle  being  about  two  lines  and  a  half. 

It  presents  for  examination,  in  its  interior,  two  openings,  two  valves, 
and  the  tendinous  cords  and  muscular  columns;  they  may  be  thus 
arranged : 

Auriculo-ventricular  opening, 

Aortic  opening. 

Mitral  valves, 

Semilunar  valves. 

Chordae  tendinese, 

Columnae  carneae. 

The  Jluriculo-ventricular  opening  is  a  dense  fibrous  ring,  covered  by 
the  lining  membrane  of  the  heart,  but  smaller  in  size  than  that  of  thp  right 
side. 

The  Mitral  valves  are  attached  around  the  auriculo-ventricular  opening, 
as  are  the  tricuspid  in  the  right  ventricle.  They  are  thicker  than  the  tri- 
cuspid,  and  consist  of  only  two  segments,  of  which  the  larger  is  placed 
41  2F 


482  STRUCTURE    OF    THE    HEAJIT. 

between  the  auriculo-ventricular  opening  and  the  commencement  of  the 
aorta,  and  acts  the  part  of  a  valve  to  that  foramen  during  the  filling  of  the 
ventricle.  The  difference  in  size  of  the  two  valves,  both  being  triangular, 
and  the  space  between  them,  has  given  rise  to  the  idea  of  a  "  bishop's 

Fig.  213.* 


mitre,"  after  which  they  were  named.  These  valves,  like  the  tricuspid, 
are  furnished  with  an  apparatus  of  tendinous  cords,  chordae,  tendinea,  which 
are  attached  to  two  very  large  columns  cornea. 

The  Columns  carnece  admit  of  the  same  arrangement  into  three  kinds, 
as  on  the  right  side.  Those  which  are  free  by  one  extremity,  the  columnar 
papillares,  are  two  in  number,  and  larger  than  those  on  the  opposite  side ; 
one  being  placed  on  the  left  wall  of  the  ventricle,  and  the  other  at  the 
junction  of  the  septum  ventriculorum  with  the  posterior  wall. 

The  Semilunar  valves  are  placed  around  the  commencement  of  the 
aorta,  like  those  of  the  pulmonary  artery ;  they  are  similar  in  structure, 
and  are  attached  to  the  scalloped  border  by  which  the  aorta  is  connected 
with  the  ventricle.  The  tubercle  in  the  centre  of  each  fold  is  larger  than 
those  in  the  pulmonary  valves,  and  it  was  these  that  Arantius  particularly 
described ;  but  the  term  "  corpora  Jlrantii"  is  now  applied  indiscrimi- 
nately to  both.  The  fossae  between  the  semilunar  valves  and  the  cylinder 
of  the  artery  are  larger  than  those  of  the  pulmonary  artery ;  they  are  called 
the  "  sinus  aortici"  (sinuses  of  Valsalva). 

STRUCTURE     OF    THE     HEART. 

The  arrangement  of  the  fibres  of  the  heart  has  been  made  the  subject  of 
careful  investigation  by  Mr.  Searle,  to  whose  article,  "Fibres  of  the  Heart," 

*  The  anatomy  of  the  heart;  the  organ  is  viewed  on  its  left  side.  1.  The  cavity  of 
the  left  auricle.  The  number  is  placed  on  that  portion  of  the  septum  auricularum  cor- 
responding with  the  centre  of  the  fossa  ovalis.  2.  The  cavity  of  the  appendix  auriculse, 
near  the  apex  of  which  are  seen  the  musculi  pectinati.  3.  The  opening  of  the  two 
right  pulmonary  veins.  4.  The  sinus,  into  which  the  left  pulmonary  veins  open.  5. 
The  left  pulmonary  veins.  6.  The  auriculo-ventricular  opening.  7.  The  coronary  vein, 
lying  in  the  aurieulo-ventricular  groove.  8.  The  left  ventricle.  9,  9.  The  cavity  of  the 
left  ventricle;  the  numbers  rest  on  the  septum  ventriculorum.  a.  The  mitral  valve; 
its  flaps  are  connected  by  chordae  tendineae  to  b,  b.  The  columnse  camese.  c,  c.  Fixed 
co'u«ina3  carnese,  forming  part  of  the  internal  surface  of  the  ventricle,  d.  The  arch  of 
ths  aorta,  Irom  the  summit  of  which  the  three  arterial  trunks  of  the  head  and  upper  ex 
tremities  are  seen  arising.  «?.  The  pulmonary  artery.  /.  The  obliterated  ductus  arte- 


FIBRES   OF   THE   VENTRICLES.  433 

m  the  Cyclopaedia  of  Anatomy  and  Physiology,  I  am  indebted  for  the  fol- 
lowing summary  of  their  distribution  : — 

For  the  sake  of  clearness  of  description  the  fibres  of  the  ventricles  have 
been  divided  into  three  layers,  superficial,  middle,  and  internal,  all  of 
which  are  disposed  in  a  spiral  direction  around  the  cavities  of  the  ventri- 
cles. The  mode  of  formation  of  these  three  layers  will  be  best  understood 
by  adopting  the  plan  pursued  by  Mr.  Searle  in  tracing  the  course  of  the 
fibres  from  the  centre  of  the  heart  towards  its  periphery. 

The  left  surface  of  the  septum  ventriculorum  is  formed  by  a  broad  and 
thick  layer  of  fibres,  which  proceed  backwards  in  a  spiral  direction  around 
the  posterior  aspect  of  the  left  ventricle,  and  become  augmented  on  the 
left  side  of  that  ventricle  by  other  fibres  derived  from  the  bases  of  the  two 
columns  papillares.  The  broad  and  thick  band  formed  by  the  fibres  from 
these  two  sources,  curves  around  the  apex  and  lower  third  of  the  left  ven- 
tricle to  the  anterior  border  of  the  septum,  where  it  divides  into  two  bands, 
a  short  or  apicial  band,  and  a  long  or  basial  band. 

The  Short  or  apicial  band  is  increased  in  thickness  at  this  point  by  re- 
ceiving a  layer  of  fibres  (derived  from  the  root  of  the  aorta  and  carneae 
columnee)  upon  its  internal  surface,  from  the  right  surface  of  the  septum 
ventriculorum ;  it  is  then  continued  onwards  in  a  spiral  direction  from  left 
to  right,  around  the  lower  third  of  the  anterior  surface,  and  the  middle 
third  of  the  posterior  surface  of  the  right  ventricle  to  the  posterior  border 
of  the  septum.  From  the  latter  point  the  short  band  is  prolonged  around 
the  posterior  and  outer  border  of  the  left  ventricle  to  the  anterior  surface 
of  the  base  of  that  ventricle,  and  is  inserted  into  the  anterior  border  of  the 
left  auriculo-ventricular  ring,  and  the  anterior  part  of  the  root  of  the  aorta 
and  pulmonary  artery. 

The  Long  or  basial  band,  at  the  anterior  border  of  the  septum,  passes 
directly  backwards  through  the  septum,  (forming  its  middle  layer,)  to  the 
posterior  ventricular  groove,  where  it  becomes  joined  by  fibres  derived 
from  the  root  of  the  pulmonary  artery.  It  then  winds  spirally  around  the 
middle  and  upper  third  of  the  left  ventricle  to  the  anterior  border  of  the 
septum,  where  it  is  connected  by  means  of  its  internal  surface  with  the 
superior  fibres  derived  from  the  aorta,  which  form  part  of  the  right  wall 
of  the  septum.  From  this  point  it  is  continued  around  the  upper  third 
of  the  anterior  and  posterior  surface  of  the  right  ventricle  to  the  posterior 
border  of  the  septum,  where  it  is  connected  with  the  fibres  constituting 
the  right  surface  of  the  septum  ventriculorum.  At  the  latter  point  the 
fibres  of  this  band  begin  to  be  twisted  upon  themselves,  like  the  strands 
of  a  rope,  the  direction  of  the  twist  being  from  below  upwards.  This 
arrangement  of  fibres  is  called  by  Mr.  Searle  "  the  rope ;"  it  is  continued 
spirally  upwards,  forming  the  brim  of  the  left  ventricle,  to  the  anterior 
surface  of  the  base  of  that  ventricle,  where  the  twisting  of  the  fibres  ceases. 
The  long  band  then  curves  inwards  towards  the  septum,  and  spreads  out 
upon  the  left  surface  of  the  septum  into  the  broad  and  thick  layer  of  fibres 
with  which  this  description  commenced. 

The  most  inferior  of  the  fibres  of  the  left  surface  of  the  septum  ventri- 
culorum, after  winding  spirally  around  the  internal  surface  of  the  apex  of 
the  left  ventricle,  so  as  to  close  its  extremity,  form  a  small  fasciculus, 

riosus ;  the  letter  is  placed   in  the  cleft  formed  by  the  bifurcation  of  the  pulmonary  a:. 
•.cry.     g.  The    left    pulmonary  artery,     h.  The   right  ventricle,     i.  The   point  of  the- 
appendix  of  the  right  auricle. 


484  STRUCTURE    OF    THE    HEART. 

which  is  excluded  from  the  interior  of  the  ventricle,  and  expands  in  a 
radiated  manner  over  the  surface  of  the  heart,  constituting  its  superficial 
layer  of  fibres.  The  direction  of  these  fibres  is,  for  the  most  part,  oblique, 
passing  from  left  to  right  on  the  anterior  and  from  right  to  left  on  the  pos- 
terior surface  of  the  heart,  becoming  more  longitudinal  near  its  base,  and 
terminating  oy  being  inserted  into  the  fibrous  rings  of  the  auriculo-ventri 
cular  openings,  and  of  the  pulmonary  artery  and  aorta.  Over  the  righ 
ventricle  the  superficial  fibres  are  increased  in  number  by  the  addition  of 
accessory  fibres  from  the  right  surface  of  the  septum,  which  pierce  the 
middle  layer,  and  take  the  same  direction  with  the  superficial  fibres  from 
the  apex  of  the  left  ventricle,  and  of  other  accessory  fibres  from  the  sur- 
face of  both  ventricles. 

From  this  description  it  will  be  perceived,  that  the  superficial  layer  of 
fibres  is  very  scanty,  and  is  pretty  equally  distributed  over  the  surface  of 
both  ventricles.  The  middle  layer  of  both  ventricles  is  formed  by  the  two 
bands,  short  and  long.  But  the  internal  layer  of  the  two  ventricles  is  very 
differently  constituted :  that  of  the  left  is  formed  by  the  spiral  expansion 
of  the  fibres  of  the  rope,  and  of  the  two  columns  papillares ;  that  of  the 
right  remains  to  be  described.  The  septum  ventriculorum  also  consists 
of  three  layers,  a  left  layer,  the  radiated  expansion  of  the  rope  arid  carnese 
columnae ;  a  middle  layer ,  the  long  band ;  and  a  right  layer ,  belonging  to 
the  proper  wall  of  the  right  ventricle,  and  continuous  both  in  front  and 
behind  with  the  long  band,  and  in  front  also  with  the  short  band,  and  with 
the  superficial  layer  of  the  right  ventricle. 

The  Internal  layer  of  the  right  ventricle  is  formed  by  fasciculi  of  fibres 
which  arise  from  the  right  segment  of  the  root  of  the  aorta,  from  the  entire 
circumference  of  the  root  of  the  pulmonary  artery,  and  from  the  bases  of 
the  columnse  papillares.  The  fibres  from  the  root  of  the  aorta,  associated 
with  some  from  the  carnese  columnse,  constitute  a  layer  which  passes  ob- 
liquely forwards  upon  the  right  side  of  the  septum.  The  superior  fibres 
coming  directly  from  the  aorta  join  the  internal  surface  of  the  long  band 
at  the  anterior  border  of  the  septum,  wrhile  the  lower  two-thirds  of  the 
layer  are  continuous  with  the  internal  surface  of  the  short  band,  some  of 
its  fibres  piercing  that  band  to  augment  the  number  of  superficial  fibres. 
The  fibres  derived  from  the  root  of  the  pulmonary  artery,  conjoined  with 
those  from  the  base  of  one  of  the  columnse  papillares,  curve  forwards  from 
their  origin,  and  wind  obliquely  downwards  and  backwards  around  the 
internal  surface  of  the  wall  of  the  ventricle  to  the  posterior  border  of  the 
septum,  where  they  become  continuous  with  the  long  band,  directly  that 
it  has  passed  backwards  through  the  septum. 

Fibres  of  the  Jluricles. —  The  fibres  of  the  auricles  are  disposed  in  two 
layers,  external  and  internal.  The  internal  layer  is  formed  of  fasciculi 
which  arise  from  the  fibrous  rings  of  the  auriculo-ventricular  openings  and 
proceed  upwards  to  enlace  with  each  other,  and  constitute  the  appendices 
auricularum.  These  fasciculi  are  parallel  in  their  arrangement,  and  in  the 
appendices  form  projections  and  give  rise  to  the  appearance  which  is  de- 
nominated musculi  pectinati.  In  their  course  they  give  ofF  branches  which 
connect  adjoining  fasciculi,  and  form  a  columnar  interlacement  between 
them. 

External  Layer. — The  fibres  of  the  right  auricle  having  completed  the 
appendix,  wind  from  left  to  right  around  the  right  border  of  this  auricle, 
and  along  its  anterior  aspect,  beneath  the  appendix,  to  the  anterior  surface 


ORGANS    OF    RESPIRATION    AND    VOICE.  485 

of  the  septum.  From  the  septum  they  are  continued  to  the  anterior  sur- 
face of  the  left  auricle,  where  they  separate  into  three  bands,  superior,  an- 
terior, and  posterior.  The  superior  band  proceeds  onwards  to  the  appen- 
dix, and  encircles  the  apex  of  the  auricle.  The  anterior  band  passes  to 
the  left,  beneath  the  appendix,  and  winds  as  a  broad  layer  completely 
around  the  base  of  the  auricle,  and  through  the  septum  to  the  root  of  the 
aorta,  to  which  it  is  partly  attached,  and  from  this  point  is  continued  on- 
wards to  the  appendix,  where  its  fibres  terminate  by  interlacing  with  the 
musculi  pectinati.  The  posterior  band  crosses  the  left  auricle  obliquely  to 
its  posterior  part,  and  winds  from  left  to  right  around  its  base,  encircling 
the  openings  of  the  pulmonary  veins ;  some  of  its  fibres  are  lost  on  the 
surface  of  the  auricle,  others  are  continued  onwards  to  the  base  of  the 
aorta ;  and  a  third  set,  forming  a  small  band,  are  prolonged  along  the 
anterior  edge  of  the  appendix  to  its  apex,  where  they  are  continuous  with 
the  superior  band.  The  septum  auricularum  has  four  sets  of  fibres  enter- 
ing into  its  formation  ;  1.  The  fibres  arising  from  the  auriculo- ventricular 
rings  at  each  side  ;  2.  Fibres  arising  from  the  root  of  the  aorta,  which  pas? 
upwards  to  the  transverse  band,  and  to  the  root  of  the  superior  cava ;  3. 
Those  fibres  of  the  anterior  band  that  pass  through  the  lower  part  of  the 
septum  in  their  course  around  the  left  auricle ;  and,  4.  A  slender  fascicu- 
lus, which  crosses  through  the  septum  from  the  posterior  part  of  the  right 
auriculo-ventricular  ring  to  the  left  auricle. 

It  will  be  remarked,  from  this  description,  that  the  left  auricle  is  consi- 
derably thicker  and  more  muscular  than  the  right. 

Vessels  and  Nerves. — The  Arteries  supplying  the  heart  are  the  anterior 
and  posterior  coronary.  The  Veins  accompany  the  arteries,  and  empty 
themselves  by  the  common  coronary  vein  into  the  right  auricle.  The 
lymphatics  terminate  in  the  glands  about  the  root  of  the  heart.  The  nerves 
of  the  heart  are  derived  from  the  cardiac  plexuses,  which  are  formed  b^ 
communicating  filaments  from  the  sympathetic  and  pneumogastric. 

ORGANS   OF   RESPIRATION  AND   VOICE. 

The  organs  of  respiration  are  the  two  lungs,  with  their  air-tube,  the 
trachea,  to  the  upper  part  of  which  is  adapted  an  apparatus  of  cartilages, 
constituting  the  organ  of  voice,  or  larynx. 

THE    LARYNX. 

The  Larynx  is  situated  at  the  fore  part  of  the  neck,  between  the  trachea 
and  the  base  of  the  tongue.  It  is  a  short  tube,  having  an  hour-glass  form, 
and  is  composed  of  cartilages,  ligaments,  muscles,  vessels,  nerves,  and 
mucous  membrane. 

The  Cartilages  are  the — 

Thyroid,  Two  cuneiform, 

Cricoid,  Epiglottis. 

Two  arytenoid, 

The  Thyroid  (Sujsos — sT&tf,  like  a  shield)  is  the  largest  cartilage  of  the 

Jarynx :  it  consists  of  two  lateral  portions,  or  ales,  which  meet  at  an  angle 

in  front,  and  form  the  projection  which  is  known  by  the  name  of  pomum 

Mami.     In  tke  male,  after  puberty,  the  angle  of  union  of  the  two  alas  is 

41* 


48ft  CARTILAGES    OF    THE    LARYNX. 

acute  ;  in  the  female,  and  before  puberty  in  the  male,  it  is  obtuse.  Where 
the  pomum  Adami  is  prominent,  a  bursa  mucosa  is  often  found  between 
it  and  the  skin. 

Each  ala  is  quadrilateral  in  shape,  and  forms  a  rounded  border  poste- 
riorly, which  terminates  above,  in  the  superior  comu,  and  below,  in  the 
inferior  cornu.  Upon  the  side  of  the  ala  is  an  oblique  line,  or  ridge,  di- 
rected downwards  and  forwards,  and  bounded  at  each  extremity  by  a 
tubercle.  Into  this  line  the  sterno-thyroid  muscle  is  inserted ;  and  from  it 
the  thyro-hyoid  and  inferior  constrictor  take  their  origin.  In  the  receding 
angle,  formed  by  the  meeting  of  the  two  alae  upon  the  inner  side  of  the 
cartilage,  and  near  its  lower  border,  are  attached  the  epiglottis,  the  chordae 
vocales,  the  thyro-arytenoid,  and  thyro-epiglottidean  muscles. 

The  Cricoid  (x^'xo? — sTSog,  like  a  ring)  is  a  ring  of  cartilage,  narrow  in 
front,  and  broad  behind,  where  it  is  surmounted  by  two  rounded  surfaces, 
which  articulate  with  the  arytenoid  cartilages.  At  the  middle  line,  poste- 
riorly, is  a  vertical  ridge  which  gives  attachment  to  the  ossophagus,  and 
on  each  side  of  the  ridge  are  the  depressions  which  lodge  the  crico-aryte- 
noidei  postici  muscles.  On  either  side  of  the  ring  is  a  glenoid  cavity, 
which  articulates  with  the  inferior  cornu  of  the  thyroid  cartilage. 

The  Jlrytenoid  cartilages  (dgwalva,*  a  pitcher),  two  in  number,  are  tri- 
angular and  prismoid  in  form.  They  are  broad  and  thick  below  where 
they  articulate  with  the  upper  border  of  the  cricoid  cartilage ;  pointed 
above,  and  prolonged  by  two  small  pyriform  cartilages,  cornicula  laryngis 
(capitula  Santorini),  which  are  curved  inwards  and  backwards,  and  they 
each  present  three  surfaces,  anterior,  posterior,  and  internal.  The  poste- 
rior surface  is  concave,  and  lodges  part  of  the  arytenoideus  muscle ;  the 
internal  surface  is  smooth,  and  forms  part  of  the  lateral  wall  of  the  larynx ; 
the  anterior  or  external  surface  is  rough  and  irregular,  and  gives  attach- 
ment to  the  chorda  vocalis,  thyro-arytenoideus,  crico-arytenoideus  lateralis 
and  posticus,  and,  above  these,  to  the  base  of  the  cuneiform  cartilage. 

The  Cuneiform  cartilages  are  two  small  cylinders  of  fibro- cartilage, 
about  seven  lines  in  length,  and  enlarged  at  each  extremity.  By  the  lower 
end,  or  base,  the  cartilage  is  attached  to  the  middle  of  the  external  surface 
of  the  arytenoid,  and  by  its  upper  extremity  forms  a  prominence  in  the 
border  of  the  aryteno-epiglottidean  fold  of  membrane.  They  are  some- 
times wanting. 

In  the  male,  the  cartilages  of  the  larynx  are  more  or  less  ossified,  par- 
ticularly in  old  age. 

The  Epiglottis  (sviy'b.wrls,  upon  the  tongue)  is  a  fibro-cartilage  of  a 
yellowish  colour,  studded  with  a  number  of  small  mucous  glands,  which 
are  lodged  in  shallow  pits  upon  its  surface.  It  is  shaped  like  a  cordate 
leaf,  and  is  placed  immediately  in  front  of  the  opening  of  the  larynx,  which 
it  closes  completely  when  the  larynx  is  drawn  up  beneath  the  base  of  the 
tongue.  It  is  attached  by  its  point  to  the  receding  angle,  between  the  two 
alae  of  the  thyroid  cartilage. 

Ligaments. — The  Ligaments  of  the  larynx  are  numerous,  and  may  be 
arranged  into  four  groups :  1.  Those  which  articulate  the  thyroid  with  the 
os  hyoides.  2.  Those  which  connect  it  with  the  cricoid.  3.  Ligaments 
of  the  arytenoid  cartilages.  4.  Ligaments  of  the  epiglottis. 

*  This  derivation  has  reference  to  the  appearance  of  both  cartilages  taken  together 
«nd  covered  by  mucous  membrane.  In  animals,  which  were  the  principal  subjects  of 
dissection  among  the  ancients,  the  opening  of  the  larynx  with  the  arytenoid  cartilaa^ 
bears  a  striking  resemblance  to  the  mouth  of  a  pitcher  having  a  large  spout. 


LIGAMENTS    OF    THE    LARYNX. 


487 


Fig.  214* 


1.  The  ligaments  which  connect  the  thyroid  cartilage  with  the  os  hyoides 
are  three  in  number : — 

The  two  Thyro-hyoidean  ligaments  pass  between  the  superior  cornua  of 
the  thyroid  and  the  extremities  of  the  greater  cornua  of  the  os  hyoides :  a 
sesamoid  bone  or  cartilage  is  found  in  each. 

The  Thyro-hyoidean  membrane  is  a  broad  membranous  layer,  occupying 
the  entire  space  between  the  upper  border  of  the  thyroid  cartilage  and  the 
upper  border  of  the  os  hyoides.  It  is  pierced  by  the  superior  laryngeal 
nerve  and  artery. 

2.  The  ligaments  connecting  the  thyroid  to  the  cricoid  cartilage  are  also 
three  in  number : — 

Two  Capsular  ligaments,  with  their  synovial  membranes,  which  form 
the  articulation  between  the  inferior  cornua  of  the  thyroid  and  the  sides 
of  the  cricoid ;  and  the  crico-thyroidean  membrane. 
The  crico-thyroidean  membrane  is  a  fan-shaped 
layer  of  elastic  tissue,  thick  in  front  (middle  crico- 
thyroidean  ligament)  and  thinner  at  each  side  (late- 
ral crico-thyroidean  ligament).  It  is  attached  by 
its  apex  to  the  lower  border  and  receding  angle1) 
of  the  thyroid  cartilage,  and  by  its  expanded  mar- 
gin to  the  upper  border  of  the  cricoid  and  base  of 
the  arytenoid  cartilage.  .Superiorly  it  is  continuous 
with  the  inferior  margin  of  the  chorda  vocalis. 
The  front  of  the  crico-thyroidean  membrane  is 
crossed  by  a  small  artery,  the  inferior  laryngeal, 
and  is  the  spot  selected  for  the  operation  of  laryn- 
gotomy.  Laterally  it  is  covered  in  by  the  crico- 
thyroidei  and  crico-arytenoidei  laterales  muscles. 

3.  The  ligaments  of  the  arytenoid  cartilages  are 
six  in  number : — 

Two  Capsular  ligaments,  with  synovial  mem- 
branes, which  articulate  the  arytenoid  cartilages 
with  the  cricoid  ;  and  the  superior  and  inferior 
thyro-arytenoid  ligaments.  The  superior  thyro-arytenoid  ligaments  are 
two  thin  bands  of  elastic  tissue  which  are  attached  in  front  to  the  receding 
angle  of  the  thyroid  cartilage,  and  behind  to  the  anterior  and  inner  border 
of  each  arytenoid  cartilage.  The  lower  border  of  this  ligament  constitutes 
the  upper  boundary  of  the  ventricle  of  the  larynx.  The  inferior  thyro- 

*  A  vertical  section  of  the  larynx,  showing  its  ligaments.  1.  The  body  of  the  os  hyo- 
ides. 2.  Its  great  cornu.  3.  Its  lesser  cornu.  4.  The  ala  of  the  thyroid  cartilage.  5. 
The  superior  cornu.  6.  Its  inferior  cornu.  7.  The  pomum  Adami.  8,  8.  The  thyro- 
hyoidean  membrane;  the  opening  in  the  membrane  immediately  above  the  most  pos- 
terior of  the  numerals  is  for  the  passage  of  the  superior  laryngeal  nerve  and  artery.  9. 
The  thyro-hyoidean  ligament;  the  numeral  is  placed  immediately  above  the  sesamoid 
bone  or  cartilage  which  exists  in  this  ligament,  a.  The  epiglottis,  b.  The  hyo-epiglottic 
ligament,  c.  The  thyro-epiglottic  ligament,  d.  The  arytenoid  cartilage ;  its  inner  surface. 
«.  The  outer  angle  of  the  base  of  the  arytenoid  cartilage.  /.  The  corniculum  laryngis. 
g.  The  cuneiform  cartilage,  h.  The  superior  thyro-arytenoid  ligament,  i.  The  inferior 
thyro-arytenoid  ligament,  or  chorda  vocalis;  the  elliptical  space  between  the  two  thyro- 
arytenoid  ligaments  is  that  of  the  ventricle  of  the  larynx,  k.  The  cricoid  cartilage.  /. 
The  lateral  portion  of  the  crico-thyroidean  membrane,  m.  The  central  portion  of  the 
same  membrane,  n.  The  upper  ring  of  the  trachea,  which  is  received  within  the  ring 
of  the  cricoid  cartilage,  o.  Section  of  the  isthmus  of  the  thyroid  gland,  p,  p.  The  levn 
tor  glanilulcB  thyroideeB. 


488  MUSCLES    OF    THE    LARYNX. 

arylenoid  ligaments,  or  chorda  vocales,  are  thicker  than  the  superior,  and 
like  them  composed  of  elastic  tissue.  Each  ligament  is  attached  in  front 
to  the  receding  angle  of  the  thyroid  cartilage,  and  behind  to  the  anterior 
angle  of  the  base  of  the  arytenoid.  The  interior  border  of  the  chorda  vo- 
calis  is  continuous  with  the  lateral  expansion  of  the  crico-thyroid  ligament. 
The  superior  border  forms  the  lower. boundary  of  the  ventricle  of  the  la- 
rynx. The  space  between  the  two  chordae  vocales  is  the  glottis  or  rima 
glottidis. 

4.  The  ligaments  of  the  epiglottis  are  five  in  number,  namely,  three 
glosso-epiglottic,  hyo-epiglottic,  and  thyro-epiglottic. 

p.    215*  '^e  g^ofso-epiglottic  ligaments  (frsena  epiglottidis) 

are  three  folds  of  mucous  membrane,  which  connect 
the  anterior  surface  of  the  epiglottis  with  the  root  of 
the  tongue.  The  middle  of  these  contains  elastic  tis- 
sue. The  hyo-epiglottic  ligament  is  a  band  of  elastic 
tissue  passing  between  the  anterior  aspect  of  the  epi- 
glottis near  its  apex,  and  the  upper  margin  of  the  body 
of  the  os  hyoides.  The  thyro-epiglottic  ligament  is  a 
long  and  slender  fasciculus  of  elastic  tissue,  which 
embraces  the  apex  of  the  epiglottis,  and  is  inserted 
into  the  receding  angle  of  the  thyroid  cartilage  imme- 
diately below  the  anterior  fissure  and  above  the  attach- 
ment of  the  chorda;  vocales. 
Muscles. — The  muscles  of  the  larynx  are  eight  in  number:  the  five 
larger  are  the  muscles  of  the  chordse  vocales  and  rima  glottidis;  the  three 
smaller  are  muscles  of  the  epiglottis. 

The  five  muscles  of  the  chords  vocales  and  rima  glottidis  are  the — 

Crico-thyroid, 

Crico-arytenoideus  posticus, 
Crico-arytenoideus  lateralis, 
Thyro-arytenoideus, 
Arytenoideus. 

The  Crico-thyroid  muscle  arises  from  the  anterior  surface  of  the  cricoid 
cartilage,  and  passes  obliquely  outwards  and  backwards  to  be  inserted 
into  the  lower  and  inner  border  of  the  ala  of  the  thyroid  as  far  back  as  its 
inferior  cornu. 

The  Crico-arytenoideus  posticus  arises  from  the  depression  on  the  pos- 
terior surface  of  the  cricoid  cartilage,  and  passes  upwards  and  outwards 
to  be  inserted  into  the  outer  angle  of  the  base  of  the  arytenoid. 

The  Crico-arytenoideus  lateralis  arises  from  the  upper  border  of  the 
side  of  the  cricoid,  and  passes  upwards  and  backwards  to  be  inserted  into 
the  outer  angle  of  the  base  of  the  arytenoid  cartilage. 

The  Thyro-arytenoideus  arises  from  the  receding  angle  of  the  thyroid 
cartilage,  close  to  the  outer  side  of  the  chorda  vocalis,  and  passes  back- 
wards parallel  with  the  cord,  to  be  inserted  into  the  base  and  outer  surface 
of  the  arytenoid  cartilage. 

*  A  posterior  view  of  the  larynx.  1.  The  thyroid  cartilage,  its  right  ala.  2.  One  of 
us  ascending  oornua.  3.  One  of  the  descending  cornua.  4,  7.  The  cricoid  cartilage. 
5.  5.  The  arytenoid  cartilages.  6.  The  arytenoideus  muscle,  consisting  of  oblique  and 
transverse  fasciculi.  7.  The  crico-arytenoidei  postici  muscles.  8.  The  epiglottis 


MUSCLES    OF    THE    LARYNX.  489 

The  Arytenoideus  muscle  occupies  the  posterior  con- 
iave  surface  of  the  arytenoid  cartilages,  between  which  Flg>  216'* 
•t  is  stretched.  It  consists  of  three  planes  of  trans- 
verse and  oblique  fibres ;  hence  it  was  formerly  consi- 
dered as  several  muscles,  under  the  names  of  transversi 
and  obliqui. 

The  three  muscles  of  the  epiglottis  are  the — 

Thyro-epiglottideus, 
Aryteno-epiglottideus  superior, 
Aryteno-epiglottideus  inferior. 

The  Thyro-epiglottideus  appears  to  be  formed  by  the 
upper  fibres  of  the  thyro-arytenoideus  muscle :    they 
spread  out  upon  the  external  surface  of  the  sacculus 
laryngis  and  in  the  aryteno-epiglottidean  fold  of  mucous  membrane,  in 
which  they  are  lost ;  a  few  of  the  anterior  fibres  being  continued  onwards 
to  the  side  of  the  epiglottis. 

The  Aryteno-epiglottideus  superior  consists  of  a  few  scattered  fibres, 
which  pass  forwards  in  the  fold  of  mucous  membrane  forming  the  lateral 
boundary  of  the  entrance  into  the  larynx,  from  the  apex  of  the  arytenoid 
cartilage  to  the  side  of  the  epiglottis. 

The  jlryteno-epiglottideus  inferior.  —  This  muscle,  described  by  Mr. 
Hilton,  and  closely  connected  with  the  sacculus  laryngis,  may  be  found 
by  raising  the  mucous  membrane  immediately  above  the  ventricle  of  the 
larynx.  It  arises  by  a  narrow  and  fibrous  origin  from  the  arytenoid  carti- 
lage, just  above  the  attachment  of  the  chorda  vocalis ;  and  passing  for- 
wards, and  a  little  upwards,  expands  over  the  upper  half,  or  two-thirds  of 
the  sacculus  laryngis,  and  is  inserted  by  a  broad  attachment  into  the  side 
of  the  epiglottis. 

Actions. — From  a  careful  examination  of  the  muscles  of  the  larynx,  Mr. 
Bishopf  concludes,  that  the  crico-arytenoidei  postici  open  the  glottis, 
while  all  the  rest  close  it.  The  arytenoideus  approximates  the  arytenoid 
cartilages  posteriorly,  and  the  crico-arytenoidei  laterales  and  thyro-aryte- 
noidei  anteriorly ;  the  latter,  moreover,  close  the  glottis  mesially.  The 
crico-thyroidei  are  tensors  of  the  chorda  vocales,  and  these  muscles, 
together  with  the  thyro-arytenoidei,  regulate  the  tension,  position,  and 
vibrating  length  of  the  vocal  cords. 

The  crico-thyroid  muscles  effect  the  tension  of  the  chordae  vocales  by 
rotating  the  cricoid  on  the  inferior  cornua  of  the  thyroid  ;  by  this  action 
the  anterior  portion  is  drawn  upwards  and  made- to  approximate  the  infe- 
rior border  of  the  thyroid,  while  the  posterior  and  superior  border  of  the 
cricoid,  together  with  the  arytenoid  cartilages,  is  carried  backwards.  The 
crico-arytenoidei  postici  separate  the  chorda?  vocales  by  drawing  the  ary- 
tenoid cartilages  outwards  and  downwards.  The  crico-arytenoidei  late- 
rales,  by  drawing  the  outer  angles  of  the  arytenoid  cartilages  forwards, 
approximate  the  anterior  angles  to  which  the  chordae  vocales  are  attached. 
The  thyro-arytenoidei  draw  the  arytenoid  cartilages  forwards,  and,  by  their 

*  A  side  view  of  the  larynx,  one  ala  of  the  thyroid  cartilage  has  been  removed.  1. 
The  remaining  ala  of  the  thyroid  cartilage.  2.  One  of  the  arytenoid  cartilages.  3.  One 
of  the  cornicuia  laryngis.  4.  The  cricoid  cartilage.  5.  The  crico-arytenoideus  posticu* 
muscle.  G.  The  crico-arytenoideus  lateralis.  7.  The  thyro-arytenoideus.  8.  The  crico- 
thyroidean  membrane.  9.  One  half  of  the  epiglottis.  10.  The  upper  part  of  the  trachs* 

t  Cyclopaedia  of  Anatomy  and  Physiology,  art.  Larynx 


490  MUCOUS    MEMBRANE    OF   THE    LARYNX. 

connexion  with  the  chordse  vocales,  act  upon  the  whole  length  of  those 
cords. 

The  thyro-epiglottideus  acts  principally  by  cpmpressing  the  glands  of 
the  sacculus  laryngis  and  the  sac  itself:  by  its  attachment  to  the  epiglottis 
it  would  act  feebly  upon  that  valve.  The  aryteno-epiglottideus  superior 
serves  to  keep  the  mucous  membrane  of  the  sides  of  the  opening  of  the 
glottis  tense,  when  the  larynx  is  drawn  upwards  and  the  opening  closed 
by  the  epiglottis.  Of  the  aryteno-epiglottideus,  the  "functions  appear  to 
be,"  writes  Mr.  Hilton,  "  to  compress  the  subjacent  glands  which  open 
into  the  pouch ;  to  diminish  the  capacity  of  that  cavity,  and  change  its 
form ;  and  to  approximate  the  epiglottis  and  the  arytenoid  cartilage." 

Mucous  Membrane. — The  aperture  of  the  larynx  is  a  triangular  or  cord- 
iform  opening,  broad  in  front  and  narrow  behind ;  bounded  anteriorly 
by  the  epiglottis,  posteriorly  by  the  arytenoideus  muscle,  and  on  either 
side  by  a  fold  of  mucous  membrane  stretched  between  the  side  of  the  epi- 
glottis and  the  apex  of  the  arytenoid  cartilage.  On  the  margin  of  this 
aryteno-epiglottidean  fold  the  cuneiform  cartilage  forms  a  prominence  more 
or  less  distinct.  The  cavity  of  the  larynx  is  divided  into  two  parts  by  an 
oblong  constriction  produced  by  the  prominence  of  the  chorda?  vocales. 
That  portion  of  the  cavity  which  lies  above  the  constriction  is  broad  and 
triangular  above,  and  narrow  below ;  that  which  is  below  it,  is  narrow 
above  and  broad  and  cylindrical  below,  the  circumference  of  the  cylinder 
corresponding  with  the  ring  of  the  cricoid ;  while  the  space  included  by 
the  constriction  is  a  narrow,  triangular  fissure,  the  glottis  orrirna  glottidis. 
The  form  of  the  glottis  is  that  of  an  isosceles  triangle,  bounded  on  the 
sides  by  the  chorda?  vocales  and  inner  surface  of  the  arytenoid  cartilages, 
and  behind  by  the  arytenoideus  muscle.  Its  length  is  greater  in  the  male 
than  in  the  female,  and  in  the  former  measures  somewhat  less  than  an  inch. 
Immediately  above  the  prominence  caused  by  the  chorda  vocalis,  and  ex- 
tending nearly  its  entire  length  on  each  side  of  the  cavity  of  the  larynx,  is 
an  elliptical  fossa,  the  ventricle  of  the  larynx.  This  fossa  is  bounded  be- 
low by  the  chorda  vocalis,  which  it  serves  to  isolate,  and  above  by  a  border 
of  mucous  membrane  folded  upon  the  lower  edge  of  the  superior  thyro- 
arytenoid  ligament.  The  whole  of  the  cavity  of  the  larynx,  with  its  pro- 
minences and  depressions,  is  lined  by  mucous  membrane,  which  is  con- 
tinuous superiorly  with  that  of  the  mouth  and  pharynx,  and  inferiorly  is 
prolonged  through  the  trachea  and  bronchial  tubes  into  the  lungs.  In  the 
ventricles  of  the  larynx  the  mucous  membrane  forms  a  csecal  pouch  of  va- 
riable size,  termed  by  Mr.  Hilton  the  sacculus  laryngis*  The  sacculus 

*  This  sac  was  described  by  Mr.  Hilton  before  he  was  aware  that  it  had  already 
been  pointed  out  by  the  older  anatomists.  I  myself  made  a  dissection,  which  I  still 
possess,  of  the  same  sac  in  an  enlarged  state,  during:  the  month  of  August,  1837,  without 
any  knowledge  either  of  Mr.  Hilton's  labours  or  Morgagni's  account.  The  sac  projected 
considerably  above  the  upper  border  of  the  thyroid  cartilage,  and  the  extremity  had 
been  snipped  off  on  one  side  in  the  removal  of  the  muscles.  The  larynx  was  presented 
to  me  by  Dr.  George  Moore  of  Camberwell ;  he  had  obtained  it  from  a  child  who  died 
of  bronchial  disease ;  and  he  conceived  that  this  peculiar  disposition  of  the  mucous 
membrane  might  possibly  explain  some  of  the  symptoms  by  which  the  case  was  ac- 
companied. Cruveilhier  made  the  same  observation  in  equal  ignorance  of  Morgagni's 
description,  for  we  read  in  a  note  at  page  677,  vol.  ii.  of  his  Jlnatomie  Descriptive. — "J'ai 
ru  pour  la  premiere  fois  cette  arriere  cavite'  chez  un  individu  effecte  de  phthisic  laryngee. 
oii  elle  6tait  tres-developpee.  Je  fis  des  recherches  sur  le  larynx  d'autres  individu*,  et 
je  trouvai  que  cette  disposition  etait  constante.  Je  ne  savais  pas  alors  que  Morgagui 


TRACHEA.  491 

Jaryngis  is  directed  upwards,  sometimes  extending  as  high  as  the  upper 
border  of  the  thyroid  cartilage,  and  occasionally  above  that  border.  \Vhen 
dissected  from  the  interior  of  the  larynx  it  is  found  covered  by  the  aryteno- 
epiglottideus  muscle  and  a  fibrous  membrane,  \vhich  latter  is  attached  to 
the  superior  thyro-arytenoid  ligament  below ;  to  the  epiglottis  in  front ; 
and  to  the  upper  border  of  the  thyroid  cartilage  above.  If  examined  from 
the  exterior  of  the  larynx,  it  will  be  seen  to  be  covered  by  the  thyro-epi- 
glottideus  muscle.  On  the  surface  of  its  mucous  membrane  are  the  open- 
ings of  sixty  or  seventy  small  follicular  glands,  which  are  situated  in  the 
submucous  tissue,  and  give  to  its  external  surface  a  rough  and  ill-dissected 
appearance.  The  secretion  from  these  glands  is  intended  for  the  lubrica- 
tion of  the  chordce  vocales,  and  is  directed  upon  them  by  two  small  val- 
vular folds  of  mucous  membrane,  which  are  situated  at  the  entrance  of  the 
sacculus. 

Glands.  —  The  bodies  known  as  the  glands  of  the  larynx,  namely,  the 
epiglottic  and  the  arytenoid,  are  very  improperly  named.  The  former  is 
a  mass  of  areolo-fibrous  and  adipose  tissue,  situated  in  the  triangular  space 
between  the  front  surface  of  the  apex  of  the  epiglottis,  the  hyo-epiglotti- 
dean  and  the  thyro-hyoidean  ligament.  The  latter  is  the  body  which 
forms  a  prominence  in  the  aryteno-epiglottidean  fold  of  mucous  mem- 
brane, and  has  been  described  among  the  cartilages  as  the  cuneiform  car- 
tilage. 

Vessels  and  Nerves.  —  The  Arteries  of  the  larynx  are  derived  from  the 
superior  and  inferior  thyroid.  The  Nerves  are  the,  superior  laryngeal  and 
recurrent  laryngeal ;  both  branches  of  the  pneumogastric.  The  two  nerves 
communicafe  with  each  other  freely  ;  but  the  superior  laryngeal  is  distri- 
buted principally  to  the  mucous  membrane  at  the  entrance  of  the  larynx ; 
the  recurrent,  to  the  muscles. 

THE    TRACHEA. 

The  TRACHEA  extends  from  opposite  the  fifth  cervical  vertebra  to  oppo- 
site the  third  dorsal,  where  it  divides  into  the  two  bronchi.  The  right 
bronchus,  larger  than  the  left,  passes  off  nearly  at  right  angles  to  the  upper 
part  of  the  corresponding  lung.  The  left  descends  obliquely,  and  passes 
beneath  the  arch  of  the  aorta,  to  reach  the  left  lung. 

The  Trachea  is  composed  of — 

Fibro-cartilaginous  rings, 
Fibrous  membrane, 
Mucous  membrane, 
Longitudinal  elastic  fibres, 
Muscular  fibres, 
Glands. 

The  Fibro-cartilaginous  rings  are  from  fifteen  to  twenty  in  number,  and 
extend  for  two-thirds  around  the  cylinder  of  the  trachea.  They  are  defi- 
cient at  the  posterior  part,  where  the  tube  is  completed  by  fibrous  mem- 
brane. The  last  ring  has  usually  a  triangular  form  in  front.  The  rings 

avail  indiqu6  et  faitre  presenter  la  m6me  disposition."  Cruveilhier  compares  its  forn- 
very  aptly  to  a  "Phrygian  casque,"  and  Morgagni  s  figure,  Advers.  1.  Epist.  Anat.  3.  plau» 
2.  fig.  4,  has  the  same  appearance.  Buf  neither  of  these  anatomists  notice  the  folliculai 
glands  described  by  Mr.  Hilton. 


492  THE    LUNGS. 

are  connected  to  each  other  by  a  membrane  of  yellow  elastic  fibrous  tissue, 
which  in  the  space  between  the  extremities  of  the  cartilages,  posteriorly, 
forms  a  distinct  layer. 

The  Longitudinal  elastic  fibres  are  situated  immediately  beneath  the 
mucous  membrane  on  the  posterior  part  of  the  trachea,  and  enclose  the 
entire  cylinder  of  the  bronchial  tubes  to  their  terminations. 

The  Muscular  fibres  form  a  thin  layer,  extending  transversely  between 
the  extremities  of  the  cartilages.  On  the  posterior  surface  they  are  covered 
in  by  an  areolo-fibrous  lamella,  in  which  are  lodged  the  tracheal  glands. 
These  are  small  flattened  ovoid  bodies,  situated  in  great  number  between 
the  fibrous  and  muscular  layers  of  the  membranous  portion  of  the  trachea, 
and  also  between  the  two  layers  of  elastic  fibrous  tissue  connecting  the 
rings.  They  pour  their  secretion  upon  the  mucous  membrane. 

Thyroid  Gland. 

The  thyroid  gland  or  body  is  one  of  those  organs  which  it  is  difficult  to 
classify  from  the  absence  of  any  positive  knowledge  with  regard  to  its 
function.  It  is  situated  upon  the  trachea,  and  in  an  anatomical  arrange- 
ment may  therefore  be  considered  in  this  place,  although  bearing  no  part 
in  the  function  of  respiration. 

This  gland  consists  of  two  lobes,  which  are  placed  one  on  each  side  of 
the  trachea,  and  are  connected  with  each  other  by  means  of  an  isthmus, 
which  crosses  its  upper  rings.  There  is  considerable  variety  in  the  situa- 
tion and  breadth  of  the  isthmus,  which  should  be  recollected  in  the  per- 
formance of  operations  upon  the  trachea.  In  structure  it  is  composed, 
according  to  Mr.  Simon,*  of  a  dense  aggregation  of  minute  and  inde- 
pendent membranous  cavities  enclosed  by  a  plexus  of  capillary  ves- 
sels, and  connected  together  by  areolo-fibrous  tissue.  The  cavities  are 
filled  with  fluid,  in  which  are  found  cyto-blasts  and  cells  ;  the  latter  mea- 
suring y;^  of  an  inch  in  diameter.  In  young  animals  the  cyto-blasts  lie 
in  contact  with  the  internal  wall  of  the  cavities,  and  constitute  a  kind  of 
tesselated  epithelium.  The  gland  is  larger  in  young  subjects  and  in 
females,  than  in  the  adult  and  males.  It  is  the  seat  of  an  enlargement 
called  bronchocele,  goitre,  or  the  Derbyshire  neck. 

A  muscle  is  occasionally  found  connected  with  its  upper  border  or  with 
its  isthmus ;  and  attached,  superiorly,  to  the  body  of  the  os  hyoides,  or  to 
the  thyroid  cartilage.  It  was  named  by  Soemmering  the  "  levator  glandula 
thyroidcce;"  fig.  214,  p.  487. 

Vessels  and  Nerves. — It  is  abundantly  supplied  with  blood  by  the  supe- 
rior and  inferior  thyroid  arteries.  Sometimes  an  additional  artery  is 
derived  from  the  arteria  innominata,  and  ascends  upon  the  front  of  the 
trachea,  to  be  distributed  to  the  gland.  The  wounding  of  the  latter  ves- 
sel, in  tracheotomy,  might  be  fatal  to  the  patient.  The  nerves  are  derived 
from  the  superior  laryngeal  and  sympathetic. 

THE    LUNGS. 

The  lungs  are  two  conical  organs,  situated  one  on  each  side  of  the 
chest,  embracing  the  heart,  and  separated  from  each  other  by  that  organ 

*  The  Comparative  Anatomy  of  the  Thyroid  Gland.  Philosophical  Transactions, 
'844 


THE    LUNGS.  493 

and  by  a  membranous  partition,  the  mediastinum.  On  the  external  or 
thoracic  side  they  are  convex,  and  correspond  with  the  form  of  the  cavity 
of  the  chest ;  internally  they  are  concave,  to  receive  the  convexity  of  the 
heart.  Superiorly  they  terminate  in  a  tapering  cone,  which  extends  above 
the  level  of  the  first  rib,  and  inferiorly  they  are  broad  and  concave,  and 
rest  upon  the  convex  surface  of  the  diaphragm.  Their  posterior  border 
is  rounded  and  broad,  the  anterior  sharp,  and  marked  by  one  or  two  deep 
fissures,  and  the  inferior  border  which  surrounds  the  base  is  also  sharp. 
The  colour  of  the  lungs  is  pinkish-grey,  mottled,  and  variously  marked 
with  black.  The  surface  is  figured  with  irregularly  polyhedral  outlines, 
which  represent  the  lobules  of  the  organ,  and  the  area  of  each  of  these 
polyhedral  spaces  is  crossed  by  lighter  lines. 

Fig.  217.* 


Each  lung  is  divided  into  two  lobes,  by  a  long  and  deep  fissure,  which 
extends  from  the  posterior  surface  of  the  upper  part  of  the  organ,  down- 
wards and  forwards  to  near  the  anterior  angle  of  its  base.  In  the  right 
lung  the  upper  lobe  is  subdivided  by  a  second  fissure,  which  extends  ob- 
liquely forwards  from  the  middle  of  the  preceding  to  the  anterior  border 
of  the  organ,  and  marks  off  a  small  triangular  lobe. 

The  right  lung  is  larger  than  the  left,  in  consequence  of  the  inclination 
of  the  heart  to  the  left  side.  It  is  also  shorter,  from  the  great  convexity 

*  Anatomy  of  the  heart  and  lungs.  1.  The  right  ventricle ;  the  vessels  to  the  left  of 
the  number  are  the  middle  coronary  artery  and  veins ;  and  those  to  its  right,  the  ante- 
rior coronary  artery  and  veins.  2.  The  left  ventricle.  3.  The  right  auricle.  4.  The 
left  auricle.  5.  The  pulmonary  artery.  6.  The  right  pulmonary  artery.  7.  The  left 
pulmonary  artery.  8.  The  remains  of  the  ductus  arteriosus.  9.  The  arch  of  the  aorta. 
10.  The  superior  vena  cava.  11.  The  arteria  innominata,  and  in  front  of  it  the  right 
vena  innorninata.  12.  The  right  subclavian  vein,  and,  behind  it,  its  corresponding  ar- 
teiy.  13.  The  right  common  carotid  artery  and  vein.  14.  The  left  vena  innorninata, 
15.  The  left  caroti  i  artery  and  vein.  16.  The  left  subclavian  vein  and  artery.  17.  The 
trachea.  18.  The  right  bronchus.  19.  The  left  bronchus.  20,  20.  The  pulmonary 
veins;  18,  20,  form  the  root  of  the  right  lung;  and  7,  19,  20,  the  root  of  the  left.  2L 
The  superior  lobe  of  the  right  lung.  22.  Its  middle  lobe.  23.  Its  inferior  lobe.  ,24 
The  superior  lobe  of  the  left  lung.  25.  Its  inferior  lobe. 

42 


494  BRONCHIAL   TUBES. 

cf  the  liver,  which  presses  the  diaphragm  upwards  upon  the  right  side  of 
the  chest  considerably  above  the  level  of  the  left ;  and  has  three  lobes 
The  left  lung  is  smaller,  has  but  two  lobes,  but  is  longer  than  the  right. 

Each  lung  is  retained  in  its  place  by  its  root,  which  is  formed  by  the 
pulmonary  artery,  pulmonary  veins  and  bronchial  tubes,  together  with  the 
bronchial  vessels  and  pulmonary  plexuses  of  nerves.  The  large  vessels 
of  the  root  of  each  lung  are  arranged  in  a  similar  order  from  before,  back- 
wards, on  both  sides,  viz. 

Pulmonary  veins, 
Pulmonary  artery, 
Bronchus. 

From  above,  downwards,  on  the  right  side,  this  order  is  exactly  re- 
versed ;  but  on  the  left  side,  the  bronchus  has  to  stoop  beneath  the  arch 
of  the  aorta,  which  alters  its  position  to  the  vessels.  They  are  thus  dis- 
posed on  the  two  sides : — 

Right.  Left. 

Bronchus,  Artery, 

Artery,  Bronchus, 

Veins.  Veins. 

Structure. — The  lungs  are  composed  of  the  ramifications  of  the  bron- 
chial tubes  which  terminate  in  intercellular  passages  and  air-cells,  of  the 
ramifications  of  the  pulmonary  artery  and  veins,  bronchial  arteries  and 
veins,  lymphatics  and  nerves;  the  whole  of  these  structures,  being  held 
together  by  areolo-fibrous  tissue,  constitute  the  parenchyma.  The  paren- 
chyma of  the  lungs,  when  examined  on  the  surface  or  by  means  of  a  sec- 
tion, is  seen  to  consist  of  small  polyhedral  divisions,  or  lobules,  which  are 
connected  to  each  other  by  an  inter-lobular  areolar  tissue.  These  lobules 
again  consist  of  smaller  lobules,  and  the  latter  are  formed  by  a  cluster  of 
air-cells,  in  the  parietes  of  which  the  capillaries  of  the  pulmonary  artery 
and  pulmonary  veins  are  distributed. 

Bronchial  Tubes. — The  two  bronchi  proceed  from  the  bifurcation  of  the 
trachea  to  their  corresponding  lungs.  The  right  takes  its  course  nearly 
at  right  angles  with  the  trachea,  and  enters  the  upper  part  of  the  right 
lung ;  while  the  left,  longer  and  smaller  than  the  right,  passes  obliquely 
benealh  the  arch  of  the  aorta,  and  enters  the  lung  at  about  the  middle  of 
its  root.  Upon  entering  the  lungs  they  divide  into  two  branches,  and 
each  of  these  divides  and  subdivides  dichotomously  to  their  ultimate  ter- 
mination in  the  intercellular  passages  and  air-cells. 

According  to  Mr.  Rainey,*  the  bronchial  tubes  continue  to  diminish  in 
size  until  they  attain  a  diameter  of  ^  to  •£$  of  an  inch,  and  arrive  within 
|  of  an  inch  of  the  surface  of  the  lung.  They  then  become  changed  in 
structure,  and  are  continued  onwards  in  the  midst  of  air-cells,  under  the 
name  of  intercellular  passages.  Lastly,  the  intercellular  passages,  after 
several  bifurcations,  terminate,  each  by  a  cascal  extremity  or  air-cell.  The 
intercellular  passages  are  at  first  cylindrical  like  the  bronchial  tubes,  but 
soon  become  irregular  in  shape  from  the  great  number  of  air-cells  which 
open  into  them  on  all  sides.  The  air-cells  are  small,  irregular  in  shape, 
and,  most  frequently,  four-sided  cavities,  separated  by  thin  septa,  and 
communicating  freely  with  the  intercellular  passages,  and  sparingly  with 

*  Meclico-Cbirurgical  Transactions,  vol.  xxviii. 


BRONCHIAL    TUBES  -  PLEURJE.  495 

the  bronchial  tubes.    .  The  air-cells  composing  a  lobule  also  communicate 
freely  with  each  other. 

The  bronchial  tubes,  after  the  cessation  of  the  fibre-cartilaginous  plates, 
are  composed  of  fibrous  membrane  (constructed  of  longitudinal  and  cir- 
cular fibres)  and  mucous  membrane,  the  latter  being  invested  by  a  ciliated 
columnar  epithelium.  At  the  termination  of  these  tubes  the  mucous  mem- 
brane and  epithelium  cease  abruptly,  and  the  fibrous  membrane,  very  thin 
and  transparent,  is  continued  onwards  through  the  intercellular  passages 
and  air-cells.  The  same  change  takes  place  in  the  structure  of  the  parie- 
tes,  where  the  air-cells  open  directly  into  the  bronchial  tubes. 

The  capillaries  of  the  lungs  form  plexuses  which  occupy  the  walls  and 
septa  of  the  air-cells  and  the  walls  of  the  intercellular  passages,  but  are 
not  continued  into  the  bronchial  tubes.  The  septa  between  the  cells  con- 
sist of  a  single  layer  of  the  capillary  plexus  enclosed  in  a  fold  of  the 
fibrous  lining  membrane.  The  cells  of  the  central  parts  of  the  lung  are 
.nost  vascular,  and  at  the  same  time  smallest,  while  those  of  the  periphery 
are  less  vascular  and  larger. 

The  pigmentary  matter  of  the  lungs  is  contained  in  the  air-cells,  as  well 
as  in  the  areolo-fibrous  tissue  of  the  inter-lobular  spaces  and  of  the  blood- 
vessels. 

The  Pulmonary  artery,  conveying  the  dark  and  impure  venous  blood 
to  the  lungs,  terminates  in  capillary  vessels,  which  form  a  minute  network 
in  the  parieties  of  the  intercellular  passages  and  air-cells,  and  then  con- 
verge to  form  the  pulmonary  veins,  by  which  the  arterial  blood,  purified 
in  its  passage  through  the  capillaries,  is  returned  to  the  left  auricle  of  the 
heart. 

The  Bronchial  arteries,  branches  of  the  thoracic  aorta,  ramify  on  the 
parieties  of  the  bronchial  tubes,  while  the  venous  blood  is  returned  by  the 
bronchial  veins  to  the  vena  azygos. 

The  Lymphatics,  commencing  on  the  surface  and  in  the  substance  of 
the  lungs,  terminate  in  the  bronchial  glands.  These  glands,  very  numerous 
and  often  of  large  size,  are  placed  'at  the  roots  of  the  lungs,  around  the 
bronchi,  and  at  the  bifurcation  of  the  trachea.  In  early  life  they  resemble 
lymphatic  glands  in  other  situations  ;  but  in  old  age,  and  often  in  the 
adult,  are  quite  black,  and  filled  with  carbonaceous  matter,  and  occasion- 
ally with  calcareous  deposits. 

The  Nerves  are  derived  from  the  pneumogastric  and  sympathetic.  They 
form  two  plexuses  :  antenor  pulmonary  plexus,  situated  upon  the  front  of 
the  root  of  the  lungs,  and  composed  chiefly  of  filaments  from  the  great 
cardiac  plexus  ;  and  posterior  pulmonary  plexus,  on  the  posterior  aspect 
of  the  root  of  the  lungs,  composed  principally  of  branches  from  the  pneu 
mogastric.  The  branches  from  these  plexuses  follow  the  course  of  the 
bronchial  tubes,  and  are  distributed  to  the  intercellular  passages  and  air 


p  L  EU  RJE. 


Each  lung  is  enclosed,  and  its  structure  maintained,  by  a  serous  mem 
brane,  the  pleura,  which  invests  it  as  far  as  the  root,  and  is  then  reflected 
upon  the  parietes  of  the  chest.  That  portion  of  the  membrane  which  is 
in  relation  with  the  lung  is  called  pleura  pulmonalis,  and  that  in  contact 
with  the  parietes,  pleura  costalis.  The  reflected  portion,  besides  forming 
the  internal  lining  to  the  ribs  and  intercostal  muscles,  also  covers  the  dia- 
phragm and  the  thoracic  surface  of  the  vessels  at  the  root  of  the  neck 


496  MEDIASTINUM ABDOMEN. 

The  pleura  must  be  dissected  from  off  the  root  of  the  lung,  to  see  the 
vessels  by  which  it  is  formed,  and  the  pulmonary  plexuses. 

MEDIASTINUM. 

The  approximation  of  the  two  reflected  pleurae  in  the  middle  line  of  the 
thorax  forms  a  septum,  which  divides  the  chest  into  the  two  pulmonary 
cavities.  This  is  the  mediastinum.  The  two  pleurae  are  not,  however, 
in  contact  with  each  other  at  the  middle  line  in  the  formation  of  the  medi- 
astinum, but  have  a  space  between  them  which  contains  all  the  viscera  of 
the  chest  with  the  exception  of  the  lungs.  The  mediastinum  is  divided 
into  the  anterior,  middle,  and  posterior. 

The  interior  mediastinum  is  a  triangular  space,  bounded  in  front  by 
the  sternum,  and  on  each  side  by  the  pleura.  It  contains  a  quantity  of 
loose  areolar  tissue,  in  which  are  found  some  lymphatic  vessels  passing 
upwards  from  the  liver,  the  remains  of  the  thymus  gland,  the  origins  of  the 
sterno-hyoid,  sterno-thyroid,  and  triangularis  sterni  muscles,  and  the  in- 
ternal mammary  vessels  of  the  left  side. 

The  Middle  mediastinum  contains  the  heart  enclosed  in  its  pericardium ; 
the  ascending  aorta ;  the  superior  vena  cava ;  the  bifurcation  of  the  trachea ; 
the  pulmonary  arteries  and  veins ;  and  the  phrenic  nerves. 

The  Posterior  mediastinum  is  bounded  behind  by  the  vertebral  column, 
in  front  by  the  pericardium,  and  on  each  side  by'the  pleura.  It  contains 
the  descending  aorta ;  the  greater  and  lesser  azygos  veins ;  the  superior 
intercostal  vein ;  the  thoracic  duct ;  the  oesophagus  and  pneumogastric 
nerves,  and  the  great  splanchnic  nerves. 


ABDOMEN. 

The  abdomen  is  the  inferior  cavity  of  the  trunk  of  the  body ;  it  is 
bounded  in  front  and  at  the  sides  by  the  lower  ribs  and  abdominal  mus- 
cles ;  behind,  by  the  vertebral  column  and  abdominal  muscles ;  above,  by 
the  diaphragm ;  and,  below,  by  the  pelvis :  and  contains  the  alimentary 
canal,  the  organs  subservient  to  digestion,  viz.  the  liver,  pancreas,  and 
spleen ;  and  the  organs  of  excretion,  the  kidneys,  with  the  supra-renal 
capsules. 

Regions. — For  convenience  of  description  of  the  viscera,  and  of  refer- 
ence to  the  morbid  affections  of  this  cavity,  the  abdomen  is  divided  into 
certain  districts  or  regions.  Thus,  if  two  transverse  lines  be  carried  around 
the  body,  the  one  parallel  with  the  inferior  convexities  of  the  ribs,  the  other 
with  the  highest  points  of  the  crests  of  the  ilia,  the  abdomen  will  be  divided 
into  three  zones.  Again,  if  a  perpendicular  line  be  drawn  at  each  side, 
from  the  cartilage  of  the  eighth  rib  to  the  middle  of  Poupart's  ligament, 
the  three  primary  zones  will  each  be  subdivided  into  three  compartments 
or  regions,  a  middle  and  two  lateral. 

The  middle  region  of  the  upper  zone  being  immediately  over  the  su.all 
end  of  the  stomach,  is  called  epigastric  (M  yaarfy,  over  the  stomach). 
The  two  lateral  regions  being  under  the  cartilages  of  the  ribs  are  called 
lypochondriac  (iiru  x°v<$£oi,  under  the  cartilages).  The  middle  region  of 
the  middle  zone  is  the  umbilical ;  the  two  lateral,  the  lumbar.  The  middle 
region  of  the  inferior  zone  is  the  hypogastric  (viro  yaff<n^,  below  the  sto- 
mach) ;  and  the  two  lateral,  the  iliac.  In  addition  to  these  divisions  we 


ABDOMINAL    VISCERA.  497 

Fig.  218* 


•-mploy  the  terra  inguinal  region,  in  reference  to  the  vicinity  of  Poupart'o 
ligament. 

Position  of  the  Viscera.  —  In  the  upper  zone  will  be  seen  the  liver,  ex- 
tending across  from  the  right  to  the  left  side  ;  the  stomach  and  spleen  on 
the  left,  and  the  pancreas  and  duodenum  behind.  In  the  middle  zone  is 
the  transverse  portion  of  the  colon,  with  the  upper  part  of  the  ascending 
and  descending  colon,  omentum,  small  intestines,  mesentery,  and,  behind, 
the  kidneys  and  supra-renal  capsules  In  the  inferior  zone  is  the  lower 
part  of  the  omentum  and  small  intestines,  the  csecum,  ascending  and  de- 
scending colon  with  the  sigmoid  flexure,  and  ureters. 

The  smooth  and  polished  surface,  which  the  viscera  and  panetes  of  the 
abdomen  present,  is  due  to  the  peritoneum,  which  should  in  the  next 
place  be  studied 

PERITONEUM. 

The  Peritoneum  (*££ITSIV£IV,  to  extend  around)  is  a  serous  membrane, 
and  therefore  a  shut  sac :  a  single  exception  exists  in  the  human  subject 
to  this  character,  viz.  in  the  female,  where  the  peritoneum  is  perforated  by 
the  open  extremities  of  the  Fallopian  tubes,  and  is  continuous  with  their 
mucous  lining. 

*  The  viscera  of  the  abdomen  in  situ.  1,  1.  The  iiapa  of  the  abdominal  parietea 
turned  aside.  2.  The  liver,  its  left  lobe.  3.  Its  right  lo"be.  4.  The  fundus  of  the  gall- 
bladder. 5.  The  round  ligament  of  the  liver,  issuing  from  the  cleft  of  the  longitudinal 
fissure,  and  passing  along  the  parietes  of  the  abdomen  to  the  umbilicus.  6.  Part  of  the 
broad  ligament  of  the  liver.  7.  The  stomach.  8.  Its  pyloric  end.  9.  The  commence 
ment  of  the  duodenum,  a.  The  lower  extremity  of  the  spleen,  b,  b.  The  greater  omen- 
tum. c,  c.  The  small  intestines,  d.  The  caecum,  e.  The  appendix  caeci.  /.  The  as 
cending  colon,  g,  g.  The  transverse  colon,  h.  The  descending  colon,  t.  The  sigmoid 
flexure  of  the  colon,  k.  Appendices  epiploicae  connected  with  the  sigmoid  flexure,  i. 
Three  ridges,  representing  the  cords  of  the  urachus  and  the  umbilical  arteries  ascending 
o  *he  umbilicus  m.  Part  of  the  under  surface  of  the  diaphragm. 

42*  2« 


PERITONEUM. 


Fig.  219.*  The  simplest  idea  that  can  be  given 

of  a  serous  membrane,  which  may 
apply  equally  to  all,  is,  that  it  invests 
the  viscus  or  viscera,  and  is  then  re- 
flected upon  the  parietes  of  the  con- 
taining cavity.  If  the  cavity  contain 
only  a  single  viscus,  the  consideration 
of  the  serous  membrane  is  extremely 
simple.  But  in  the  abdomen,  where 
there  are  a  number  of  viscera,  the  se- 
rous membrane  passes  from  one  to  the 
other  until  it  has  invested  the  whole, 
before  it  is  reflected  on  the  parietes. 
Hence  its  reflexions  are  a  little  more 
complicated. 

In  tracing  the  reflexions  of  the  pe- 
ritoneum in  the  middle  line,  we  com- 
mence with  the  diaphragm,  which  is 
lined  by  two  layers,  one  from  the 
parietes  in  front,  anterior,  and  one 
from  the  parietes  behind,  posterior. 
These  two  layers  of  the  same  mem- 
brane, at  the  posterior  part  of  the 
diaphragm,  descend  to  the  upper  sur- 
face of  the  liver,  forming  the  coronary 
and  lateral  ligaments  of  the  liver. 
They  then  surround  the  liver,  one 
going  in  front,  the  other  behind  that 

viscus,  and,  meeting  at  its  under  surface,  pass  to  the  stomach,  forming  the 
lesser  omentum.  They  then,  in  the  same  manner,  surround  the  stomach, 
and,  meeting  at  its  lower  border,  descend  for  some  distance  hi  front  of 
the  intestines,  and  return  to  the  transverse  colon,  forming  the  great  omen- 
tum ;  they  then  surround  the  transverse  colon,  and  pass  directly  back- 
wards to  the  vertebral  column,  forming  the  transverse  meso-colon.  Here 
the  two  layers  separate ;  the  posterior  ascends  in  front  of  the  pancreas  and 
aorta,  and  returns  to  the  posterior  part  of  the  diaphragm,  where  it  becomes 
the  posterior  layer  with  which  we  commenced.  .  The  anterior  descends, 
invests  all  the  small  intestines,  and  returning  to  the  vertebral  column, 
forms  the  mesentery.  It  then  descends  into  the  pelvis  in  front  of  the 

*  The  reflexions  of  the  peritoneum.  D.  The  diaphragm.  S.  The  stomach.  C.  The 
transverse  colon.  D.  The  transverse  duodenum.  P.  The  pancreas.  I.  The  small  in- 
testines. R.  The  rectum.  B.  The  urinary  bladder.  1.  The  anterior  layer  of  the  peri- 
toneum, lining  the  under  surface  of  the  diaphragm.  2.  The  posterior  layer.  3.  The 
coronary  ligament,  formed  by  the  passage  of  these  two  layers  to  the  posterior  border  of 
the  liver.  4.  The  lesser  omentum  ;  the  two  layers  passing  from  the  under  surface  of 
the  liver  to  the  lesser  curve  of  the  stomach.  5.  The  two  layers  meeting  at  the  greater 
curve,  then  passing  downwards  and  returning  upon  themselves,  forming  (6)  the  greater 
omentum.  7.  The  transverse  meso-colon.  8.  The  posterior  layer  traced  upwards  in 
front  of  D,  the  transverse  duodenum,  and  P,  the  pancreas,  to  become  continuous  with 
the  posterior  layer  (2).  9.  The  foramen  of  Winslow;  the  dotted  line  bounding  this 
foramen  inferiorly  marks  the  course  of  the  hepatic  artery  forwards,  to  enter  between 
fjc  layers  of  the  lesser  omentum.  10.  The  mesentery  encircling  the  small  intestine. 
.1.  The  recto-vesical  fold,  formed  by  the  descending  anterior  layer.  12.  The  anterior 
Inyor  traced  upwards  upon  the  internal  surface  of  the  abdominal  parietes  to  the  layei 
( 1)  vv.th  which  the  examination  commenced. 


PERITONEUM — DUPLICATURES.  499 

rectum,  which  it  holds  in  its  place  by  means  of  a  fold  called  meso -rectum, 
forms  a  pouch,  the  recto-vesical  fold,  between  the  rectum  and  bladder, 
ascends  upon  the  posterior  surface  of  the  bladder,  forming  its  false  liga 
ments,  and  returns  upon  the  anterior  parietes  of  the  abdomen  to  the  dia 
phragm,  whence  we  first  traced  it. 

In  the  female,  after  descending  into  the  pelvis  in  front  of  the  rectum,  it 
is  reflected  upon  the  posterior  surface  of  the  vagina  and  uterus.  It  then 
descends  on  the  anterior  surface  of  the  uterus,  and  forms  at  either  side 
the  broad  ligaments  of  that  organ.  From  the  uterus  it  ascends  upon  the 
posterior  surface  of  the  bladder  and  anterior  parietes  of  the  abdomen,  and 
is  continued,  as  in  the  male,  to  the  diaphragm. 

In  this  way  the  continuity  of  the  peritoneum,  as  a  whole,  is  distinctly 
shown,  and  it  matters  not  where  the  examination  commence  or  where  it 
terminate,  still  the  same  continuity  of  surface  will  be  discernible  through- 
out. If  we  trace  it  from  side  to  side  of  the  abdomen,  we  may  commence 
at  the  umbilicus ;  we  then  follow  it  outwards  lining  the  inner  side  of  the 
parietes  to  the  ascending  colon ;  it  surrounds  that  intestine ;  it  then  sur- 
rounds the  small  intestine,  and  returning  on  itself  forms  the  mesentery. 
It  then  invests  the  descending  colon,  and  reaches  the  parietes  on  the  op- 
posite side  of  the  abdomen,  whence  it  may  be  traced  to  the  exact  point 
from  which  we  started. 

The  viscera,  which  are  thus  shown  to  be  invested  by  the  peritoneum  in 
its  course  from  above  downwards,  are  the — 

Liver,  Small  intestines, 

Stomach,  Pelvic  viscera. 

Transverse  colon, 

The  folds,  formed  between  these  and  between  the  diaphragm  and  the 
liver,  are — 

(Diaphragm.) 
Broad,  coronary,  and  lateral  ligaments. 

(Liver.) 
Lesser  omentum. 

(Stomach.) 

Greater  omentum. 

(Transverse  colon.) 

Transverse  meso-colon. 

Mesentery, 
Meso-rectum, 
Recto-vesical  fold, 
False  ligaments  of  the  bladder. 

And  in  the  female,  the — 

Broad  ligaments  of  the  uterus. 

The  ligaments  of  the  liver  will  be  described  with  that  organ. 

The  Lesser  omentum  is  the  duplicature  which  passes  between  the  liver 
and  the  upper  border  of  the  stomach.  It  is  extremely  thin,  excepting  ar 
its  right  border,  where  it  is  free,  and  contains  between  its  layers,  the— 


500  FORAMEN    OF   WliNSLOW — OMENTUM. 

Hepatic  artery,  Hepatic  plexus  of  nerves, 

Ductus  communis  choledochus,  Lymphatics. 

Portal  vein. 

These  structures  are  enclosed  in  a  loose  areolar  tissue,  called  Glissorfs 
capsule*  The  relative  position  of  the  three  vessels  is,  the  artery  to  the 
left,  the  duct  to  the  right,  and  the  vein  between  and  behind. 

If  the  finger  be  introduced  behind  this  right  border  of  the  lesser  omentum, 
it  will  be  situated  in  an  opening  called  the  foramen  of  Winslow. \  In  front 
of  the  finger  will  lie  the  right  border  of  the  lesser  omentum ;  behind  it  the 
diaphragm,  covered  by  the  ascending  or  posterior  layer  of  the  peritoneum ; 
below,  the  hepatic  artery,  curving  forwards  from  the  creliac  axis ;  and 
above,  the  lobus  Spigelii.  These,  therefore,  are  the  boundaries  of  the  fo- 
ramen of  Winslow,  which  is  nothing  more  than  a  constriction  of  the  gene- 
ral cavity  of  the  peritoneum  at  this  point,  arising  out  of  the  necessity  for 
the  hepatic  and  gastric  arteries  to  pass  forwards  from  the  coeliac  axis  to 
reach  their  respective  viscera. 

If  air  be  blown  through  the  foramen  of  Winslow,  it  will  descend  behind 
the  lesser  omentum  and  stomach  to  the  space  between  the  descending  and 
ascending  pair  of  layers,  forming  the  great  omentum.  This  is  sometimes 
called  the  lesser  cavity  of  the  peritoneum,  and  that  external  to  the  foramen 
the  greater  cavity ;  in  which  case  the  foramen  is  considered  as  the  means 
of  communication  between  the  two.  There  is  a  great  objection  to  this 
division,  as  it  might  lead  the  inexperienced  to  believe  that  there  were 
really  two  cavities.  There  is  but  one  only,  the  foramen  of  Winslow  being 
merely  a  constriction  of  that  one,  to  facilitate  the  communication  between 
the  nutrient  arteries  and  the  viscera  of  the  upper  part  of  the  abdomen. 

The  Great  omentum  consists  of  four  layers  of  peritoneum,  the  two 
which  descend  from  the  stomach,  and  the  same  two,  returning  upon  them- 
selves to  the  transverse  colon.  A  quantity  of  adipose  substance  is  depo- 
sited around  the  vessels  which  ramify  through  its  structure.  It  would 
appear  to  perform  a  double  function  in  the  economy.  1st.  Protecting  the 
intestines  from  cold;  and,  2dly.  Facilitating  the  movement  of  the  intes- 
tines upon  each  other  during  their  vermicular  action. 

The  Transverse  meso-colon  (f^sVog,  middle,  being  attached  to  the  middle 
of  the  cylinder  of  the  intestine)  is  the  medium  of  connexion  between  the 
transverse  colon  and  the  posterior  wall  of  the  abdomen.  It  also  affords  to 
the  nutrient  arteries  a  passage  to  reach  the  intestine,  and  encloses  between 
its  layers,  at  the  posterior  part,  the  transverse  portion  of  the  duodenum. 

The  Mesentery  (fAsVov  IWs^ov,  being  connected  to  the  middle  of  the  cylin- 
der of  the  small  intestine)  is  the  medium  of  connexion  between  the  small 
intestines  and  the  posterior  wall  of  the  abdomen.  It  is  oblique  in  its  di- 
rection, being  attached  to  the  posterior  wall,  from  the  left  side  of  the  second 
lumbar  vertebra  to  the  right  iliac  fossa.  It  retains  the  small  intestines  in 
their  places,  and  gives  passage  to  the  mesenteric  arteries,  veins,  nerves, 
and  lymphatics. 

The  Meso-redum,  in  like  manner,  retains  the  rectum  in  connexion  with 
the  front  of  the  sacrum.  Besides  this,  there  are  some  minor  folds  in  th«. 

*  Francis  Glisson,  Professor  of  Medicine  in  the  University  of  Cambridge.  His  work, 
"  De  Anatomia  Hepatis,"  was  published  in  1654. 

t  Jacob  Benignus  Winslow  :  his  "  Exposition  Anatomique  de  la  Structure  du  Corp. 
liumair"  was  published  in  Paris  in  1732. 


ALIMENTARY    CANAL.  501 

pelvis,  as  the  recto-vesical  fold,  the  false  ligaments  of  the  bladder,  and  the 
broad  ligaments  of  the  uterus. 

The  Appendices  epiploica  are  small  irregular  pouches  of  the  peritoneum, 
filled  with  fat,  and  situated  like  fringes  upon  the  laro-e  intestine. 

Three  other  duplicatures  of  the  peritoneum  are  situated  in  the  sides  of 
the  abdomen ;  they  are  the  gastro-phrenic  ligament,  the  gastro-splenic 
omentum,  the  ascending  and  descending  meso-colon.  The  gastro-phrenic 
ligament  is  a  small  duplicature  of  the  peritoneum,  which  descends  from 
the  diaphragm  to  the  extremity  of  the  oesophagus,  and  lesser  curve  of  the 
stomach.  The  gastro-splenic  omentum  is  the  duplicature  which  connects 
the  spleen  to  the  stomach.  The  ascending  meso-colon  is  the  fold  which 
connects  the  upper  part  of  the  ascending  colon  with  the  posterior  wall  of 
the  abdomen ;  and  the  descending  meso-colon,  that  which  retains  the  sig- 
moid  flexure  in  connexion  with  the  abdominal  wall. 

Structure  of  Serous  Membrane. — Serous  membrane  consists  of  two 
layers,  an  external  or  areolo-fibrous  layer,  and  an  internal  layer  or  epithe- 
lium. The  areolo-fibrous  layer  upon  its  outer  surface  is  rough  and  vascu- 
lar, and  adherent  to  surrounding  structures ;  but  on  its  inner  or  free  sur- 
face is  dense  and  smooth,  and  deficient  of  vessels.  The  smooth  and 
brilliant  surface  of  serous  membrane  is  due  to  a  distinct  epithelium,  com- 
posed of  laminae  of  cells,  and  flattened  polyhedral  scales  with  central  nuclei, 
like  the  epiderma  and  epithelium  of  mucous  membrane.  Henle  has  also 
observed  this  structure,  which  may  be  demonstrated  with  a  good  micro- 
scope, on  the  surface  of  all  the  serous  membranes  of  the  body,  upon  the 
surface  of  the  lining  membrane  of  arteries  and  veins,  and  on  synovial 
membranes. 

The  general  characters  of  a  serous  membrane  are  its  resemblance  to  a 
shut  sac,  and  its  secretion  of  a  peculiar  fluid,  resembling  the  serum  of  the 
blood  ;  but  the  former  of  these  characters  is  not  absolutely  essential  to  the 
identity  of  a  serous  membrane  ;  for,  as  we  have  shown  above,  the  perito- 
neum in  the  female  is  perforated  by  the  extremities  of  the  Fallopian  tubes ; 
while  in  some  aquatic  reptiles  there  is  a  direct  communication  between  its 
cavity  arid  the  medium  in  which  they  live. 

From  the  variable  nature  of  the  secretion  of  these  membranes,  they 
have  been  divided  into  two  classes,  the  true  serous  membranes,  viz.  the 
arachnoid,  pericardiujn,  pleura,  peritoneum,  and  tunicae  vaginales,  which 
pour  out  a  secretion  containing  but  a  small  portion  of  albumen ;  and  the 
synovial  membranes  and  bursae,  which  secrete  a  fluid  containing  a  larger 
quantity  of  albumen. 

ALIMENTARY     CANAL. 

The  Alimentary  canal  is  a  musculo-membranous  tube,  extending  from 
he  mouth  to  the  anus.  It  is  variously  named  in  the  different  parts  of  its 
course  ;  hence  it  is  divided  into  the 

Mouth, 
Pharynx, 
(Esophagus, 
Stomach, 

C  Duodenum, 
Small  intestine      <  Jejunum, 

f  Ileum. 


502  MOUTH HARD    PALATE. 

C  Caecum, 

Large  intestine      <  Colon, 
(  Rectum. 

The  Mouth  is  the  irregular  cavity  which  contains  the  organs  of  taste  and 
the  principal  instruments  of  mastication.  It  is  bounded  in  front  by  the 
lips ;  on  either  side  by  the  internal  surface  of  the  cheeks ;  above  by  the 
hard  palate  and  teeth  of  the  upper  jaw ;  below  by  the  tongue,  by  the  mu- 
cous membrane  stretched  between  the  arch  of  the  lower  jaw  and  the  under 
surface  of  the  tongue,  and  by  the  teeth  of  the  inferior  maxilla ;  and  behind 
by  the  soft  palate  and  fauces. 

The  Lips  are  two  fleshy  folds  formed  externally  by  common  integument, 
and  internally  by  mucous  membrane,  and  containing  between  these  two 
layers  the  muscles  of  the  lips,  a  quantity  of  fat,  and  numerous  small  labial 
glands.  They  are  attached  to  the  surface  of  the  upper  and  lower  jaw,  and 
each  lip  is  connected  to  the  gum  in  the  middle  line  by  a  fold  of  mucous 
membrane,  the  fraenum  labii  superioris  and  frsenum  labii  inferioris,  the 
former  being  the  larger. 

The  Cheeks  (buccse)  are  continuous  on  either  hand  with  the  lips,  and 
form  the  sides  of  the  face ;  they  are  composed  of  integument,  a  large 
quantity  of  fat,  muscles,  mucous  membrane,  and  buccal  glands. 

The  mucous  membrane  lining  the  cheeks  is  reflected  above  and  below 
upon  the  sides  of  the  jaws,  and  is  attached  posteriorly  to  the  anterior 
margin  of  the  ramus  of  the  lower  jaw.  At  about  its  middle,  opposite  the 
second  molar  tooth  of  the  upper  jaw,  is  a  papilla,  upon  which  may  be 
observed  a  small  opening,  the  aperture  of  the  duct  of  the  parotid  gland. 

The  Hard  palate  is  a  dense  structure,  composed  of  mucous  membrane, 
palatal  glands,  fibrous  tissue,  vessels,  and  nerves,  and  firmly  connected  to 
the  palate  processes  of  the  superior  maxillary  and  palate  bones.  It  is 
bounded  in  front  and  on  each  side  by  the  alveolar  processes  and  gums, 
and  is  continuous  behind  with  the  soft  palate.  Along  the  middle  line  it 
is  marked  by  an  elevated  raphe,  and  presents  upon  each  side  of  the  raphe 
a  number  of  transverse  ridges  and  grooves.  Near  its  anterior  extremity, 
and  immediately  behind  the  middle  incisor  teeth,  is  a  papilla  which  cor- 
responds with  the  termination  of  the  naso-palatine  canal,  and  has  been 
supposed  to  be  endowed  with  a  peculiar  sensibility. 

The  Gums  are  composed  of  a  thick  and  dense  mucous  membrane, 
which  is  closely  adherent  to  the  periosteum  of  the  alveolar  processes,  and 
embraces  the  necks  of  the  teeth.  They  are  remarkable  for  their  hardness 
and  insensibility ;  and  for  their  close  contact,  without  adhesion,  to  the 
surface  of  the  tooth.  From  the  neck  of  the  tooth  they  are  reflected  into 
the  alveolus,  and  become  continuous  with  the  periosteal  (peridental)  mem- 
brane of  that  cavity. 

The  Tongue  has  been  already  described  as  an  organ  of  sense ;  it  is  in- 
vested by  mucous  membrane,  which  is  reflected  from  its  under  part  upon 
the  inner  surface  of  the  lower  jaw,  and  constitutes  with  the  muscles  be- 
neath, the  floor  of  the  mouth.  Upon  the  under  surface  of  the  tongue, 
near  its  anterior  part,  the  mucous  membrane  forms  a  considerable  fold, 
which  is  called  the  fraenum  linguae ;  and  on  each  side  of  the  frsenum  is  a 
large  papilla,  the  commencement  of  the  duct  of  the  submaxillary  gland, 
and  several  smaller  openings,  the  apertures  of  the  ducts  of  the  sublingual 
gland. 


SALIVARY    GLANDS.  503 

The  Soft  palate  (velum  pendulum  palati)  is  a  fold  of  mucous  membrane 
situated  at  the  posterior  part  of  the  mouth.  It  is  continuous,  superiorly, 
with  the  hard  palate,  and  is  composed  of  mucous  membrane,  palatal 
glands,  and  muscles.  Hanging  from  the  middle  of  its  inferior  border  is  a 
small  rounded  process,  the  uvula  ;  and  passing  outwards  from  the  uvula 
on  each  side  are  two  curved  folds  of  the  mucous  membrane,  the  arches, 
or  pillars  of  the  palate.  The  anterior  pillar  is  continued  downwards  to 
the  side  of  the  base  of  the  tongue,  and  is  formed  by  the  prominence  of  the 
palato-glossus  muscle.  The  posterior  pillar  is  prolonged  downwards  and 
backwards  into  the  pharynx,  and  is  formed  by  the  convexity  of  the  palato- 
pharyngeus  muscle.  These  two  pillars,  closely  united  above,  are  sepa- 
rated below  by  a  triangular  interval  or  niche,  in  which  the  tonsil  is  lodged. 

The  Tonsils  (amygdala?)  are  two  glandular  organs,  shaped  like  almonds, 
and  situated  between  the  anterior  and  posterior  pillar  of  the  soft  palate,  on 
each  side  of  the  fauces.  They  are  composed  of  an  assemblage  of  mu- 
cous follicles,  which  open  upon  the  surface  of  the  gland.  Externally, 
they  are  invested  by  the  pharyngeal  fascia,  which  separates  them  from  the 
superior  constrictor  muscle  and  internal  carotid  artery,  and  prevents  an 
abscess  from  opening  in  that  direction.  In  relation  to  surrounding  parts, 
they  correspond  with  the  angle  of  the  lower  jaw. 

The  space  included  between  the  soft  palate  and  the  root  of  the  tongue 
is  the  isthmus  of  the  fauces.  It  is  bounded  above  by  the  soft  palate  ;  on 
each  side  by  the  pillars  of  the  soft  palate  and  tonsils  ;  and  below  by  the 
root  of  the  tongue.  It  is  the  opening  between  the  mouth  and  pharynx. 

SALIVARY    GLANDS. 

Communicating  with  the  mouth  are  the  excretory  ducts  of  three  pairs 
of  salivary  glands,  the  parotid,  submaxillary,  and  sublingual. 

The  Parotid  gland,  (ffo^a,  near,  o5&,  wro?,  the  ear,)  the  largest  of  the 
three,  is  situated  immediately  in  front  of  the  external  ear,  and  extends 
superficially  for  a  short  distance  over  the  masseter  muscle,  and  deeply  be- 
hind the  ramus  of  the  lower  jaw.  It  reaches  inferiorly  to  below  the  level 
of  the  angle  of  the  lower  jaw,  and  posteriorly  to  the  mastoid  process, 
slightly  overlapping  the  insertion  of  the  sterno-mastoid  muscle.  Embedded 
in  its  substance  are  the  external  carotid  artery,  temporo-maxillary  vein, 
and  facial  nerve  ;  emerging  from  its  anterior  border,  the  transverse  facial 
artery  and  branches  of  the  pes  anserinus;  and  above,  the  temporal  artery. 

The  duct  of  the  parotid  gland  (Stenon's*  duct)  commences  at  the  pa- 
pilla upon  the  internal  surface  of  the  cheek,  opposite  the  second  molar 
tooth  of  the  upper  jaw  ;  and,  piercing  the  buccinator  muscle,  crosses  the 
masseter  to  the  anterior  border  of  the  gland,  where  it  divides  into  several 
branches,  which  subdivide  and  ramify  through  its  structure,  to  terminate 
in  the  small  caecal  pouches  of  which  the  gland  is  composed.  A  small 
branch  is  generally  given  off'  from  the  duct  while  crossing  the  masseter 
muscle,  which  forms,  by  its  ramifications  and  terminal  dilatations,  a  small 
glandular  appendage,  the  soda  parotidis.  Stenon's  duct  is  remarkably 
dense  and  of  considerable  thickness,  while  the  area  of  its  canal  is  extremely 
small. 

The  Submaxillary  gland  is  situated  in  the  posterior  angle  of  the  sub- 

*  Nicholas  Stenon,  an  anatomist  of  great  research.  He  discovered  the  parotid  juci 
while  in  Paris.  He  was  appointed  Professor  of  Medicine  in  Copenhagen  in  161U  Hit 
work,  "De  Musculis  et  Glandulis  Observationes,"  was  published  in  1664 


504  PHARYNX. 

maxillary  triangle  of  the  neck.  It  rests  upon  the  hyo-glossus  and  mylo- 
hyoideus  muscles,  and  is  covered  in  by  the  body  of  the  lower  jaw  and  by 
the  deep  cervical  fascia.  It  is  separated  from  the  parotid  gland  by  the 
stylo-maxillary  ligament,  and  from  the  sublingual  by  the  mylo-hyoideus 
muscle.  Embedded  among  its  lobules  are  the  facial  artery  and  submax- 
illary  ganglion. 

The  excretory  duct  (Wharton's)  of  the  submaxillary  gland  commences 
upon  the  papilla,  by  the  side  of  the  fraenum  linguae,  and  passes  backwards 
beneath  the  mylo-hyoideus  and  resting  upon  the  hyo-glossus  muscle,  to 
the  middle  of  the  gland,  where  it  divides  into  numerous  branches,  which 
ramify  through  the  structure  of  the  gland,  and  terminate  by  caecal  extremi- 
ties. It  lies  in  its  course  against  the  mucous  membrane  forming  the  floor 
of  the  mouth,  and  causes  a  prominence  of  that  membrane. 

The  Sublingual  is  an  elongated  and  flattened  gland,  situated  beneath 
the  mucous  membrane  of  the  floor  of  the  mouth,  on  each  side  of  the  frae- 
num  linguae.  It  is  in  relation,  above,  with  the  mucous  membrane ;  in 
front,  with  the  depression  by  the  side  of  the  symphysis  of  the  lower  jaw ; 
externally,  with  the  mylo-hyoideus  muscle  ;  and,  internally,  with  the  hy- 
poglossal  nerve  and  genio-hyo-glossus  muscle. 

It  pours  its  secretion  into  the  mouth  by  seven  or  eight  small  ducts, 
which  open  by  small  apertures  on  each  side  of  the  franum  lingua;. 

Structure. — The  salivary  are  conglomerate  glands,  consisting  of  lobes, 
which  are  made  up  of  polyhedral  lobules,  and  these  of  smaller  lobules. 

The  smallest  lobule  is  apparently  composed  of  granules,  which  are  mi- 
nute CEecal  pouches,  formed  by  the  dilatation  of  the  extreme  ramifications 
of  the  ducts.  These  minute  ducts  unite  to  form  lobular  ducts,  and  the 
lobular  ducts  constitute  by  their  union  a  single  excretory  duct.  The  csecal 
pouches  are  connected  by  areolo-fibrous  tissue,  so  as  to  form  a  minute 
lobule  ;  the  lobules  are  held  together  by  a  more  condensed  areolar  layer ; 
and  the  larger  lobes  are  enveloped  by  a  dense  areolo-fibrous  capsule, 
which  is  firmly  attached  to  the  deep  cervical  fascia. 

Vessels  and  Nerves. — The  parotid  gland  is  abundantly  supplied  with 
arteries  by  the  external  carotid  ;  the  submaxillary  by  the  facial ;  and  the 
sublingual  by  the  sublingual  branch  of  the  lingual  artery. 

The  Nerves  of  the  parotid  gland  are  derived  from  the  auricular  branch 
of  the  inferior  maxillary,  from  the  auricularis  magnus,  and  from  the  nervi 
molles  accompanying  the  external  carotid  artery.  The  submaxillary  gland 
is  supplied  by  the  branches  of  the  submaxillary  ganglion,  and  by  filaments 
from  the  mylo-hyoidean  nerve ;  and  the  sublingual  by  filaments  from  the 
submaxillary  ganglion  and  gustatory  nerve. 

PHARYNX. 

Ine  pharynx  (<p«fuyf,  the  throat)  is  a  musculo-membranous  sac,  situated 
upon  the  cervical  portion  of  the  vertebral  column,  and  extending  from  the 
base  of  the  skull  to  a  point  corresponding  with  the  cricoid  cartilage  in 
front,  and  the  fifth  cervical  vertebra  behind.     It  is  composed  of  mucous 
membrane,  muscles,  vessels,  and  nerves,  and  is  invested  by  a  strong  fascia, 
situated  between  the  mucous  membrane  and  muscles,  which  serves  to 
connect  it  with  the  basilar  process  of  the  occipital  bone  and  with  the  pe 
trous  portions  of  the  temporal  bones.     Upon  its  anterior  part  it  is  incom 
plete,  and  has  opening  into  it  seven  foramina,  viz. — 


Fig.  220* 


THE    STOMACH.  505 

Posterior  nares,  two, 

Eustachian  tubes,  two, 

Mouth, 

Larynx, 

(Esophagus. 

The  Posterior  nares  are  the  two  large  openings  at  the  upper  and  front 
part  of  the  pharynx.  On  each  side  of  these  openings,  and  slightly  above 
the  posterior  termination  of  the  inferior  turbinated  bone,  is  the  irregular 
depression  in  the  mucous  membrane,  marking  the  entrance  of  the  Eusta- 
chian tube.  Beneath  the  posterior  nares  is  the  large  opening  into  the 
mouth,  partly  veiled  by  the  soft  palate ;  and,  beneath  the  root  of  the  tongue, 
the  cordiform  opening  of  the  larynx.  The  cesophageal  opening  is  the  lower 
constricted  portion  of  the  pharynx. 

(Esophagus. — The  esophagus  (o"sw,  to  bear, 
(pa^Eiv,  to  eat)  is  a  slightly  flexuous  canal,  in- 
clining to  the  left  in  the  neck,  to  the  right  in  the 
upper  part  of  the  thorax,  f  and  again  to  the  left 
in  its  course  through  the  posterior  mediastinum ; 
it  commences  at  the  termination  of  the  pharynx, 
opposite  the  lower  border  of  the  cricoid  cartilage 
and  fifth  cervical  vertebra,  and  descends  the 
neck  behind  and  rather  to  the  left  of  the  trachea. 
It  then  passes  behind  the  arch  of  the  aorta,  and 
along  the  posterior  mediastinum,  lying  in  front 
of  the  thoracic  aorta,  to  the  resophageal  opening 
in  the  diaphragm,  where  it  enters  the  abdomen, 
and  terminates  at  the  cardiac  orifice  of  the  sto- 
mach at  a  point  about  opposite  the  tenth  dorsal 
vertebra.  The  resophagus  is  flattened  and  nar- 
row in  the  cervical  region,  and  cylindrical  in  the 
rest  of  its  course ;  its  largest  diameter  is  met 
with  near  the  lower  part  of  its  course. 

THE  STO'MACH. 

The  stomach  is  an  expansion  of  the  alimentary  canal,  situated  in  the 
left  hypochondriac,  and  extending  into  the  epigastric  region.  It  is  di- 
rected somewhat  obliquely  from  above  downwards,  from  left  to  right,  and 
from  before  backwards  ;  and  in  the  female,  where  the  injurious  system  of 
tight-lacing  has  been  pursued,  is  longer  than  in  the  male.  On  account 
of  the  peculiarity  of  its  form,  it  is  divided  into  a  greater  or  splenic,  and  a 
lesser  or  pyloric,  end ;  a  lesser  curvature  above,  and  a  greater  curvature 
below ;  an  anterior  and  a  posterior  surface ;  a  cardiac  onjice,  and  a  pyloric 
orifice.  The  great  end  is  not  only  of  large  size,  but  expands  beyond  the 

*  The  pharynx  laid  open  From  behind.  1.  A  section  carried  transversely  through  the 
base  of  the  skull.  2,  2.  The  walls  of  the  pharynx  drawn  to  each  side.  3,  3.  The  pos- 
terior nares,  separated  by  the  vomer.  4.  The  extremity  of  the  Eustachian  tube  of  one 
side.  5.  The  soft  palate.  6.  The  posterior  pillar  of  the  soft  palate.  7.  Its  anterior 
pilJar;  the  tonsil  is  seen  in  the  niche  between  the  two  pillars.  8.  The  root  of  the 
tongue,  partly  concealed  by  the  uvula.  9.  The  epiglottis,  overhanging  (10)  the  cordi- 
form opening  of  the  larynx.  11.  The  posterior  part  of  the  larynx.  12.  The  opening 
into  the  oesophagus.  13.  The  external  surface  of  the  oesophagus.  14.  The  trachea. 

j-  Cruveilhier  remarks  that  this  inflexion  explains  the  obstruction  which  a  Lougi* 
•ometimes  meets  with,  in  its  passage  along  the  oesophagus,  opposite  the  first  rib. 

43 


506  SMALL    INTESTINES. 

point  of  entrance  of  the  oesophagus,  and  is  embraced  by  the  concave  sur 
face  of  the  spleen.  The  pylorus  is  the  small  and  contracted  extremity  of 
the  organ ;  near  its  extremity  is  a  small  dilatation  which  was  called  by 
Willis  the  antrum  of  the  pylorus.  The  two  curvatures  give  attachment  to 
the  peritoneum ;  the  upper  curve  to  the  lesser  omentum,  and  the  lower  to 
the  greater  omentum.  The  anterior  surface  looks  upwards  arid  forwards, 
and  is  in  relation  with  the  diaphragm,  (which  separates  it  from  the  viscera 
of  the  thorax  and  from  the  six  lower  ribs,)  with  the  left  lobe  of  the  liver, 
and  in  the  epigastric  region  with  the  abdominal  parietes.  The  posterior 
surface  looks  downwards  and  backwards,  and  is  in  relation  with  the  dia- 
phragm, the  pancreas,  the  third  portion  of  the  duodenum,  the  transverse 
meso-colon,  the  left  kidney,  and  left  supra-renal  capsule;  this  surface 
forms  the  anterior  boundary  of  that  cul-de-sac  of  the  peritoneum  which  is 
situated  behind  the  lesser  omentum  and  extends  into  the  greater  omentum. 


SMALL    INTESTINE 


The  small  intestine  is  about  twenty-five  feet  in  length,  and  is  divisible 
into  three  portions,  duodenum,  jejunum,  and  ileum. 

The  Duodenum  (called  <5w<5sxo«$axTuXov  by  Herophilus)  is  somewhat  larger 
than  the  rest  of  the  small  intestines,  and  has  received  its  name  from  being 

Fig.  221.* 


about  equal  in  length  to  the  breadth  of  twelve  fingers.  Commencing  at 
the  pylorus,  it  ascends  obliquely  backwards  to  the  under  surface  of  the 
liver ;  it  next  descends  perpendicularly  in  front  of  the  right  kidney,  and 

*  A  vertical  and  longitudinal  section  of  the  stomach  and  duodenum,  made  in  such  a 
direction  as  to  include  the  two  orifices  of  the  stomach.  1.  The  oesophagus;  tpon  its 
internal  surface  the  plicated  arrangement  of  the  cuticular  epithelium  is  shown.  2.  The 
cardiac  orifice  of  the  stomach,  around  which  the  fringed  border  of  the  cuticular  epithe- 
lium is  seen.  3.  The  great  end  of  the  stomach.  4.  Its  lesser  or  pyloric  end.  5.  The 
lesser  curve.  6.  The  greater  curve.  7.  The  dilatation  at  the  lesser  end  of  the  stomach, 
which  has  received  from  Willis  the  name  of  antrum  of  the  pylorus.  This  may  be  re- 
garded as  the  rudiment  of  a  second  stomach.  8.  The  rugas  of  the  stomach,  formed  by 
•he  MUCOUS  membrane  :  their  longitudinal  direction  is  shown.  9.  The  pylorus.  10. 
The  oblique  portion  of  the  duodenum.  11.  The  descending  portion.  12.  The  pancreatic 
duct  and  the  ductus  communis  choledochus  close  to  their  termination.  13.  The  papilla 
upon  which  the  ducts  open.  14.  The  transverse  portion  of  the  duodenum.  15.  The 
commencement  of  the  jejunum.  In  the  interior  of  the  duodenum  and  jejunum  the  val- 
vulae  conniventes  are  seen 


LARGE    INTESTINE.  507 

then  passes  nearly  transversely  across  the  third  lumbar  vertebra  ;  terminat- 
ing in  the  jejunum  on  the  left  side  of  the  second  lumbar  vertebra,  where 
it  is  crossed  by  the  superior  mesenteric  artery  and  vein.  The  first  or 
oblique  portion  of  its  course,  between  two  and  three  inches  in  length,  is 
completely  enclosed  by  the  peritoneum :  it  is  in  relation,  above  with  the 
liver  and  neck  of  the  gall-bladder ;  in  front  with  the  great  omentum  and 
abdominal  parietes ;  and  behind  with  the  right  border  of  the  lesser  omen- 
tum and  its  vessels.  The  second  or  perpendicular  portion  is  situated  alto- 
gether behind  the  peritoneum ;  it  is  in  relation  by  its  anterior  surface  with 
the  commencement  of  the  arch  of  the  colon ;  by  its  posterior  surface  with 
the  concave  margin  of  the  right  kidney,  the  inferior  vena  cava,  and  the 
duct  us  communis  choledochus ;  by  its  right  border  with  the  ascending 
colon  ;  and  by  its  left  border  with  the  pancreas.  The  ductus  communis 
choledochus  and  pancreatic  duct  open  into  the  internal  and  posterior  side 
of  the  perpendicular  portion,  a  little  below  its  middle.  The  third  or 
transverse  portion  of  the  duodenum  lies  between  the  diverging  layers  of 
the  transverse  meso-colon,  with  which  and  with  the  stomach  it  is  in  rela- 
tion in  front ;  above,  it  is  in  contact  with  the  lower  border  of  the  pancreas, 
the  superior  mesenteric  artery  and  vein  being  interposed ;  and,  behind,  it 
rests  upon  the  inferior  vena  cava  and  aorta. 

The  Jejunum  (jejunus,  empty)  is  named  from  being  generally  found 
empty.  It  forms  the  upper  two-fifths  of  the  small  intestine  ;  commencing 
at  the  duodenum,  on  the  left  side  of  the  second  lumbar  vertebra,  and  ter- 
minating in  the  ileum.  It  is  thicker  to  the  touch  than  the  rest  of  the 
intestine,  and  has  a  pinkish  tinge  from  containing  more  mucous  membrane 
than  the  ileum. 

The  Ileum  (s1\siv,  to  twist,  to  convolute)  includes  the  remaining  three- 
fifths  of  the  small  intestine.  It  is  somewhat  smaller  in  calibre,  thinner  in 
texture,  and  paler  than  the  jejunum ;  but  there  is  no  mark  by  which  to 
distinguish  the  termination  of  the  one  or  the  commencement  of  the  other. 
It  terminates  in  the  right  iliac  fossa,  by  opening  at  an  obtuse  angle  into 
the  colon. 

The  jejunum  and  ileum  are  surrounded,  above  and  at  the  sides,  by  the 
colon ;  in  front,  they  are  in  relation  with  the  omentum  and  abdominal 
parietes ;  they  are  retained  in  their  position  by  the  mesentery,  which  con- 
nects them  with  the  posterior  wall  of  the  abdomen ;  and  below  they 
descend  into  the  cavity  of  the  pelvis.  At  about  the  lower  third  of  the 
ileum  a  pouch-like  process  or  diverticulum  of  the  intestine  is  occasionally 
seen.  This  is  a  vestige  of  embryonic  structure,  and  is  formed  by  the 
obliteration  of  the  vitelline  duct  at  a  short  distance  from  the  cylinder  of 
the  intestine. 

LARGE     INTESTINE. 

The  large  intestine,  about  five  feet  in  length,  is  sacculated  in  appear- 
ance, and  is  divided  into  the  cacum,  colon,  and  rectum. 

The  Ccecum  (ccecus,  blind)  is  the  blind  pouch,  or  cul-de-sac,  at  the 
commencement  of  the  large  intestine.  It  is  situated  in  the  right  iliac  fossa, 
and  is  retained  in  its  place  by  the  peritoneum  which  passes  over  its  ante- 
rior surface  ;  its  posterior  surface  is  connected  by  loose  areolar  tissue  with 
the  iliac  fascia.  Attached  to  its  extremity  is  the  appendix  vermiformis,  a 
long  worm-shaped  tube,  the  rudiment  of  the  lengthened  caecum  found  in 
all  mammiferous  animals  except  man  and  the  higher  quadrurcana.  Thr 


508  COLON RECTUM. 

Fig.  222.*  appendix  varies  in  length  from  one  to  five  or  six 

inches ;  it  is  about  equal  in  diameter  to  a  goose- 
quill,  and  is  connected  with  the  posterior  and 
left  aspect  of  the  caecum  near  the  extremity  of 
the  ileum.  It  is  usually  more  or  less  coiled  upon 
itself,  and  retained  in  that  coil  by  a  falciform 
duplicature  of  peritoneum.  Its  canal  is  extremely 
small,  and  the  orifice  by  which  it  opens  into  the 
caecum  not  unfrequently  provided  with  an  in- 
complete valve.  Occasionally  the  peritoneum  in- 
vests the  caecum  so  completely  as  to  constitute  a 
meso-caecum,  which  permits  of  an  unusual  degree 
of  movement  in  this  portion  of  the  intestine,  and 
serves  to  explain  the  occurrence  of  hernia  of  the 
CEecum  upon  the  right  side.  The  caecum  is  the 
most  dilated  portion  of  the  large  intestine. 

The  Colon  is  divided  into  ascending,  trans- 
verse, and  descending.  The  ascending  colon  passes 

upwards  from  the  right  iliac  fossa,  through  the  right  lumbar  region,  to 
the  under  surface  of  the  liver.  It  then  bends  inwards  and  crosses  the 
upper  part  of  the  umbilical  region  under  the  name  of  transverse  colon , 
and,  on  the  left  side,  descends  (descending  colon)  through  the  left  lumbar 
region  to  the  left  iliac  fossa,  where  it  makes  a  remarkable  curve  upon 
itself,  which  is  called  the  sigmoid  flexure. 

The  ascending  colon,  the  most  dilated  portion  of  the  large  intestine,  next 
to  the  caecum,  is  retained  in  its  position  in  the  abdomen  either  by  the 
peritoneum  passing  simply  in  front  of  it  or  by  a  narrow  meso-colon.  It  is 
in  relation  in  front  with  the  small  intestine  and  abdominal  parietes  ;  behind 
with  the  quadratus  lumborum  muscle  and  right  kidney  ;  internally  with  the 
small  intestine  and  the  perpendicular  portion  of  the  duodenum  ;  and  by  its 
upper  extremity  with  the  under  surface  of  the  liver  and  gall-bladder.  The 
transverse  colon,  the  longest  portion  of  the  large  intestine,  forms  a  curve 
across  the  cavity  of  the  abdomen,  the  convexity  of  which  looks  forwards 
and  sometimes  downwards.  It  is  in  relation,  by  its  upper  surface,  with  the 
liver,  gall-bladder,  stomach,  and  lo\ver  extremity  of  the  spleen ;  by  its 
lower  surface,  with  the  small  intestine ;  by  its  anterior  surface,  with  the 
anterior  layers  of  the  great  omentum  and  the  abdominal  parietes ;  and,  by 
its  posterior  surface,  with  the  transverse  meso-colon.  The  descending  colon 
is  smaller  in  calibre,  and  is  situated  more  deeply  than  the  ascending  colon. 
Its  relations  are  precisely  similar.  The  sigmoid  flexure  is  the  narrowest 
part  of  the  colon  ;  it  curves  in  the  first  place  upwards  and  then  downwards, 
and  to  one  or  the  other  side,  and  is  retained  in  its  place  by  a  meso-colon. 
It  is  in  relation,  in  front,  with  the  small  intestine  and  abdominal  parietes; 
behind,  with  the  iliac  fossa,  and,  on  either  side,  with  the  small  intestine. 

The  Rectum  is  the  termination  of  the  large  intestine.  It  has  received 
its  name,  not  so  much  fr<5m  the  direction  of  its  course,  as  from  the  straight- 
ness  of  its  form  in  comparison  with  the  colon.  It  descends,  from  opposite 

*  The  cascum,  showing  its  appendix,  the  entrance  of  the  ileum,  and  the  ileo-crecal 
valve.  I.  The  caecum.  2.  The  commencement  of  the  colon.  3.  The  ileum.  4.  The 
aperture  of  entrance  of  the  ileum  into  the  caecum.  5.  5.  The  ileo-csecal  valve.  6.  The 
aperture  of  the  appendix  vermiformis  cseci.  7.  The  appendix  vermifor'mis.  8,  8.  Sac- 
cull  of  the  colon,  separated  by  valvular  septa.  9.  The  falciform  fraenum  of  the  appendix 
vermiformis. 


STRUCTURE    OF   THE    INTESTINAL    CANAL.  509 

ihe  left  sacro-iliac  symphysis,  in  front  of  the  sacrum,  forming  a  gentle  curve 
to  the  right  side,  and  then  returning  to  the  middle  line  ;  near  the  extremity 
of  the  coccyx  it  curves  backwards  to  terminate  at  the  anus  at  about  an  inch 
in  front  of  the  apex  of  that  bone.  The  rectum,  therefore,  forms  a  double 
flexure  in  its  course,  the  one  being  directed  from  side  to  side,  the  other 
from  before  backwards.  It  is  smaller  in  calibre  at  its  upper  part  than  the 
sigmoid  flexure,  but  becomes  gradually  larger  as  it  descends,  and  its 
lower  extremity,  previously  to  its  termination  at  the  anus,  forms  a  dilata- 
tion of  considerable  but  variable  magnitude. 

With  reference  to  its  relations,  the  rectum  is  divided  into  three  por- 
tions ;  the  first,  including  half  its  length,  extends  to  about  the  middle 
of  the  sacrum,  is  completely  surrounded  by  peritoneum,  and  connected 
to  the  sacrum  by  means  of  the  meso-rectum.  It  is  in  relation,  above,  with 
the  left  sacro-iliac  symphysis ;  and,  below,  with  the  branches  of  the  inter- 
nal iliac  artery,  and  with  the  sacral  plexus  of  nerves ;  one  or  two  convo- 
lutions of  the  small  intestine  are  interposed  between  the  front  of  the  rectum 
and  the  bladder,  in  the  male ;  and  between  the  rectum  and  the  uterus  with 
its  appendages,  in  the  female.  The  second  portion,  about  three  inches  in 
length,  is  closely  attached  to  the  surface  of  the  sacrum,  and  covered  by 
peritoneum  only  in  front ;  it  is  in  relation  by  its  lower  part  with  the  base 
of  the  bladder,  vesiculee  seminales,  and  prostate  gland,  and  in  the  female 
with  the  vagina.  The  third  portion  curves  backwards  from  opposite  the 
prostate  gland  to  terminate  at  the  anus ;  it  is  embraced  by  the  levatores 
ani,  and  is  about  one  inch  and  a  half  in  length.  It  is  separated  from  the 
membranous  portion  of  the  urethra  by  a  triangular  space ;  in  the  female 
this  space  intervenes  between  the  vagina  and  the  rectum,  and  constitutes 
by  its  base  the  perineum. 

The  Jlnus  is  situated  at  a  little  more  than  an  inch  in  front  of  the  ex- 
tremity of  the  coccyx.  The  integument  around  it  is  covered  with  hairs, 
and  is  thrown  into  numerous  radiated  plaits  which  are  obliterated  during 
the  passage  of  faeces.  The  margin  of  the  anus  is  provided  with  an  abun- 
dance of  sebiparous  glands,  and  the  epiderma  may  be  seen  terminating  by 
a  fringed  and  scalloped  border,  at  a  few  lines  above  the  extremity  of  the 
opening. 

STRUCTURE  OF  THE  INTESTINAL  CANAL. 

The  pharynx  has  three  coats ;  a  mucous  coat,  a  fibrous  coat  derived 
from  the  pharyngeal  fascia,  and  a  muscular  layer.  The  oesophagus  has 
but  two  coats,  the  mucous  and  muscular.  The  stomach  and  intestines 
have  three,  mucous  and  muscular,  and  an  external  serous  investment,  de- 
rived from  the  peritoneum. 

Mucous  COAT. — The  mucous  membrane  of  the  mouth  invests  the  whole 
internal  surface  of  that  cavity,  and  is  reflected  along  the  parotid,  submax- 
illary,  and  sublingual  ducts,  into  the  corresponding  glands.  It  terminates 
anteriorly  upon  the  outer  margin  of  the  red  border  of  the  lips,  and  poste- 
riorly is  continuous  with  the  mucous  lining  of  the  pharynx.  The  mucous 
membrane  of  the  pharynx  is  continuous  with  the  mucous  lining  of  the 
Eustachiari  tubes,  the  nares,  the  mouth,  and  the  larynx.  In  the  oesopha- 
gus it  is  thick,  very  loosely  connected  with  the  muscular  coat,  and  disposed 
in  longitudinal  plica.  In  the  stomach  the  mucous  membrane  is  thin  anu 
43  * 


510 


MUCOUS    COAT. 


vascular  at  the  great  extremity,  and  becomes  thicker  and  lighter  in  colour 
towards  the  pyloric  extremity.  It  is  formed  into  plaits  or  ruga,  which 
are  disposed  for  the  most  part  in  a  longitudinal  direction.  The  ruga3  are 
most  numerous  towards  the  lesser  end  of  the  stomach ;  while  around  the 
cardiac  orifice  they  assume  a  radiated  arrangement.  At  the  pylorus  the 
mucous  membrane  forms  a  circular  or  spiral  fold  which  constitutes  a  part 
of  the  apparatus  of  the  pyloric  valve.  In  the  lower  half  of  the  duodenum, 
the  whole  length  of  the  jejunum,  and  the  upper  part  of  the  ileum,  it  forms 
valvular  folds  called  valvulceconniventes,  which  are  several  lines  in  breadth 
in  the  lower  part  of  the  duodenum  and  upper  portion  of  the  jejunum,  and 
diminish  gradually  in  size  towards  each  extremity.  These  folds  do  not 
entirely  surround  the  cylinder  of  the  intestine,  but  extend  for  about  one- 
half  or  three-fourths  of  its  circumference.  In  the  lower  half  of  the  ileum 
the  mucous'lining  is  without  folds;  hence  the  thinness  of  the  coats  of  this 

Fig.  223* 


intestine  as  compared  with  the  jejunum  and  duodenum.  At  the  termina- 
tion of  the  ileum  in  the  caecum,  the  mucous  membrane  forms  two  folds, 
which  are  strengthened  by  the  muscular  coat,  and  project  into  the  caecum. 
These  are  the  ileo-ccecal  valve  (valvula  Bauhini).  In  the  csecum  and  colon 
the  mucous  membrane  is  raised  into  crescentic  folds,  which  correspond 

*  A  vertical  section  of  the  anterior  parietes  of  the  anus,  with  the  whole  canal  dis- 
played so  as  to  show  the  relations  of  the  sacculi  of  the  middle  region,  and  their  relations 
tc  the  surrounding  parts,  their  orifices  being  marked  with  bristles.  1,  1.  Columns  of  the 
rectiun.  2,  2.  Rudiments  of  columns.  3.  Internal  sphincter.  4.  External  sphincter. 
6.  Rudimentary  or  imperfect  sacculi.  5,  5.  Radiated  folds  of  the  skin,  terminating  on 
a'e  surface  of  the  nates.  7.  A  bristle  in  one  of  the  sacs. — G. 


STRUCTURE    OF    MUCOUS    MEMBRANE.  511 

with  the  sharp  edges  of  the  sacculi ;  and,  in  the  rectum,  it  forms  three 
valvular  folds,*  one  of  which  is  situated  near  the  commencement  of  the 
intestine ;  the  second,  extending  from  the  side  of  the  tube,  is  placed  op- 
posite the  middle  of  the  sacrum ;  and  the  third,  which  is  the  largest  and 
most  constant,  projects  from  the  anterior  wall  of  the  intestine  opposite  the 
base  of  the  bladder.  Besides  these  folds,  the  membrane  in  the  empty 
state  of  the  intestine  is  thrown  into  longitudinal  plaits,  somewhat  similar 
to  those  of  the  ossophagus ;  these  have  been  named  the  columns  of  the 
rectum.  The  mucous  membrane  of  the  rectum  is  connected  to  the  mus- 
cular coat  by  a  very  loose  areolar  tissue,  as  in  the  oesophagus,  f 

Structure  of  Mucous  Membrane. — Mucous  membrane  is  analogous  to 
the  cutaneous  covering  of  the  exterior  of  the  body,  and  resembles  that  tis- 
sue very  closely  in  its  structure.  It  is  composed  of  three  layers,  an  epitJie- 
lium,  a.  proper  mucous,  and  a  fibrous  layer. 

The  Epithelium  is  the  epiderma  of  the  mucous  membrane.  Throughout 
the  pharynx  and  oesophagus  it  resembles  the  epiderma,  both  in  appear- 
ance and  character.  It  is  continuous  with  the  epiderma  of  the  skin  at  the 
margin  of  the  lips,  and  terminates  by  an  irregular  border  at  the  cardiac 
orifice  of  the  stomach.  At  the  opposite  extremity  of  the  canal  it  terminates 
by  a  scalloped  border  just  within  the  verge  of  the  anus.  In  the  mouth  it 
is  composed  of  laminae  of  cytoblasts,  cells,  and  polyhedral  scales  (fig.  209). 
Each  cell  and  each  scale  possesses  a  central  nucleus,  and  within  the  nu- 
cleus are  one  or  more  nucleus-corpuscles.  According  to  Mr.  Nasmyth,J 
the  deepest  lamina  of  the  epithelium  appears  to  consist  of  nuclei  (cytoblasts) 
only ;  in  the  next  the  investing  vesicle  or  cell  is  developed ;  the  cells  by 
degrees  enlarge  and  become  flattened,  and  in  the  superficial  laminae  are 
converted  into  thin  scales.  The  nuclei,  the  cells,  and  the  scales  are  con- 
nected together  by  a  glutinous  fluid  of  the  consistence  of  jelly,  which  con- 
tains an  abundance  of  minute  opaque  granules.  The  scales  of  the  super- 
ficial layer  overlap  each  other  by  their  margins.  During  the  natural 
functions  of  the  mucous  membrane  the  superficial  scales  exfoliate  continu- 
ally and  give  place  to  the  deeper  layers.  In  the  stomach  and  intestines  these 
bodies  are  pyriform  in  shape,  and  have  a  columnar  arrangement,  the  apices 
being  applied  to  the  papillary  surface  of  the  membrane,  and  the  bases 
forming,  by  their  approximation,  the  free  intestinal  surface.  Each  column 
is  provided  with  a  central  nucleus  and  nucleus-corpuscle,  which  gives  its 
middle  a  swollen  appearance ;  and,  from  the  transparency  of  its  structure, 
the  nucleus  may  be  seen  through  the  base  of  the  column,  when  examined 
from  the  surface.  Around  the  circular  villi,  the  columns,  from  being 
placed  perpendicularly  to  the  surface,  have  a  radiated  arrangement.  The 
columnar  epithelium  is  produced,  in  the  same  manner  with  the  laminated 
epithelium,  in  cytoblasts,  cells,  and  columns,  and  the  latter  are  continually 
hrown  off  to  give  place  to  successive  layers. 

*  Mr.  Houston,  "  On  the  Mucous  Membrane  of  the  Rectum."  Dublin  Hospital  Re- 
ports, vol.  v. 

•[•The  spaces  between  the  columns  of  the  rectum  become  closed  at  the  anus  so  as  to 
form  a  series  of  pouches  represented  in  the  accompanying  cut.  These  pouches  are 
sometimes  dilated  and  produce  a  disease  first  described  by  Dr.  Physick.  (See  Gibson's 
Surgery.)  The  mucous  membrane  of  the  rectum  is  connected  to  the  muscuiar  coat  by 
a  very  loose  cellular  tissue,  as  in  the  oesophagus. — G. 

$  Investigations  into  the  structure  of  the  Epithelium,  presented  to  the  medical  section 
of  the  British  Medical  Association,  in  1839,  published  in  a  work  enticed  "  Thr^s  .Me 
moirs  on  the  Development  of  the  teeth  and  epithelium,"  1841. 


512  PAPILLARY    LAYER — FIBROUS    LAYER. 

The  Proper  mucous,  or  Papillary  layer  is  analogous  to  the  papillary 
layer  of  the  skin,  and,  like  it,  is  the  formative  structure  by  which  the  epi- 
thelium is  produced.  Its  surface  presents  several  varieties  of  appearance 
when  examined  in  different  parts  of  its  extent.  In  the  stomach  it  forms 
polyhedral  cells,  into  the  floor  of  wh'ch  the  gastric  follicles  open.  In  the 
small  intestine  it  presents  numerous  minute,  projecting  papilla?,  called 
villi.  The  villi  are  of  two  kinds,  cylindrical  and  laminated,  and  so  abun- 
dant, as  to  give  to  the  entire  surface  a  beautiful  velvety  appearance.  In 
the  large  intestine  the  surface  is  composed  of  a  fine  network  of  minute 
polyhedral  cells,  more  numerous  than  those  of  the  stomach,  but  resem- 
bling them  in  receiving  the  secretion  from  numerous  perpendicular  fol- 
licles into  their  floors. 

The  Fibrous  layer  (sub-mucous,  nervous)  is  the  membrane  of  support 
to  the  mucous  membrane,  as  is  the  corium  to  the  papillary  layer  of  the 
skin.  It  gives  to  the  mucous  membrane  its  strength  and  resistance,  is  but 
loosely  connected  with  the  mucous  layer,  but  is  firmly  adherent  to  the 
muscular  stratum,  and  is  called,  in  the  older  works  on  anatomy,  the 
" nervous  coat." 

Glands.  —  In  the  loose  areolar  tissue  connecting  the  mucous  with  the 
fibrous  layer,  are  situated  the  glands  and  follicles  belonging  to  the  mucous 
membrane :  these  are  the — 

Pharyngeal  glands, 

CEsophageal  glands, 

Gastric  follicles, 

Duodenal  glands  (Brunner's), 

GlandulaB  solitaries, 

Gl  an  dulse  aggregate  (Peyer's), 

Simple  follicles  (Lieberkuhn's). 

The  Pharyngeal  glands  are  situated  in  considerable  numbers  beneath 
the  mucous  membrane  of  the  pharynx,  particularly  around  the  posterior 
nares.  Two  of  these  glands,  of  larger  size  than  the  rest,  and  lobulated 
in  structure,  occupy  the  margin  of  the  opening  of  the  Eustachian  tube. 

The  CEsophageal  glands  are  small  lobulated  bodies,  situated  in  the  sub- 
mucous  tissue,  and  opening  upon  the  surface  of  the  oesophagus  by  a  long 
excretory  duct,  which  passes  obliquely  through  the  mucous  membrane. 

The  Gastric  follicles  are  long  tubular  follicular  glands,  situated  perpen- 
dicularly side  by  side  in  every  part  of  the  mucous  membrane  of  the  sto- 
mach. At  their  terminations  they  are  dilated  into  small  lateral  pouches, 
which  give  them  a  clustered  appearance.  This  character  is  more  clearly 
exhibited  at  the  pyloric  than  at  the  cardiac  end  of  the  stomach.  They  are 
intended,  very  probably,  for  the  secretion  of  the  gastric  fluid. 

The  Duodenal,  or  Brunner's*  glands,  are  small  flattened  granular 
bodies,  compared  collectively  by  Von  Brunn  to  a  second  pancreas.  They 
resemble  in  structure  the  small  salivary  glands,  so  abundant  beneath  the 
mucous  membrane  of  the  mouth  and  lips ;  and,  like  them,  they  open 
upon  the  surface  by  minute  excretory  ducts.  They  are  limited  to  the 
duodenum. 

The  Solitary  glands  are  of  two  kinds,  those  of  the  small  and  those  of 
the  large  intestine.  The  former  are  small  circular  patches,  surrounded 

•John  Conrad  von  Brunn:  "Glandulee  Duodeni  seu  Pancreas  Secundarium,"  1715. 


MUSCULAR    COAT. 


513 


Fig.  224.J 


by  a  zone  or  wreath  of  simple  follicles.  When  opened,  they  are  seen  to 
consist  of  a  small  flattened  saccular  cavity,  containing  a  mucous  secretion, 
but  having  no  excretory  duct.  They  are  chiefly  found  in  the  lower  part 
of  the  ileum.  The  solitary  glands  of  the  large  intestine  are  most  abundant 
m  the  caecum  and  appendix  cseci ;  they  are  small  circular  prominences, 
flattened  upon  the  surface,  and  perforated  in  the  centre  by  a  minute  ex- 
cretory opening. 

The  Aggregate,  or  Peyer's*  glands,  are  situated  near  the  lower  end  of 
the  ileum,  and  occupy  that  portion 
of  the  intestine  which  is  opposite  the 
attachment  of  the  mesentery.  To 
the  naked  eye  they  present  the  ap- 
pearance of  oval  disks,  covered  with 
small  irregular  fissures ;  but  with  the 
aid  of  the  microscope  they  are  seen 
to  be  composed  of  numerous  small 
circular  patches,  surrounded  by  sim- 
ple follicles,  like  the  solitary  glands 
of  the  small  intestine.  Each  patch 
corresponds  with  a  flattened  and 
closed  sac,  situated  beneath  the 
membrane,  but  having  no  excretory 
opening,  and  the  interspace  between 
the  patches  is  occupied  by  flattened 
villi. 

The  Simple  follicles,  or  follicles  of  Lieberkiihn,  are  small  pouches  of 
the  mucous  layer,  dispersed  in  immense  numbers  over  every  part  of  the 
mucous  membrane. 

MUSCULAR  COAT. — The  muscular  coat  of  the  pharynx  consists  of  five 
pairs  of  muscles,  which  have  been  already  described.  The  muscular  coat 
of  the  rest  of  the  alimentary  canal  is  composed  of  two  planes  of  fibres,  an 
external  longitudinal,  and  an  internal  circular. 

The  (Esophagus  is  very  muscular ;  its  longitudinal  fibres  are  continuous 
above  with  the  pharynx,  and  are  attached  in  front  to  the  vertical  ridge  on 
the  posterior  surface  of  the  cricoid  cartilage  ;  the  uppermost  circular  fibres 
are  also  attached  to  the  cricoid  cartilage.  Below,  both  sets  of  fibres  are 
continued  upon  the  stomach. 

Besides  the  fibres  possessed  by  the  ossophagus  in  common  with  the  rest 
of  the  alimentary  canal,  two  special  muscles  have  been  described  by  Hyrtl 
under  the  names  of  Broncho-ossophageal  and  Pleuro-oesophageal.  The 
Broncho-cesophageal  muscle  arises  as  a  broad  fasciculus  from  the  posterior 
surface  of  the  left  bronchus,  and  is  lost,  after  a  course  of  two  or  three 
inches  in  length,  among  the  longitudinal  fibres  of  the  left  side  of  the  ce'so- 
phagus.  The  Pleuro-cesophageal  muscle  arises  from  the  left  wall  of  the 
posterior  mediastinum  behind  the  commencement  of  the  descending  aorta, 
and  curves  around  that  vessel  to  mingle  its  fibres  with  the  longitudinal 
fibres  of  the  03sophagus. 

*  John  Conrad  Peyer,  an  anatomist  of  SchafThausen,  in  Switzerland.  His  essay,  '-IV 
Glandulis  Intestinorum,"  was  published  in  1677. 

•j- Portion  of  one  of  the  patches  of  Peyer's  glands  from  the  end  of  the  ileum: 
magnified.  "  The  villi  are  also  shown. — (Bothm.) 


514 


SEROUS    COAT. 


Fig.  225* 


On  the  Stomach  the  longitudinal  fibres  are  most  apparent  along  the 
lesser  curve,  and  the  circular  at  the  smaller  end.  At  the  pylorus  the  latter 
are  aggregated  into  a  thick  circular  ring,  which,  with  the  spiral  fold  of 
mucous  membrane  found  in  this  situation,  constitutes  the  pyloric  valve. 
At  the  great  end  of  the  stomach  a  new  order  of  fibres  is  introduced,  hav- 
ing for  their  object  to  strengthen  and  compress  that  extremity  of  the  organ. 
They  are  directed  more  or  less  horizontally  from  the  great  end  towards 
the  lesser  end,  and  are  generally  lost  upon  the  sides  of  the  stomach  at 
about  its  middle  ;  these  are  the  oblique  fibres. 

The  Small  intestine  is  provided  with  both  layers  of  fibres,  equally  dis- 
tributed over  the  entire  surface.  At  the  termination  of  the  ileum  the  cir- 
cular fibres  are  continued  into  the  two 
folds  of  the  ileo-csecal  valve,  while  the 
longitudinal  fibres  pass  onwards  to  the 
large  intestine.  In  the  large  intestine 
the  longitudinal  fibres  commence  at 
the  appendix  vermiformis  and  are  col- 
lected into  three  bands,  an  anterior, 
broad,  and  two  posterior  and  narrower 
bands.  These  bands  are  nearly  one- 
half  shorter  than  the  intestine,  and 
serve  to  maintain  the  sacculated  struc- 
ture which  is  characteristic  of  the 
cum  and  colon.  In  the  descending 
colon  the  posterior  bands  usually  unite 
and  form  a  single  band.  From  this 
point  the  bands  are  continued  down- 
wards upon  the  sigmoid  flexure  to  the 
rectum,  around  which  they  spread  out 
and  form  a  thick  and  very  muscular 
longitudinal  layer.  The  circular  fibres 
in  the  caecum  and  colon  are  exceed- 
ingly thin ;  in  the  rectum  they  are 

thicker,  and  at  its  lower  extremity  they  are  aggregated  into  the  thick  mus- 
cular ring  which  is  known  as  the  internal  sphincter  ani.  Between  the 
latter  and  the  mucous  membrane  are  several  narrow  fasciculi  of  longitudi- 
nal muscular  fibres,  somewhat  more  than  an  inch  in  length,  which  have 
been  described  by  Homer  of  Philadelphia. 

SEROUS  COAT. — The  pharynx  and  resophagus  have  no  covering  of 
serous  membrane.  The  alimentary  canal  within  the  abdomen  has  a  serous 
layer,  derived  from  the  peritoneum. 

*  A  vertical  section  of  the  parietes  of  die  anus,  passing  through  the  middle  line  of 
one  of  the  columns  of  the  rectum,  and  the  neighbouring  parts.  1.  The  internal  sphincter, 
with  its  arched  fibres  transversely  divided.  2,  2.  The  plane  of  arched  fibres  of  the 
muscular  coat,  similarly  divided.  3.  The  point  of  greatest  contraction  of  the  internal 
sphincter.  4.  The  external  sphincter.  5.  The  point  of  greatest  contraction  of  the  same 
mivscle.  6.  The  plane  of  longitudinal  fibres  of  the  muscular  coat,  longitudinally  divided. 
7.  Some  of  these  fibres  terminating  in  the  internal  sphincter.  8.  Others,  terminating  in 
the  external  sphincter.  9.  The  remaining  longitudinal  fibres,  collected  into  a  semiten- 
ilinous  fasciculus,  passing  over  the  lower  margin  of  the  internal  sphincter,  to  be  reverted 
jpward  within  the  duplicature  of  the  column.  10.  These  reverted,  fibres  again  becom- 
ing muscular,  and  terminating  in  the  mucous  coat.  11.  The  mucous  coat.  12.  A  bristle 
•n  one  i  *  the  sacs. — G. 


THE    LIVER.  515 

The  Stomach  is  completely  surrounded  by  peritoneum,  excepting  along 
the  line  of  junction  of  the  great  and  lesser  omentum.  The  first  or°oblique 
portion  of  the  duodenum  is  also  completely  included  by  the  serous  mem- 
brane, with  the  exception  of  the  points  of  attachment  of  the  omenta.  The 
descending  portion  has  merely  a  partial  covering  on  its  anterior  surface. 
The  transverse  portion  is  also  behind  the  peritoneum,  beino-  situated  be- 
tween the  two  layers  of  the  transverse  meso-colon,  and  has  but  a  partial 
covering.  The  rest  of  the  small  intestine  is  completely  invested  by  it, 
excepting  along  the  concave  border  to  which  the  mesentery  is  attached. 
The  ctecum  is  more  or  less  invested  by  the  peritoneum,  the  more  frequent 
disposition  being  that  in  which  the  intestine  is  surrounded  for  three-fourths 
only  of  its  circumference.  The  ascending  and  the  descending  colon  are 
covered  by  the  serous  membrane  only  in  front.  The  transverse  colon  is 
invested  completely,  with  the  exception  of  the  lines  of  attachment  of  the 
greater  omentum  and  transverse  meso-colon.  And  the  sigmoid  flexure  is 
entirely  surrounded,  with  the  exception  of  the  part  corresponding  with  the 
junction  of  the  left  meso-colon.  The  upper  third  of  the  rectum  is  com* 
pletely  enclosed  by  the  peritoneum ;  the  middle  third  has  an  anterior 
covering  only,  and  the  inferior  third  none  whatsoever. 

Vessels  and  Nerves. — The  Arteries  of  the  alimentary  canal,  as  they 
supply  the  tube  from  above  downwards,  are  the  pterygo-palatine,  ascend- 
ing pharyngeal,  superior  thyroid,  and  inferior  thyroid,  in  the  neck ;  ceso- 
phageal,  in  the  thorax ;  gastric,  hepatic,  splenic,  superior  and  inferior 
mesenteric,  in  the  abdomen ;  and  inferior  mesenteric,  iliac,  and  internal 
pudic,  in  the  pelvis.  The  veins  from  the  abdominal  alimentery  canal 
unite  to  form  the  vena  portse.  The  lymphatics  and  lacteals  open  into  the 
thoracic  duct. 

The  Nerves  of  the  pharynx  and  oesophagus  are  derived  from  the  glosso- 
pharyngeal,  pneumogastric,  and  sympathetic.  The  nerves  of  the  stomach 
are  the  pneumogastric,  and  sympathetic  branches  from  the  solar  plexus ; 
and  those  of  the  intestinal  canal  are  the  superior  and  inferior  mesenteric 
and  hypogastric  plexuses.  The  extremity  of  the  rectum  is  supplied  by 
the  inferior  sacral  nerves  from  the  spinal  cord. 
\ 

THE    LIVER. 

THE  liver  is  a  conglomerate  gland  of  large  size,  appended  to  the  ali- 
mentary canal,  and  performing  the  double  office  of  separating  impurities 
from  the  venous  blood  of  the  chylo-poietic  viscera  previously  to  its  return 
into  the  general  venous  circulation,  and  of  secreting  a  fluid  necessary  to 
chylification,  the  bile.  It  is  the  largest  organ  in  the  body,  weighing  about 
four  pounds,  and  measuring  through  its  longest  diameter  about  twelve 
inches.  It  is  situated  in  the  right  hypochondriac  region,  and  extends 
across  the  epigastrium  into  the  left  hypochondriac,  frequently  reaching,  by 
its  left  extremity,  the  upper  end  of  the  spleen.  It  is  placed  obliquely  in 
the  abdomen  ;  its  convex  surface  looking  upwards  and  forwards,  and  the 
concave  downwards  and  backwards.  The  anterior  border  is  sharp  and 
free,  and  marked  by  a  deep  notch,  and  the  posterior  rounded  and  broad. 
It  is  in  relation,  superiorly  and  posteriorly,  with  the  diaphragm;  and  infe- 
riorly,  with  the  stomach,  ascending  portion  of  the  duodenum,  transverse 
colon,  right  supra-renal  capsule,  and  right  kidney;  and  corresponds,  by 
its  free  border,  with  the  lower  margin  of  the  ribs. 


516  LIGAMENTS    OF   THE    LIVER. 

Ligaments. — The  liver  is  retained  in  its  place  by  five  ligaments  ;  four 
of  which  are  duplicatures  of  the  peritoneum,  and  are  situated  on  the  con- 
vex surface  of  the  organ  ;  the  fifth  is  a  fibrous  cord  which  passes  through 
a  fisstire  in  its  under  surface,  from  the  umbilicus  to  the  inferior  vtna  cava. 
They  are  the — 

Longitudinal,  Coronary, 

Two  lateral,  Round. 

The  Longitudinal  ligament  (broad,  ligamentum  suspensorium  hepatis 
is  an  antero-posterior  fold  of  peritoneum,  extending  from  the  notch  on  th 
anterior  margin  of  the  liver  to  its  posterior  border.  Between  its  two  layers 
in  the  anterior  and  free  margin,  is  the  round  ligament. 

The  Lateral  ligaments  are  formed  by  the  two  layers  of  peritoneum,  which 
pass  from  the  under  surface  of  the  diaphragm  to  the  posterior  border  of  the 
liver ;  they  correspond  *vith  its  lateral  lobes. 


The  Coronary  ligament  is  formed  by  the  separation  of  the  two  layers 
forming  the  lateral  ligaments  near  their  point  of  convergence.  The  poste- 
rior layer  is  continued  unbroken  from  one  lateral  ligament  into  the  other ; 
but  the  anterior  quits  the  posterior  at  each  side,  and  is  continuous  with  the 
corresponding  layer  of  the  longitudinal  ligament.  In  this  way  a  large  oval 
surface  on  the  posterior  border  of  the  liver  is  left  uncovered  by  peritoneum, 
and  is  connected  to  the  diaphragm  by  areolo-fibrous  tissue.  This  space 
is  formed  principally  by  the  right  lateral  ligament,  and  is  pierced  near  its 
left  extremity  by  the  inferior  vena  cava,  previously  to  the  passage  of  that 
vessel  through  the  tendinous  opening  in  the  diaphragm. 

The  Round  ligament  is  a  fibrous  cord  resulting  from  the  obliteration  of 
the  umbilical  vein,  and  situated  between  the  two  layers  of  peritoneum'  in 
the  anterior  border  of  the  longitudinal  ligament.  It  may  be  traced  from 
the  umbilicus,  along  the  longitudinal  fissure  of  the  under  surface  of  the 
liver  to  the  inferior  vena  cava,  to  which  it  is  connected. 

Fissures. — The  under  surface  of  the  liver  is  marked  by  five  fissures, 

•  The  upper  surface  of  the  liver.  1.  The  right  lobe.  2.  The  left  lobe.  3.  The  ante- 
rior or  free  border.  4.  The  posterior  or  rounded  border.  5.  The  broad  ligament.  6. 
The  round  ligament.  7,  7.  The  two  lateral  ligaments.  8.  The  space  left  uncovered  by 
Ihe  peritone/im,  and  surrounded  by  the  coronary  ligament.  9.  The  inferior  vena  cava. 
10.  The  point  of  the  lobus  Spigelii.  3.  The  fundus  of  the  gall-bladder  seen  projecting 
beyond  the  anterior  border  of  the  right  lobe. 


FISSURES    OF    THE    LIVER. 


517 


which  divide  its  surface  into  five  compartments  or  lobes,  two  principal  and 
tnree  minor  lobes ;  they  are  the — 


Fissures. 

Longitudinal  fissure, 
Fissure  of  the  ductus  venosus, 
Transverse  fissure, 
Fissure  for  the  gall-bladder, 
Fissure  for  the  vena  cava. 


Lobes. 
Right  lobe, 
Left  lobe, 
Lobus  quadratus, 
Lobus  Spigelii, 
Lobus  caudatus. 


The  Longitudinal  fissure  is  a  deep  groove  running  from  the  notch  upon 
he  anterior  margin  of  the  liver,  to  the  posterior  border  of  the  organ.  At 
about  one-third  from  its  posterior  extremity  it  is  joined  by  a  short  but  deep 
fissure,  the  transverse,  which  meets  it  transversely  from  the  under  part  of 
the  right  lobe. 

The  longitudinal  fissure  in  front  of  this  junction  lodges  the  fibrous  cord 
of  the  umbilical  vein,  and  is  generally  crossed  by  a  band  of  hepatic  sub- 
stance called  the  pons  hepatis. 

The  Fissure  for  the  ductus  venosus  is  the  shorter  portion  of  the  longitu- 
dinal fissure,  extending  from  the  junctional  termination  of  the  transverse 
fissure  to  the  posterior  border  of  the  liver,  and  containing  a  small  fibrous 
cord,  the  remains  of  the  ductus  venosus.  This  fissure  is  therefore  but  a 
part  of  the  longitudinal  fissure. 

Fig.  227  * 


The  Transverse  fissure  is  the  short  and  deep  fissure,  about  two  inches 
in  length,  through  which  the  hepatic  ducts,  hepatic  artery,  and  portal  vein 
enter  the  liver.  Hence  this  fissure  was  considered  by  the  older  anatomists 
as  the  gate  (porta)  of  the  liver ;  and  the  large  vein  entering  the  organ  at 

*  The  under  surface  of  the  liver.  1.  The  right  lobe.  2.  The  left  lobe.  3.  The  lobus 
quadratus.  4.  The  lobus  Spigelii.  5.  The  lobus  caudatus.  6.  The  longitudinal  fissure  ; 
the  numeral  is  placed  on  the  rounded  cord,  the  remains  of  the  umbilical  vein  7  Ihe 
pons  hepatis.  8.  The  fissure  for  the  ductus  venosus ;  the  obliterated  cord  of  the  ductns 
is  seen  passing  backwards  to  be  attached  to  the  coats  of  the  inferior  vena  cava  (9). 
10.  The  gall-bladder  lodged  in  its  fossa.  11.  The  transverse  fissure,  containing,  from 
before  backwards,  the  hepatic  duct,  hepatic  artery,  and  portal  vein.  13.  1  lie  vena 
cava.  13.  A  depression  corresponding  with  the  curve  of  the  colon.  14  A  double  de- 
pression produced  by  the  right  kidney  and  its  supra-renal  capsule.  15.  The  rough  sur 
face  on  the  posterior  border  of  the  liver  left  uncovered  by  peritoneum  ;  the  cut  edge  of 


t^r  i  i\j  i     uwi  »-»*-;*    v*    n*^    •••«•-•*'•- »•  >      _ 

peritoneum   surrounding  this  surface   forms   part  of  the  coronary  ligament      ic.  The 
notch  on  the  anterior  border,  separating  the  two  lobes.     17.  The  notch  on  the  posterior 
border,  corresponding  with  the  vertebral  column. 
44 


518  LOBES    OF    THE    LIVER. 

this  point,  the  portal  vein.  At  their  entrance  into  the  transverse  fissure  the 
branches  of  the  hepatic  duct  are  the  most  anterior,  next  those  of  the  artery, 
and  most  posteriorly  the  portal  vein. 

The  Fissure  for  the  gall-bladder  is  a  shallow  fossa  extending  forwards, 
parallel  with  the  longitudinal  fissure,  from  the  right  extremity  of  the  trans- 
verse fissure  to  the  free  border  of  the  liver,  where  it  frequently  forms  a 
notch. 

The  Fissure  for  the  vena  cava  is  a  deep  and  short  fissure,  occasionally 
a  circular  tunnel,  which  proceeds  from  a  little  behind  the  right  extremity 
of  the  transverse  fissure  to  the  posterior  border  of  the  liver,  and  lodges  the 
inferior  vena  cava. 

These  five  fissures  taken  collectively  resemble  an  inverted  y,  the  base 
corresponding  with  the  free  margin  of  the  liver,  and  the  apex  with  its  pos- 
terior border.  Viewing  them  in  this  way,  the  two  anterior  branches  re- 
present the  longitudinal  fissure  on  the  left,  and  the  fissure  for  the  gall- 
bladder on  the  right  side ;  the  two  posterior,  the  fissure  for  the  ductus 
venosus  on  the  left,  and  the  fissure  for  the  vena  cava  on  the  right  side  ; 
and  the  connecting  bar,  the  transverse  fissure. 

Lobes. — The  Right  lobe  is  four  or  six  times  larger  than  the  left,  from 
which  it  is  separated,  on  the  concave  surface,  by  the  longitudinal  fissure, 
and,  on  the  convex,  by  the  longitudinal  ligament.  It  is  marked  upon  its 
under  surface  by  the  transverse  fissure,  and  by  the  fissures  for  the  gall- 
bladder and  vena  cava ;  and  presents  three  depressions,  one,  in  front,  for 
the  curve  of  the  ascending  colon,  and  two,  behind,  for  the  right  supra- 
renal capsule  and  kidney. 

The  Left  lobe  is  small  and  flattened,  convex  upon  its  upper  surface,  and 
concave  below,  where  it  lies  in  contact  with  the  anterior  surface  of  the 
stomach.  It  is  sometimes  in  contact  by  its  extremity  with  the  upper  end 
of  the  spleen,  and  is  in  relation,  by  its  posterior  border,  with  the  cardiac 
orifice  of  the  stomach  and  left  pneumogastric  nerve. 

The  Lobus  quadralus  is  a  quadrilateral  lobe  situated  on  the  under  sur- 
face of  the  right  lobe  ;  it  is  bounded,  in  front,  by  the  free  border  of  the 
liver ;  behind,  by  the  transverse  fissure ;  to  the  right,  by  the  gall-bladder ; 
and  to  the  left,  by  the  longitudinal  fissure. 

The  Lobus  Spigelii*  is  a  small  triangular  lobe,  also  situated  on  the  under 
surface  of  the  right  lobe :  it  is  bounded,  in  front,  by  the  transverse  fissure  ; 
and,  on  the  sides,  by  the  fissures  for  the  ductus  venosus  and  vena  cava. 

The  Lobus  caudatus  is  a  small  tail-like  appendage  of  the  lobus  Spigelii, 
from  which  it  runs  outwards  like  a  crest  into  the  right  lobe,  and  serves  to 
separate  the  right  extremity  of  the  transverse  fissure  from  the  commence- 
ment of  the  fissure  for  the  vena  cava.  In  some  persons  this  lobe  is  well 
marked,  in  others  it  is  small  and  ill-defined. 

Reverting  to  the  comparison  of  the  fissures  with  an  inverted  y,  it  will 
be  observed,  that  the  quadrilateral  interval,  in  front  of  the  transverse  bar, 
represents  the  lobus  quadratus ;  the  triangular  space  behind  the  bar,  the 
lobus  Spigelii ;  and  the  apex  of  the  letter,  the  point  of  union  between  the 
inferior  vena  cava  and  the  remains  of  the  ductus  venosus. 

Vessels  and  Nerves. — The  vessels  entering  into  the  structure  of  the  liver 
are  also^/zve  in  number;  they  are  the 

*  Adrian  Spigel,  a  Belgian  physician,  professor  at  Padua  after  Casserius  in  1616.  He 
assigned  considerable  importance  to  this  little  lobe,  but  it  had  been  described  by  Syl 
f'US  full  sixty  years  before  his  time. 


STRUCTURAL    ANATOMY    OF    THE    LIVER. 


5iy 


Hepatic  artery, 
Portal  vein, 
Hepatic  veins, 


Hepatic  ducts, 
Lymphatics. 


The  Hepatic  artery,  portal  vein,  and  hepatic  duct  enter  the  liver  at  the 
transverse  fissure,  and  ramify  through  portal  canals  to  every  part  of  the 
organ ;  so  that  their  general  direction  is  from  below  upwards,  and  from 
the  centre  towards  the  circumference. 

The  Hepatic  veins  commence  at  the  circumference,  and  proceed  from 
before  backwards,  to  open  into  the  vena  cava,  on  the  posterior  border  of 
the  liver.  Hence  the  branches  of  the  two  veins  cross  each  other  in  their 
course. 

The  portal  vein,  hepatic  artery,  and  hepatic  duct  are  moreover  enve- 
loped in  a  loose  areolar  tissue,  the  capsule  of  Glisson,  which  permits  them 
to  contract  upon  themselves  when  emptied  of  their  contents  ;  the  hepatic 
veins,  on  the  contrary,  are  closely  adherent  by  their  parietes  to  the  surface 
of  the  canals  in  which  they  run,  and  are  unable  to  contract.  By  these 
characters  the  anatomist  is  enabled,  in  any  section  of  the  liver,  to  distin- 
guish at  once  the  most  minute  branch  of  the  portal  vein  from  an  hepatic 
vein  :  the  former  will  be  found  more  or  less  collapsed,  and  always  accom- 
panied by  an  artery  and  duct,  and  the  latter  widely  open  and  solitary. 

The  Lymphatics  of  the  liver  are  described  in  the  Chapter  dedicated  to 
those  vessels. 

The  Nerves  of  the  liver  are  derived  from  the  systems  both  of  animal 
and  organic  life  ;  the  former  proceed  from  the  right  phrenic  and  pneumo- 
gastric  nerves,  and  the  latter  from  the  hepatic  plexus. 

Structure  and  Minute  Anatomy  of  the  Liver. 

The  Liver  is  composed  of  lobules,  of  a  connecting  medium  called  Glis- 
son's  capsule,  of  the  ramifications  of  the  portal  vein,  hepatic  duct,  hepatic 
artery,  hepatic  veins,  lymphatics,  and  nerves,  and  is  enclosed  and  retained 
in  its  situation  by  the  peritoneum. 

The  Lobules  are  small  granular  bodies,  of  about  the  size  of  a  millet 
seed,  of  an  irregular  form,  and  presenting  a  number  of  rounded  prouri- 


Fig.  22  8« 


Fig.  229.J 


«  The  lobules  of  the  liver.  The  lobules  as  they  are  seen  upon  the  surface  of  the 
liver,  or  when  divided  transversely.  1.  The  intralobular  vein  in  the  centre  of  each 
lobule.  2.  The  interlobular  fissure.  3.  The  interlobular  space. 

|  A  longitudinal  section  of  two  lobules.  1.  A  superficial  lobule,  terminating  abruptly, 
and  resembling  a  section  at  its  extremity.  2.  A  deep  lobule,  showing  the  foliated  ap 
pearance  of  its  section.  3.  The  interlobular  vein,  with  its  converging  venules;  the  vein 
terminates  in  a  sublobular  vein.  4.  The  external,  or  capsular  surface  of  the  lobule 


520 


STRUCTURAL    ANATOMY    OF    THE    LIVER. 


nences  on  their  surface.  When  divided  longitudinally,  they  have  a  foli- 
ated appearance,  and  transversely,  a  polygonal  outline,  with  sharp  or 
rounded  angles,  according  to  the  smaller  or  greater  quantity  of  Glisson's 
capsule  contained  in  the  liver.  Each  lobule  is  divided  upon  its  exterior 
into  a  base  and  a  capsular  surface.  The  base  corresponds  with  one  ex- 
tremity of  the  lobule,  is  flattened,  and  rests  upon  an  hepatic  vein,  which 
is  thence  named  sublobular.  The  capsular  surface  includes  the  rest  of  the 
periphery  of  the  lobule,  and  has  received  its  designation  from  being  en- 
closed in  an  areolar  capsule  derived  from  the  capsule  of  Glisson.  In  the 
centre  of  each  lobule  is  a  small  vein,  the  intralobular,  which  is  formed  by 
the  convergence  of  six  or  eight  minute  venules  from  the  rounded  promi- 
nences of  the  periphery.  The  intralobular  vein  thus  constituted  takes  its 
course  through  the  centre  of  the  longitudinal  axis  of  the  lobule,  pierces 
the  middle  of  its  base,  and  opens  into  the  sublobular  vein.  The  periphery 
of  the  lobule,  with  the  exception  of  its  base,  which  is  always  closely  at- 
tached to  a  sublobular  vein,  is  connected  by  means  of  its  areolar  capsule 
with  the  capsular  surfaces  of  surrounding  lobules.  The  interval  between 
the  lobules  is  the  interlobular  fissure,  and  the  angular  interstices  formed 
by  the  apposition  of  several  lobules  are  the  interlobular  spaces. 

The  lobules  of  the  centre  of  the  liver  are  angular,  and  somewhat  smaller 
than  those  of  the  surface,  from  the  greater  compression  to  which  they  are 
submitted.  The  superficial  lobules  are  incomplete,  and  give  to  the  sur- 
face of  the  organ  the  appearance  and  all  the  advantages  resulting  from  an 
examination  of  a  transverse  section. 

' '  Each  lobule  is  composed  of  a  plexus  of  biliary  ducts,  of  a  venous  plexus, 
formed  by  branches  of  the  portal  vein,  of  a  branch  (intralobular),  of  an 
hepatic  vein,  and  of  minute  arteries ;  nerves  and  absorbents,  it  is  to  be  pre- 
sumed, also  enter  into  their  formation,  but  cannot  be  traced  into  them." 
"  Examined  with  the  microscope,  a  lobule  is  apparently  composed  of  nume- 
rous minute  bodies  of  a  yellowish  colour  and  of  various  forms,  connected 
with  each  other  by  vessels.  These  minute  bodies  are  the  acini  of  Malpighi." 

"  If  an  uninjected  lobule  be  exa- 
mined and  contrasted  with  an  injected 
lobule,  it  will  be  found  that  the  acini 
of  Malpighi  in  the  former  are  identi- 
cal with  the  injected  lobular  biliary 
plexus  in  the  latter,  and  the  blood- 
vessels in  both  will  be  easily  distin- 
guished from  the  ducts. "f 

Glisson's  capsule  is  the  areolo- 
fibrous  tissue  which  envelopes  the  he- 
patic artery,  portal  vein,  and  hepatic 
duct,  during  their  passage  through  the 
right  border  of  the  lesser  omentum, 
and  which  continues  to  surround  them 
to  their  ultimate  distribution  in  the 
substance  of  the  lobules.  It  forms  for 

•  Horizontal  section  of  three  superficial  lobules,  showing  the  two  principal  systems 
o»  blood-vessels. — (Kiernan.~) 

•j-  The  Anatomy  and  Physiology  of  the  Liver,  by  Mr.  Kiernan,  Phil.  Tran,s.  1833, 
Irom  which  this  and  the  other  paragraphs  within  inverted  commas,  on  the  structure  of 
Oie  liver,  are  quoted 


Fig.  230.« 


STRUCTURAL    ANATOMY    OF    THE    LIVER. 


521 


each  lobule  a  distinct  capsule,  which  invests  it  on  all  sides  with  the  ex- 
ception of  its  base,  connects  all  the  lobules  together,  and  constitutes  the 
proper  capsule  of  the  entire  organ.  But  Glisson's  capsule  is  not  mere 
areolar  tissue ;  "  it  is  to  the  liver  what  the  pia  mater  is  to  the  brain  ;  it  is  a 
cellulo-vascular  membrane,  in  which  the  vessels  divide  and  subdivide  to 
an  extreme  degree  of  minuteness ;  which  lines  the  portal  canals,  forming 
sheaths  for  the  larger  vessels  contained  in  them,  and  a  web  in"\vhich 
the  smaller  vessels  ramify ;  which  enters  the  interlobular  fissures,  and  with 
the  vessels  forms  the  capsules  of  the  lobules ;  and  which  finally  enters  the 
lobules,  and  with  the  blood-vessels  expands  itself  over  the  secreting  biliary 
ducts."  Hence  arises  a  natural  division  of  the  capsule  into  three  portions, 
a  vaginal,  an  interlobular,  and  a  lobular  portion. 

The  vaginal  portion  is  that  which  invests  the  hepatic  artery,  hepatic 
duct,  and  portal  vein,  in  the  portal  canals ;  in  the  larger  canals  it  com- 
pletely surrounds  these  vessels,  but  in  the  smaller  is  situated  only  on  that 
side  which  is  occupied  by  the  artery  and  duct.  The  interlobular  portion 
occupies  the  interlobular  fissures  and  spaces,  and  the  lobular  portion  forms 
the  supporting  tissue  to  the  substance  of  the  lobules. 

The  Portal  vein,  entering  the  liver  at  the  transverse  fissure,  ramifies 
through  its  structure  in  canals,  which  resemble,  by  their  surfaces,  the  ex- 
ternal superficies  of  the  liver,  and  are  formed  by  the  capsular  surfaces  of 
the  lobules.  These  are  the  portal  canals,  and  contain,  besides  the  portal 
vein  with  its  ramifications,  the  artery  and  duct  with  their  branches. 

In  the  larger  canals,  the  vessels  are  separated  from  the  parietes  by  a 
web  of  Glisson's  capsule  ;  but,  in  the  smaller,  the  portal  vein  is  in  contact 
with  the  surface  of  the  canal  for  about  two-thirds  of  its  cylinder,  the  oppo- 
site third  being  in  relation  with  the  artery  and  duct  and  their  investing 
capsule.  If,  therefore,  the  portal  vein  were  laid  open  by  a  longitudinal 
incision  in  one  of  these'  smaller  canals,  the  coats  being  transparent,  the 
outline  of  the  lobules,  bounded  by  their  interlobular  fissures,  would  be  as 
distinctly  seen  as  upon  the  external  surface  of  the  liver,  and  the  smaller 
venous  branches  would  be  observed  entering  the  interlobular  spaces. 

The  branches  of  the  portal  vein 

are,  the  vaginal,  interlobular,  and  Fi&-  231-* 

lobular.  The  vaginal  branches 
are  those  which,  being  given  off 
in  the  portal  canals,  have  to  pass  2, 
through  the  sheath  (vagina)  of 
Glisson's  capsule,  previously  to 
entering  the  interlobular  spaces. 
In  this  course  they  form  an  intri- 
cate plexus,  the  vaginal  plexus, 
which,  depending  for  its  exist- 
ence on  the  capsule  of  Glisson, 
necessarily  surrounds  the  vessels, 
as  does  that  capsule  in  the  larger  canals,  and  occupies  the  capsular  side 
only  in  the  smaller  canals.  The  interlobular  branches  are  given  off  from 
the  vaginal  portal  plexus  where  it  exists,  and  directly  fronr  the  portal 
veins,  in  that  part  of  the  smaller  canals  where  the  coats  of  the  vein  are  in 
contact  with  the  walls  of  the  canal.  They  then  enter  the  interlobular 

*  Horizontal  section  of  two  superficial  lobules,  showing  interlobular  plexus  of  biliary 
ducts. — (Kiernan.) 

44* 


522  STRUCTURAL    ANATOMY    OF   THE    LIVER. 

»»spaces  and  divide  into  branches,  which  cover  with  their  ramifications 
every  part  of  the  surface  of  the  lobules,  with  the  exception  of  their  bases 
and  those  extremities  of  the  superficial  lobules  which  appear  upon  the 
surfaces  of  the  liver.  The  interlobular  veins  communicate  freely  with  each 
other,  and  with  the  corresponding  veins  of  adjoining  fissures,  and  establish 
a  general  portal  anastomosis  throughout  the  entire  liver.  The  lobulur 
branches  are  derived  from  the  interlobular  veins ;  they  form  a  plexus  with- 
in each  lobule,  and  converge  from  the  circumference  towards  the  centre, 
where  they  terminate  in  the  minute  radicles  of  the  intralobular  vein. 
"  This  plexus,  interposed  between  the  interlobular  portal  veins  and  the 
intralobular  hepatic  vein,  constitutes  the  venous  part  of  the  lobule,  and 
may  be  called  the  lobular  venous  plexus."  The  irregular  islets  of  the  sub- 
stance of  the  lobules,  seen  between  the  meshes  of  this  plexus  by  means  of 
the  microscope,  are  the  acini  of  Malpighi,  and  are  portions  of  the  lobular 
biliary  plexus. 

The  portal  vein  returns  the  venous  blood  from  the  chylopoietic  viscera, 
to  be  circulated  through  the  lobules ;  it  also  receives  the  venous  blood 
which  results  from  the  distribution  of  the  hepatic  artery. 

The  Hepatic  duct,  entering  the  liver  at  the  transverse  fissure,  divides 
into  branches,  which  ramify  through  the  portal  canals,  with  the  portal  vein 
and  hepatic  artery,  to  terminate  in  the  substance  of  the  lobules.  Its 
branches,  like  those  of  the  portal  vein,  are  vaginal,  interlobular,  and 
lobular. 

The  Vaginal  branches  ramify  through  the  capsule  of  Glisson,  and  form 
a  vaginal  biliary  plexus,  which,  like  the  vaginal  portal  plexus,  surrounds 
the  vessels  in  the  large  canals,  but  is  deficient  on  that  side  of  the  smaller 
canals  near  which  the  duct  is  placed.  The  branches  given  off  by  the 
vaginal  biliary  plexus  are  interlobular  and  lobular.  The  interlobular 
branches  proceed  from  the  vaginal  biliary  plexus  where  it  exists,  and 
directly  from  the  hepatic  duct  on  that  side  of  the  smaller  canals  against 
which  the  duct  is  placed.  They  enter  the  interlobular  spaces,  and  ramify 
upon  the  capsular  surface  of  the  lobules  in  the  interlobular  fissures,  where 
they  communicate  freely  with  each  other.  The  lobular  ducts  are  derived 
chiefly  from  the  interlobular ;  but  to  those  lobules  forming  the  walls  of  the 
portal  canals,  they  pass  directly  from  the  vaginal  plexus.  They  enter  the 
lobule,  and  form  a  plexus  in  its  interior,  the  lobular  biliary  plexus,  which 
constitutes  the  principal  part  of  the  substance  of  the  lobule.  The  ducts 
terminate  either  in  loops  or  in  csecal  extremities. 

The  coats  of  the  ducts  are  very  vascular,  and  are  supplied  with  a  num- 
ber of  mucous  follicles,  \vhich  are  distributed  irregularly  in  the  larger,  but 
are  arranged  in  two  parallel  longitudinal  rows  in  the  smaller  ducts. 

The  Hepatic  artery  enters  the  liver  with  the  portal  vein  and  hepatic 
duct,  and  ramifies  with  those  vessels  through  the  portal  canals.  Its 
branches  are  the  vaginal,  interlobular,  and  lobular.  The  vaginal  branches, 
like  those  of  the  portal  vein  and  hepatic  uuct,  form  a  vaginal  plexus,  which 
exists  throughout  the  whole  extent  of  the  portal  canals,  with  the  exception 
of  that  side  of  the  smaller  canals  which  corresponds  with  the  artery.  The 
interlobular  branches,  arising  from  the  vaginal  plexus  and  from  the  parietal 
side  of  the  artery  (in  the  smaller  canals),  ramify  through  the  interlobular 
fistmres,  and  are  principally  distributed  to  the  coats  of  the  interlobular 
ducts. 

"  From  the  superficial  interlobular  fissures  small  arteries  emerge,  and 


STRUCTURAL    ANATOMY    OF    THE    LIVER.  523 

ramify  in  the  proper  capsule,  on  the  convex  and  concave  surface  of  the 
liver,  and  in  the  ligaments.  These  are  the  capsular  arteries."  Where 
the  capsule  is  well  developed,  "  these  vessels  cover  the  surfaces  of  the 
liver  with  a  beautiful  plexus,"  and  "  anastomose  with  branches  of  the 
phrenic,  internal  mammary,  and  supra-renal  arteries,"  and  with  the  epi- 
gastric. 

The  Lobular  branches,  extremely  minute  and  few  in  number,  are  the 
nutrient  vessels  of  the  lobules,  and  terminate  in  the  lobular  venous  plexus. 

All  the  venous  blood  resulting  from  the  distribution  of  the  hepatic 
artery,  even  that  from  the  vasa  vasorum  of  the  hepatic  veins,  is  returned 
into  the  portal  vein. 

The  Hepatic  veins  commence  in  the  substance  of  each  lobule  by  minute 
venules,  which  receive  the  blood  from  the  lobular  venous  plexus,  and 
converge  to  form  the  intralobular  vein.  The  intralobular  vein  passes 
through  the  central  axis  of  the  lobule,  and  through  the  middle  of  its  base, 
to  terminate  in  a  sublobular  vein  ;  and  the  union  of  the  sublobular  veins 
constitutes  the  hepatic  trunks,  which  open  into  the  inferior  vena  cava. 
The  hepatic  venous  system  consists,  therefore,  of  three  sets  of  vessels ; 
intralobular  veins,  sublobular  veins,  and  hepatic  trunks. 

The  Sublobular  veins  are  contained  in  canals  formed  solely  by  the  bases 
of  the  lobules,  with  which,  from  the  absence  of  Glisson's  capsule,  they  are 
in  immediate  contact.  Their  coats  are  thin  and  transparent ;  and,  if  they 
be  laid  open  by  a  longitudinal  incision,  the  bases  of  the  lobules  will  be 
distinctly  seen,  separated  by  interlobular  fissures,  and  perforated  through 
the  centre  by  the  opening  of  the  intralobular  vein. 

The  Hepatic  trunks  are  formed  by  the  union  of  the  sublobular  veins ; 
they  are  contained  in  canals  (hepatic-venous)  similar  in  structure  to  the 
portal  canals,  and  lined  by  a  prolongation  of  the  proper  capsule.  They 
proceed  from  before  backwards,  and  terminate,  by  two  large  openings 
(corresponding  to  the  right  and  left  lobe  of  the  liver)  and  several  smaller 
apertures,  in  the  inferior  vena  cava. 

Summary. — The  liver  has  been  shown  to  be  composed  of  lobules  ;  the 
lobules  (excepting  at  their  bases)  are  invested  and  connected  together, 
the  vessels  supported,  and  the  whole  organ  enclosed,  by  Glisson's  capsule, 
and  they  are  so  arranged,  that  the  base  of  every  lobule  in  the  liver  is  in 
contact  with  an  hepatic  vein  (sublobular). 

The  Portal  vein  distributes  its  numberless  branches  through  portal 
canals,  which  are  channeled  through  every  part  of  the  organ ;  it  brings  the 
returning  blood  from  the  chylopoietic  viscera ;  it  collects  also  the  venous 
blood  from  the  ultimate  ramifications  of  the  hepatic  artery  in  the  liver 
itself.  It  gives  off  branches  in  the  canals,  which  are  called  vaginal,  and 
form  a  venous  vaginal  plexus;  these  give  off  interlobular  branches,  and 
the  latter  enter  the  lobules  and  form  lobular  venous  plexuses,  from  the 
blood  circulating  in  which  the  bile  is  secreted. 

The  Bile  in  the  lobule  is  received  by  a  network  of  minute  ducts,  the 
lobular  biliary  plexus  ;  it  is  conveyed  from  the  lobule  into  the  interlobular 
ducts ;  it  is  thence  poured  into  the  biliary  vaginal  plexus  of  the  portal 
canals,  and  thence  into  the  excreting  ducts,  by  which  it  is  carried  to  the 
duodenum  and  gall-bladder,  after  being  mingled  in  its  course  with  the 
mucous  secretion  from  the  numberless  muciparous  follicles  in  the  walls  of 
the  ducts. 

The  Hepatic  artery  distributes  branches  through  every  Dortal  cana. ; 


524  STRUCTURAL    ANATOMY    OF    THE    LIVER. 

gives  off  vaginal  branches  which  form  a  vaginal  hepatic  plexus,  from 
which  the  interlobular  brandies  arise,  and  these  latter  terminate  ultimately 
in  the  lobular  venous  plexuses  of  the  portal  vein.  The  artery  ramifies 
abundantly  in  the  coats  of  the  hepatic  ducts,  enabling  them  to  provide 
their  mucous  secretion ;  and  supplies  the  vasa  vasorum  of  the  portal  and 
hepatic  veins,  and  the  nutrient  vessels  of  the  entire  organ. 

The  Hepatic  veins  commence  in  the  centre  of  each  lobule  by  minute 
radicles,  which  collect  the  impure  blood  from  the  lobular  venous  plexus 
and  convey  it  into  the  intralobular  veins ;  these  open  into  the  sublobular 
veins,  and  the  sublobular  veins  unite  to  form  the  large  hepatic  trunks  by 
which  the  blood  is  conveyed  into  the  vena  cava. 

Physiological  and  Pathological  Deductions.  —  The  physiological  deduc- 
tion arising  out  of  this  anatomical  arrangement  is,  that  the  bile  is  wholly 
secreted  from,  venous  blood,  and  not  from  a  mixed  venous  and  arterial 
blood,  as  stated  by  Miiller;  for  although  the  portal  vein  receives  its  blood 
from  two  sources,  viz.  from  the  chylopoietic  viscera  and  from  the  capil- 
laries of  the  hepatic  artery,  yet  the  very  fact  of  the  blood  of  the  latter 
vessel  having  passed  through  its  capillaries  into  the  portal  vein,  or  in  ex- 
tremely small  quantity  into  the  capillary  network  of  the  lobular  venous 
plexus,  is  sufficient  to  establish  its  venous  character.* 

The  pathological  deductions  depend  upon  the  following  facts:  — Each 
lobule  is  a  perfect  gland ;  of  uniform  structure,  of  uniform  colour,  and 
possessing  the  same  degree  of  vascularity  throughout.  It  is  the  seat  of  a 
double  venous  circulation,  the  vessels  of  the  one  (hepatic)  being  situated 
in  the  centre  of  the  lobule,  and  those  of  the  other  (portal)  in  the  circum- 
ference. Now  the  colour  of  the  lobule,  as  of  the  entire  liver,  depends 
chiefly  upon  the  proportion  of  blood  contained  within  these  two  sets  of 
vessels ;  and  so  long  as  the  circulation  is  natural,  the  colour  will  be  uni- 
form. But  the  instant  that  any  cause  is  developed  which  shall  interfere 
with  the  free  circulation  of  either,  there  will  be  an  immediate  diversity  in 
the  colour  of  the  lobule. 

Thus,  if  there  be  any  impediment  to  the  free  circulation  of  the  venous 
blood  through  the  heart  or  lungs,  the  circulation  in  the  hepatic  veins  will 
be  retarded,  and  the  sublobular  and  the  intralobular  veins  will  become 
congested,  giving  rise  to  a  more  or  less  extensive  redness  in  the  centre  of 
each  of  the  lobules,  while  the  marginal  or  non-congested  portion  presents 
a  distinct  border  of  a  yellowish  white,  yellow,  or  green  colour,  according 
to  the  quantity  and  quality  of  the  bile  it  may  contain.  "  This  is  'passive 
congestion*  of  the  liver,  the  usual  and  natural  state  of  the  organ  after  death ;" 
and,  as  it  commences  with  the  hepatic  vein,  it  maybe  called  the  first  stage 
of  hepatic-venous  congestion. 

But  if  the  causes  which  produced  this  state  of  congestion  continue,  or 
be  from  the  beginning  of  a  more  active  kind,  the  congestion  will  extend 
through  the  lobular  venous  plexuses  "  into  those  branches  of  the  portal 
vein  situated  in  the  interlobular  fissures,  but  not  to  those  in  the  spaces, 
which  being  larger,  and  giving  origin  to  those  in  the  fissures,  are  the  last 
to  be  congested."  In  this  second  stage  the  liver  has  a  mottled  appear- 
ance, the  non-congested  substance  is  arranged  in  isolated,  circular,  anc1 
ramose  patches,  in  the  centres  of  which  the  spaces  and  parts  of  the  fissures 
are  seen.  This  is  an  extended  degree  of  hepatic-venous  congestion ;  it  is 

*  For  arguments  on  this  contested  question,  see  the  article  "  Liver."  in  the  "  Cyclo 
psti:a  of  Anatomy  and  Physiology,1'  edited  by  Dr.  Todd. 


GALL-BLADDER.  525 

"  active  congestion"  of  the  liver,  and  very  commonly  attends  disease  of  the 
heart  and  lungs. 

These  are  instances  of  partial  congestion,  but  there  is  sometimes  general 
congestion  of  the  organ.  "  In  general  congestion  the  whole  liver  is  of  a 
red  colour,  but  the  central  portions  of  the  lobules  are  usually  of  a  deeper 
hue  than  the  marginal  portions." 

GALL-BLADDER. 

The  Gall-bladder  (fig.  166)  is  the  reservoir  of  the  bile ;  it  is  a  pyriform 
sac,  situated  in  a  fossa  on  the  under  surface  of  the  right  lobe  of  the  liver, 
and  extending  from  the  right  extremity  of  the  transverse  fissure  to  the  free 
margin.  It  is  divided  into  a  body,  fundus,  and 'neck :  the  fundus  or  broad 
extremity  in  the  natural  position  of  the  liver  is  placed  downwards,  and 
frequently  projects  beyond  the  free  margin  of  the  liver,  while  the  neck, 
small  and  constricted,  is  directed  upwards.  This  sac  is  composed  of  three 
coats,  serous,  fibrous,  and  mucous.  The  serous  coat  is  partial,  is  derived 
from  the  peritoneum,  and  covers  that  side  only  which  is  unattached  to  the 
liver.  The  middle  or  fibrous  coat  is  a  thin  but  strong  fibrous  layer,  con- 
nected on  one  side  to  the  liver,  and  on  the  other  to  the  peritoneum.  The 
internal  or  mucous  coat  is  but  loosely  attached  to  the  fibrous  layer ;  it  is 
everywhere  raised  into  minute  rugae,  which  give  it  a  beautifully  reticulated 
appearance,  and  forms,  at  the  neck  of  the  sac,  a  spiral  valve.  It  is  con- 
tinuous through  the  hepatic  duct  with  the  mucous  membrane  lining  all  the 
ducts  of  the  liver,  and  through  the  ductus  communis  choledochus,  with 
tlie  mucous  membrane  of  the  alimentary  canal. 

The  Biliary  ducts  are,  the  ductus  communis  choledochus,  the  cystic, 
and  the  hepatic  duct. 

The  Ductus  communis  choledochus  (x°^  bills,  ^ofxai  recipio)  is  the 
common  excretory  duct  of  the  liver  and  gall-bladder ;  it  is  about  three 
inches  in  length,  and  commences  at  the  papilla  situated  on  the  inner  side 
of  the  cylinder  of  the  perpendicular  portion  of  the  duodenum.  Passing 
obliquely  between  the  mucous  and  muscular  coat,  it  ascends  behind  the 
duodenum,  and  through  the  right  border  of  the  lesser  omentum ;  and 
divides  into  two  branches,  the  cystic  duct  and  the  hepatic  duct.  It  is 
constricted  at  its  commencement  in  the  duodenum,  and  becomes  dilated 
in  its  progress  upwards. 

The  Cystic  duct,  about  an  inch  in  length,  passes  outwards  from  the 
preceding  to  the  neck  of  the  gall-bladder,  with  which  it  is  continuous. 

The  Hepatic  duct  continues  onwards  to  the  transverse  fissure  of  the  liver, 
and  divides  into  two  branches,  which  ramify  through  the  portal  canals  to 
every  part  of  the  liver. 

The  coats  of  the  hepatic  ducts  are  an  external  or  fibrous,  and  an  internal 
or  mucous  coat.  The  external  coat  is  composed  of  a  contractile  fibrous 
tissue,  which  is  probably  muscular ;  but  its  muscularity  has  not  yet  been 
demonstrated  in  the  human  subject.  The  mucous  coat  is  continuous  on 
the  one  hand  with  the  lining  membrane  of  the  hepatic  ducts  and  gall 
bladder,  and  on  the  other  with  that  of  the  duodenum. 

Vessels  and  Nerves.  —  The  gall-bladder  is  supplied  with  blood  by_thr 
cystic  artery,  a  branch  of  the  hepatic.  Its  veins  return  their  blood  into 
the  portal  vein.  The  nerves  are  derived  from  the  hepatic  plexus. 


526  PANCREAS — SPLEEN. 


THE    PANCREAS. 

The  pancreas  is  a  long,  flattened,  conglomerate  gland,  analogous  to  the 
salivary  glands.  It  is  about  six  inches  in  length,  and  between  three  ind 
four  ounces  in  weight ;  is  situated  transversely  across  the  posterior  wall 
of  the  abdomen,  behind  the  stomach,  and  resting  on  the  aorta,  vena  portae, 
inferior  vena  cava,  the  origin  of  the  superior  mesenteric  artery,  and  the  left 
kidney  and  supra-renal  capsule ;  opposite  the  first  and  second  lumbar 
vertebrae.  It  is  divided  into  a  body,  a  greater  and  a  smaller  extremity : 
the  great  end  or  head  is  placed  towards  the  right,  and  is  surrounded  by 
the  curve  of  the  duodenum ;  the  lesser  end  extends  to  the  left  as  far  as 
the  spleen.  The  anterior  surface  of  the  body  of  the  pancreas  is  covered 
by  the  ascending  posterior*  layer  of  peritoneum,  and  is  in  relation  with  the 
stomach,  the  first  portion  of  the  duodenum,  and  the  commencement  of  the 
transverse  arch  of  the  colon.  The  posterior  surface  is  grooved  for  the 
splenic  vein,  and  tunnelled  by  a  complete  canal  for  the  superior  mesenteric 
and  portal  vein,  and  superior  mesenteric  artery.  The  upper  border  pre- 
sents a  deep  groove,  sometimes  a  canal,  for  the  splenic  artery  and  vein, 
and  is  in  relation  with  the  oblique  portion  of  the  duodenum,  the  lobus 
Spigelii,  and  cceliac  axis.  And  the  lower  border  is  separated  from  the 
transverse  portion  of  the  duodenum  by  the  superior  mesenteric  artery  and 
vein.  Upon  the  posterior  part  of  the  head  of  the  pancreas  is  a  lobular  fold 
of  the  gland  which  completes  the  canal  of  the  superior  mesenteric  vessels, 
and  is  called  the  lesser  pancreas. 

In  structure,  the  pancreas  is  composed  of  reddish-yellow  polyhedral 
lobules  ;  these  consist  of  smaller  lobules,  and  the  latter  are  made  up  of  the 
arborescent  ramifications  of  minute  ducts,  terminating  in  ca?cal  pouches. 

The  pancreatic  duct  commences  at  the  papilla  on  the  inner  and  posterior 
surface  of  the  perpendicular  portion  of  the  duodenum  by  a  small  dilatation 
which  is  common  to  it  and  the  ductus  communis  choledochus,  and,  pass- 
ing obliquely  between  the  mucous  and  muscular  coats,  runs  from  right  to 
left  through  the  middle  of  the  gland,  lying  nearer  its  anterior  than  its  pos- 
terior surface.  At  about  the  commencement  of  the  apicial  third  of  its 
course  it  divides  into  two  parallel  terminal  branches.  The  duct  gives  off 
numerous  small  branches,  which  are  distributed  through  the  lobules,  and 
constitute,  with  the  latter,  the  substance  of  the  gland.  The  duct  which 
receives  the  secretion  from  the  lesser  pancreas  is  called  the  ductus  pancre- 
aticus  minor;  it  opens  in  the  principal  duct  near  the  duodenum,  and  some- 
times passes  separately  into  that  intestine.  A^  a  variety,  two  pancreatic 
ducts  are  occasionally  met  with. 

Vessels  and  Nerves. — The  arteries  of  the  pancreas  are  branches  of  the 
splenic,  hepatic,  and  superior  mesenteric  ;  the  veins  open  into  the  splenic 
vein ;  the  lymphatics  terminate  in  the  lumbar  glands.  The  nerves  are  fila- 
ments of  the  splenic  plexus. 

THE    SPLEEN. 

Tne  spleen  is  an  oblong  flattened  organ,  of  a  dark  bluish-red  colour, 
situated  in  the  left  hypochondriac  region.  It  is  variable  in  size  and  weight, 
spongy  and  vascular  in  texture,  and  exceedingly  friable.  The  external 
surface  is  convex,  the  internal  slightly  concave,  indented  along  the  middle 
line,  and  pierced  by  several  large  and  irrf  q^ular  openings  for  the  entrance 


THE    SUPRA-RENAL    CAPSULES.  527 

and  exit  of  vessels  ;  this  is  the  hilus  lienis.  The  upper  extremity  is  some- 
what larger  than  the  lower,  and  rounded;  the  inferior  is  flattened;  the 
posterior  border  is  obtuse,  the  anterior  is  sharp,  and  marked  by  several 
notches.  The  spleen  is  in  relation  by  its  external  or  convex  surface  with 
the  diaphragm,  which  separates  it  from  the  ninth,  tenth,  and  eleventh  ribs; 
by  its  concave  surface,  with  the  great  end  of  the  stomach,  the  extremity 
of  the  pancreas,  the  gastro-splenic  omentum  and  its  vessels,  the  left  kidney 
and  supra- renal  capsule,  and  the  left  crus  of  the  diaphragm  ;  by  its  upper 
end  with  the  diaphragm,  and  sometimes  with  the  extremity  of  the  left  lobe 
of  the  liver ;  and,  by  its  lower  end,  with  the  left  extremity  of  the  transverse 
arch  of  the  colon.  It  is  connected  to  the  stomach  by  the  gastro-splenic 
omentum,  and  by  the  vessels  contained  in  that  duplicature.  A  second 
spleen  (lien  succenturiatus)  is  sometimes  found  appended  to  one  of  the 
branches  of  the  splenic  artery,  near  the  great  end  of  the  stomach ;  when 
it  exists,  it  is  round  and  of  small  size,  rarely  larger  than  a  hazel-nut.  I 
have  seen  two,  and  even  three,  of  these  bodies.  The  spleen  is  invested 
by  the  peritoneum  and  by  a  tunica  propria  of  yellow  elastic  tissue,  which 
enables  it  to  yield  to  the  greater  or  less  distension  of  its  vessels.  The 
elastic  tunic  forms  sheaths  for  the  vessels  in  their  ramifications  through  the 
organ,  and  from  these  sheaths  small  fibrous  bands  are  given  off  in  all  di- 
rections, which  become  attached  to  the  internal  surface  of  the  elastic  tunic, 
and  constitute  the  areolar  framework  of  the  spleen.  The  substance  occu- 
pying the  interspaces  of  this  tissue  is  soft,  granular,  and  of  a  bright  red 
colour ;  and  frequently  interspersed  with  small,  white,  soft  corpuscles 
(Malpighian  bodies).  These  corpuscles,  according  to  the  researches  of 
Oesterlen  and  Mr.  Simon,  are  aggregations  of  cyto-blasts  enclosed  in  a 
kind  of  capsule  of  capillary  vessels.  There  are,  besides,  separate  cyto- 
blasts  scattered  through  the  red  substance. 

Vessels  and  Nerves. — The  Splenic  artery  is  of  very  large  size  in  propor- 
tion to  the  bulk  of  the  spleen  ;  it  is  a  division  of  the  coeliac  axis.  The 
branches  which  enter  the  spleen  are  distributed  to  distinct  sections  of  the 
organ,  and  anastomose  very  sparingly  with  each  other.  The  veins  by  their 
numerous  dilatations  constitute  the  principal  part  of  the  bulk  of  the  spleen ; 
they  pour  their  blood  into  the  splenic  vein,  which  is  one  of  the  two  great 
formative  trunks  of  the  portal  vein.  The  lympliaiics  are  remarkable  for 
their  number  and  large  size  ;  they  terminate  in  the  lumbar  glands.  The 
nerves  are,  the  splenic  plexus,  derived  from  the  solar  plexus. 


THE  SUPRA-RENAL  CAPSULES. 

The  supra-renal  capsules  are  two  small  yellowish  and  flattened  bodies 
surmounting  the  kidneys,  and  inclining  inwards  towards  the  vertebral 
column.  The  right  is  somewhat  three-cornered  in  shape,  the  left  serai- 
lunar  ;  they  are  connected  to  the  kidneys  by  the  common  investing  areolar 
tissue,  and  each  capsule  is  marked  on  its  anterior  surface  by  a  fissure 
which  appears  to  divide  it  into  two  lobes.  The  right  supra-renal  capsule 
is  closely  adherent  to  the  posterior  and  under  surface  of  the  liver,  and  the 
left  lies  in  contact  with  the  pancreas.  Both  capsules  rest  against  the  crurn 
of  the  diaphragm  on  a  level  with  the  tenth  dorsal  vertebra,  and,  by  their 
inner  border,  are  in  relation  with  the  great  splanchnic  nerve  and  semilunar 
ganglion.  They  are  larger  in  the  fetus  than  in  the  adult,  and  appear  to 


528  THE   KIDNEYS. 

perform  some  office  connected  with  embryonic  life.  The  anatomy  of  these 
organs  in  the  foetus  will  be  found  in  the  succeeding  chapter. 

In  structure  they  are  composed  of  two  substances,  cortical  and  medul- 
lary. The  cortical  substance  is  of  a  yellowish  colour,  and  consists  of 
straight  parallel  columns  placed  perpendicularly  side  by  side.  The  me- 
dullary substance  is  generally  of  a  dark  brown  colour,  double  the  quantity 
of  the  yellow  substance,  soft  and  spongy  in  texture,  and  contains  within 
its  centre  the  trunk  of  a  large  vein,  the  vena  supra-renalis.  It  is  the  large 
size  of  this  vein  that  gives  to  the  fresh  supra-renal  capsule  the  appearance 
of  a  central  cavity :  the  dark-coloured  pulpy  or  fluid  contents  of  the  cap- 
sule, at  a  certain  period  after  death,  are  produced  by  softening  of  the  me- 
dullary substance.  Dr.  Nagel*  has  shown,  by  his  injections  and  micro- 
scopic examinations,  that  the  appearance  of  columns  in  the  cortical  substance 
is  caused  by  the  direction  of  a  plexus  of  capillary  vessels.  Of  the  numer- 
ous minute  arteries,  supplying  the  supra-renal  capsule,  he  says,  the  greater 
number  enter  the  cortical  substance  at  every  point  of  its  surface,  and,  after 
proceeding  for  scarcely  half  a  line,  divide  into  a  plexus  of  straight  capil- 
lary vessels.  Some  few  of  the  small  arteries  traverse  the  cortical  layer, 
and  give  off,  in  the  medullary  substance,  several  branches  which  proceed 
in  different  directions,  and  re-enter  the  cortical  layer  to  divide  into  a  ca- 
pillary plexus  in  a  similar  manner  with  the  first  described.  From  the 
capillary  plexus,  composing  the  cortical  layer,  the  blood  is  received  by 
numerous  small  veins  which  form  a  venous  plexus  in  the  medullary  sub- 
stance, and  terminate  at  acute  angles  in  the  large  central  vein. 

According  to  the  more  recent  researches  of  Oesterlen  and  Mr.  Simon, 
the  appearance  of  columns  is  due  to  groups  of  small  corpuscles  or  cyto- 
blasts  associated  with  elementary  granules  and  fat-cells  collected  together 
in  the  form  of  parallel  cylinders  or  cones,  each  group  being  enclosed  in  a 
tube  of  delicate  membrane  (limitary  membrane).  The  medullary  sub- 
stance and  intercolumnar  spaces  contain  cyto-blasts  uniformly  scattered 
and  interspersed  with  granules  and  fat-cells.  Oesterlen  found  also,  occa- 
sionally, in  the  medullary  substance  elongated  spaces,  without  lining 
membrane,  containing  a  thick  greyish- white  fluid. 

Vessels  and  Nerves. — The  supra-renal  arteries  are  derived  from  the 
aorta,  from  the  renal,  and  from  the  phrenic  arteries ;  they  are  remarkable 
for  the  innumerable  minute  twigs  into  which  they  divide  previously  to 
entering  the  capsule.  The  supra-renal  vein  collecting  the  blood  from  thf 
medullary  venous  plexus,  and  receiving  several  branches  which  pierce  the 
cortical  layer,  opens  directly  into  the  vena  cava  on  the  right  side,  and  into 
the  renal  vein  on  the  left. 

The  Lymphatics  are  large  and  very  numerous ;  they  terminate  in  the 
lumbar  glands.  The  nerves  are  derived  from  the  renal  and  from  the 
phrenic  plexus. 

THE    KIDNEYS. 

Tb*  kidneys,  the  secreting  organs  of  the  urine,  are  situated  in  the  lum- 
Imr  regions,  behind  the  peritoneum,  and  on  each  side  of  the  vertebral 
column,  which  latter  they  approach  by  their  upper  extremities.  Each 
kidney  is  between  four  and  five  inches  in  length,  about  two  inches  and  a 
half  in  breadth,  somewhat  more  than  one  inch  in  thickness,  and  weighs 
between  three  and  five  ounces.  The  kidneys  are  usually  enclosed  in  3 

•Muller's  Archiv.  1830.  * 


STRUCTURE    OF   THE    KIDNEYS. 


529 


Fig.  232* 


quantity  of  fat ;  they  rest  on  the  diaphragm,  on  the  anterior  lamella  of  the 
transversalis  muscle,  which  separates  them  from  the  quadratus  lumborum 
and  on  the  psoas  magnus.  The  right  /ddney  is  somewhat  lower  than  the 
left,  from  the  position  of  the  liver ;  it  is  in  relation,  by  its  anterior  surface 
with  the  liver  and  descending  portion  of  the  duodenum,  which  rest  against 
it ;  and  it  is  covered  in  by  the  ascending  colon  and  by  its  flexure.  °  The 
left  kidney,  higher  than  the  right,  is  covered,  in  front,  by  the  great  end 
of  the  stomach,  by  the  spleen,  descending  colon  with  its  flexure,  and  by 
a  portion  of  the  small  intestines.  The  anterior  surface  of  the  kidney  is 
convex,  \vhile  the  posterior  is  flat ;  the  superior  extremity  is  in  relation 
with  the  supra-renal  capsule  ;  the  convex  border  is  turned  outwards  to- 
wards the  parietes  of  the  abdomen ;  the  concave  border  looks  inwards 
towards  the  vertebral  column,  and  is  excavated 
by  a  deep  fissure,  the  hilus  renalis,  in  which  are 
situated  the  vessels  and  nerves  and  pelvis  of  the 
kidney ;  the  renal  vein  being  the  most  anterior, 
next  the  renal  artery,  and  lastly  the  pelvis. 

The  kidney  is  dense  and  fragile  in  texture,  and 
is  invested  by  a  proper  fibrous  capsule,  which  is 
easily  torn  from,  its  surface.  When  divided  by  a 
longitudinal  incision,  carried  from  the  convex  to 
the  concave  border,  it  is  found  to  present  in  its 
interior  two  structures,  an  external  or  vascular 
(cortical),  and  an  internal  or  tubular  (medullary) 
substance.  The  tubular  portion  is  formed  of  pale 
reddish-coloured  conical  masses,  corresponding 
by  their  bases  with  the  vascular  structure,  and  by 
their  apices  with  the  hilus  of  the  organ  ;  these 
bodies  are  named  cones  (pyramids  of  Malpighi), 
and  are  from  eight  to  fifteen  in  number.  The  vascular  portion  is  com- 
posed of  blood-vessels  and  of  the  plexiform  convolutions  of  uriniferous 
tubuli,  and  not  only  constitutes  the  surface  of  the  kidney,  but  dips  be- 
tween the  cones  and  surrounds  them  nearly  to  their  apices. 

The  cones  or  pyramids  of  the  tubular  portion  of  the  kidney  are  com- 
posed of  minute  straight  tubuli  uriniferi,  of  about  the  diameter  of  a  fine 
hair.  The  tubuli  commence  at  the  apices  of  the  cones,  and  pursue  a  pa- 
rallel course  towards  the  periphery  of  the  organ,  bifurcating  from  point  to 
point,  and  separated  only  by  minute  straight  blood-vessels,  and  a  small 
quantity  of  parenchymatous  substance.  At  the  bases  of  the  pyramids  the 
tubuli  collect  into  smaller  conical  fasciculi,  which  are  prolonged  into  the 
substance  of  the  cortical  portion  of  the  kidney,  and  have  interposed  be- 
tween them  processes  of  the  vascular  structure.  In  the  smaller  pyramids 
the  fasciculi  separate  into  their  component  tubules,  which,  after  a  course 
marked  by  "  tortuosities,  plexuses,  convolutions,  and  dilatations,"  ter- 
minate, according  to  Mr.  Bowman, f  in  small  round  bodies,  the  corpora 

*  A  section  of  the  kidney,  surmounted  by  the  supra-renal  capsule;  the  swe-llings  on 
the  surface  mark  the  original  constitution  of  the  organ  of  distinct  lobes.  1.  The  supra 
renal  capsule.  2.  The  vascular  portion  of  the  kidney.  3,  3.  Its  tubular  portion,  con- 
sisting of  cones.  4,  4.  Two  of  the  papillae  projecting  into  their  corresponding  calices 
5.  5,  5.  The  three  infundibula;  the  middle  5  is  situated  in  the  mouth  of  a  calyx.  G. 
The  pelvis.  7.  The  ureter. 

f  On  the  Structure  and  Use  of  the  Malpighian  Bodies  of  the  Kidney.  Philosonhicu' 
Transactions,  1842. 

45  2 1 


5-30  STRUCTURE  OF  THE  KIDNEYS. 

Malpighiana,  or,  according  to  Krause  and  the  recent  investigations  of  Mr. 
Toynbee,*  by  anastomoses  and  caecal  extremities.  The  average  d;ameter 
of  the  tubuli  uriniferi  in  the  cortical  portion  of  the  kidney  is  the  ?|0  of  an 
inch,  of  \vhich  about  two-thirds  are  occupied  by  a  nucleated  epithelium, 
the  remaining  third  representing  the  area  of  the  tube.  According  to  Mr. 
Bowman,  the  epithelium  is  ciliated  in  that  part  of  the  tubule  which  is  neai 
the  Malpighian  body,  and  which,  according  to  the  same  authority,  is  very 
much  constricted. 

In  the  cortical  portion  of  the  kidney  are  contained  a  multitude  of  minute, 
red,  globular  bodies,  the  corpora  Malpighiana,  or  glomeruli.  Each  Mal- 
pighian body,  about  T^  of  an  inch  in  diameter,  is  composed  of  a  plexus 
of  capillary  vessels,  and,  in  addition,  according  to  Mr.  Toynbee,  of  a  coil 
of  an  uriniferous  tubule ;  the  tuft  of  capillaries  and  the  coil  of  the  tubule 
both  being  enclosed  in  a  thin,  membranous  capsule.  According  to  Mr. 
Bowman,  the  capsule  of  the  Malpighian  body  is  the  origin  of  the  uriniferous 
tubule  expanded  into  a  globular  form  for  the  reception  of  the  capillary 
tuft.  The  capillary  vessels  of  the  vascular  tuft  are  arranged  in  loops 
closely  packed  together,  and  surrounded  by  an  epithelium  which  is  conti- 
nuous with  a  similar  structure  lining  the  inner  surface  of  the  capsule. 
They  are  derived  from  a  small  artery,  which,  after  piercing  the  capsule, 
immediately  divides  in  a  radiated  manner  into  several  branches.  From 
the  interior  of  this  little  vascular  ball  a  vein  proceeds,  smaller  than  the 
corresponding  artery,  and  pierces  the  capsule  close  by  the  artery,  to  com- 
municate with  the  efferent  vessels  of  other  Malpighian  bodies  and  consti- 
tute a  venous  plexus. 

The  cones  or  mamillary  processes  of  the  interior  of  the  kidney  are  in- 
vested by  mucous  membrane,  which  is  continuous  at  their  apices  with  the 
uriniferous  tubuli,  and  is  reflected  from  their  sides  so  as  to  form  around 
each  a  cup-like  pouch,  or  calyx.  The  calices  communicate  with  a  com- 
mon cavity  of  larger  size,  situated  at  each  extremity,  and  in  the  middle 
of  the  organ ;  and  these  three  cavities,  the  infundibula,  constitute  by  their 
union  the  large  membranous  sac,  which  occupies  the  hilus  renalis,  the 
pelvis  of  the  kidney. 

The  kidney  in  the  embryo  and  foetus  consists  of  lobules.  See  the  ana- 
tomy of  the  fetus  in  the  succeeding  Chapter. 

The  Ureter,  (ougov,  urine,  T/^SIV,  to  keep,)  the  excretory  duct  of  the  kid- 
ney, is  a  membranous  tube  of  about  the  diameter  of  a  goose-quill,  ana 
nearly  eighteen  inches  in  length ;  it  is  continuous  superiorly  with  the  pel- 
vis of  the  kidney,  and  is  constricted  inferiorly,  where  it  lies  in  an  oblique 
direction  between  the  muscular  and  mucous  coats  of  the  base  of  the  blad- 
der, and  opens  upon  its  mucous  surface.  Lying  along  the  posterior  wall 
of  the  abdomen,  it  is  situated  behind  the  peritoneum,  and  is  crossed  by 
the  spermatic  vessels ;  in  its  course  downwards  it  rests  against  the  anterior 
surface  of  the  psoas,  and  crosses  the  common  iliac  artery  and  vein,  and 
then  the  external  iliac  vessels.  Within  the  pelvis  it  crosses  the  umbilical 
artery  and  the  vas  deferens  in  the  male,  and  the  upper  part  of  the  vagina 
in  the  female.  There  are  sometimes  two  ureters  to  one  kidney.  The 
ureter,  the  pelvis,  the  infundibula,  and  the  calices  are  composed  of  two 
coats,  an  external  or  fibrous  coat,  the  tunica  propria ;  and  an  internal 
mucous  coat,  which  is  continuous  with  the  mucous  membrane  of  the 

•  On  the  intimate  Structure  of  the  Human  Kidney.  &c.  Medico-Cliirurgical  Tranc- 
Bct:ons.  vol.  xxix.,  1846. 


PORTAL    CIRCULATION    OF   THE    KIDNEYS. 


531 


Fig.  233.' 


I >ladder   inferiorly,    and   with   that  of  the  tubuli 
uriniferi  above. 

Vessels  and  Nerves. — The  renal  artery  is  derived 
from  the  aorta ;  it  divides  into  several  large  branches 
before  entering  the  hilus,  and  within  the  organ  ra- 
mifies in  an  arborescent  manner,  terminating  in 
nutrient  twigs,  and  in  the  small  inferent  vessels  of 
the  corpora  Malpighiana.  In  the  Malpighian 
bodies  the  inferent  vessels  divide  into  several  pri- 
mary twigs,  which  subdivide  into  capillaries,  and 
the  capillaries,  after  forming  loops,  converge  to  the 
efferent  vein,  which  is  generally  smaller  than  the 
corresponding  artery.  The  efferent  veins  proceed 
to  and  form  a  capillary  venous  plexus,  which  surrounds  the  tortuous  tubuli 
uriniferi,  and  from  this  venous  plexus  the  blood  is  conveyed,  by  converg- 
ing branches,  into  the  renal  vein. 

"Thus,"  remarks  Mr.  Bowman,  "there  are  in  the  kidney  two  perfectly 
distinct  systems  of  capillary  vessels,  through  both  of  which  the  blood 
passes  in  its  course  from  the  arteries  into  the  veins :  the  first,  that"  which 
forms  the  vascular  tuft  in  the  Malpighian  bodies,  and  is  "  in  immediate 
connexion  with  the  arteries ;  the  second,  that  enveloping  the  convolutions 
of  the  tubes  and  communicating  directly  with  the  veins.  The  efferent 
vessels  of  the  Malpighian  bodies,  that  carry  the  blood  between  these  two 
systems,  may  collectively  be  termed  the  portal  system  of  the  kidney." 
The  inferences  drawn  by  Mr.  Bowman  from  his  investigations  are  interest- 
ing; they  are,  that  the  capillary  tufts  of  the  Malpighian  bodies  are  the  part 
of  the  kidney  specially  acted  on  by  diuretics ;  that  they  are  the  medium 
by  which  water,  certain  salts,  arid  other  substances,  pass  out  of  the  system ; 
that  they  are,  moreover,  the  means  of  escape  of  certain  morbid  products, 
such  as  sugar,  albumen,  and  the  red  particles  of  the  blood.  Respecting 
the  capillary  venous  plexus,  we  have  proof  that  the  principal  proximate 
constituents  of  urine,  such  as  urea,  lithic  acid,  &c.}  are,  like  the  bile,  de- 
rived from  venous  (portal)  blood. 

The  Veins  of  the  kidney  commence  at  the  surface  by  minute  converging 
venules,  the  stellated  vessels,  and  proceed  inwards,  receiving  in  their 
course  the  veins  of  the  cortical  and  tubular  portions  of  the  organ.  On 
arriving  at  the  pelvis,  they  unite  to  form  the  branches  of  the  renal  vein, 
which  terminates  in  the  vena  cava  by  a  single  large  trunk  on  each  side  ; 
the  left  renal  vein  receiving  the  left  spermatic  vein.  Injections  thrown 
into  the  renal  artery,  and  returning  by  the  tubuli  uritiif«ri,  make  their  way 
into  those  tubes  by  rupture.  The  lymphatic  vessels  terminate  in  the  lum- 
bar glands. 

The  Nerves  are  derived  from  the  renal  plexus,  which  is  formed  partly 
by  the  solar  plexus,  and  partly  by  the  lesser  splanchnic  nerve.  The  renal 
plexus  gives  branches  to  the  spermatic  plexus,  and  branches  which  accom- 

*  Plan  of  the  renal  circulation ;  copied  from  Mr.  Bowman's  paper,  a.  A  branch  of 
the  renal  artery  giving  off  several  Malpighian  twigs.  1.  An  efferent  twig  to  the  capil- 
lary tuft  contained  in  the  Malpighian  body,  m;  from  the  Malpighian  body  the  urinife- 
rotis  tube  is  seen  taking  its  tortuous  course  to  t.  2,  2.  Efferent  veins;  that  which  pro- 
ceeds from  the  Malpisrhian  body  is  seen  to  be  smaller  than  the  corresponding  artery. 
v,  p.  The  capillary  venous  plexus,  ramifying  upon  the  uriniferous  tube.  This  plexus 
receives  its  blood  from  the  efferent  veins,  2.  2,  and  transmits  it  to  the  branch  of  ti.«- 
renal  vein,  ». 


532  PELVIS — BLADDER. 

pany  the  ureters :  hence  the  morbid  sympathies  which  exist  between  tne 
kidney,  the  ureter,  and  the  testicle :  and  by  the  communications  with  the 
solar  plexus,  with  the  stomach  and  diaphragm,  and  indeed  with  the  whole 
system.  In  the  intimate  structure  of  the  kidney,  the  nerve-fibres  are,  ac- 
cording to  Mr.  Toynbee,  continuous  with  the  nucleated  cells  of  the  paren- 
chyma of  that  organ. 


PELVIS. 

i 

The  cavity  of  the  pelvis  is  that  portion  of  the  great  abdominal  cavity 
which  is  included  within  the  bones  of  the  pelvis,  below  the  level  of  the 
linea-ilio-pectinea  and  the  promontory  of  the  sacrum.  It  is  bounded  by 
the  cavity  of  the  abdomen  above,  and  by  the  perineum  below ;  its  internal 
parietes  are  formed,  in  front,  below,  and  at  the  sides,  by  the  peritoneum, 
pelvic  fascia,  levatores  ani  muscles,  obturator  fasciae,  and  muscles ;  and 
behind,  by  the  sacrum  and  sacral  plexus  of  nerves. 

The  Viscera  of  the  pelvis  in  the  male  are,  the  urinary  bladder,  the  pros- 
tate gland,  vesiculae  seminales,  and  the  rectum. 


BLADDER. 


The  Bladder  is  an  oblong  membranous  viscus  of  an  ovoid  shape,  situated 
behind  the  ossa  pubis  and  in  front  of  the  rectum.  It  is  larger  in  its  ver- 
tical diameter  than  from  side  to  side ;  and  its  long  axis  is  directed  from 
above,  obliquely  downwards  and  backwards.  It  is  divided  into,  body, 
fundus,  base,  and  neck.  The  body  comprehends  the  middle  zone  of  the 
organ ;  the  fundus,  its  upper  segment ;  the  base,  the  lower  broad  extre- 
mity which  rests  on  the  rectum;  and  the  neck,  the  narrow  constricted  por- 
tion which  is  applied  against  the  prostate  gland. 

This  organ  is  retained  in  its  place  by  ligaments,  which  are  divided  into 
true  and  false  ;  the  true  ligaments  are  seven  in  number,  two  anterior,  two 
lateral,  two  umbilical,  and  the  urachus ;  the  false  ligaments  are  folds  of 
the  peritoneum,  and  are  four  in  number,  two  anterior  and  two  posterior. 
The  anterior  ligaments  are  formed  by  the  pelvic  fascia,  which  passes  from 
the  inner  surface  of  the  os  pubis,  on  each  side  of  the  symphysis,  to  the 
front  of  the  bladder.  The  lateral  ligaments  are  formed  by  the  reflexion 
of  the  pelvic  fascia  from  the  levatores  ani  muscles,  upon  the  sides  of  the 
base  of  the  bladder.  The  umbilical  ligaments  are  the  fibrous  cords  which 
result  from  the  obliteration  of  the  umbilical  arteries  of  the  foetus ;  they  pass 
forwards  on  each  side  of  the  fundus  of  the  bladder,  and  ascend  beneath 
the  peritoneum  to  the  umbilicus.  The  urachus  is  a  small  fibrous  cord 
formed  by  the  obliteration  of  a  tubular  canal  existing  in  the  embryo :  it  is 
attached  to  the  apex  of  the  bladder,  and  thence  ascends  to  the  umbilicus. 
The  false  ligaments  are  folds  of  peritoneum ;  the  two  lateral  correspond 
with  the  passage  of  the  vasa  deferentia  from  the  sides  of  the  bladder  to 
the  internal  abdominal  rings,  and  the  two  posterior  with  the  course  of  the 
umuilical  arteries,  to  the  fundus  of  the  organ. 

The  bladder  is  composed  of  three  coats,  an  external  or  serous  coat,  a 
muscular,  and  a  mucous  coat.  The  serous  coat  is  partial,  and  derived 
from  the  peritoneum,  which  invests  the  posterior  surface  and  sides  of  the 
bladder,  from  about  opposite  the  point  of  termination  of  th<j  two  ureters 


URINARY    BLADDER. 


533 


to  its  summit,  whence  it  is  guided  to  the  anterior  wall  of  the  abdomen  by 
the  umbilical  ligaments  and  urachus.     The  muscular  coat  consists  of  two 


Fig.  234.' 


layers,  an  external  layer  composed  of  longitudinal  fibres,  the  detrusor 
urinse ;  and  an  internal  layer  of  oblique  and  transverse  fibres  irregularly 
distributed.  The  anterior  longitudinal  fibres  commence  by  four  tendons 
(the  tendons  of  the  bladder  or  of  the  detrusor  urinse),  two  superior  from 
the  ossa  pubis,  and  two  inferior  from  the  rami  of  the  ischia,  and  spread 
out  as  they  ascend  upon  the  anterior  surface  of  the  bladder  to  its  fundus ; 
they  then  converge  upon  the  posterior  surface  of  the  organ,  and  descend 
to  its  neck,  where  they  are  inserted  into  the  isthmus  of  the  prostate  gland, 
and  into  a  ring  of  muscular  tissue,  which  surrounds  the  commencement 
of  the  prostatic  portion  of  the  urethra.  Some  of  the  anterior  fibres  are 
also  attached  to  this  ring.  The  lateral  fibres  commence  at  the  prostate 
gland  and  the  muscular  ring  of  the  urethra  on  one  side,  and  spread  out  as 
they  ascend  upon  the  side  of  the  bladder  to  descend  upon  the  opposite 
side,  and  be  inserted  into  the  prostate  and  opposite  segment  of  the  same 
ring.  Two  bands  of  oblique  fibres  are  described  by  Sir  Charles  Bell,  as 

*A  side  view  of  the  viscera  of  the  male  pelvis,  in  situ.  The  right  side  of  the  pelvis 
has  been  removed  by  a  vertical  section  made  through  the  os  pubis  near  the  symphysis  ; 
and  another  through  the  middle  of  the  sacrum.  1.  The  divided  surface  of  the  os  pubis. 
2.  The  divided  surface  of  the  sacrum.  3.  The  body  of  the  bladder.  4.  Its  fundus;  from 
the  apex  is  seen  passing  upwards  the  urachus.  5.  The  base  of  the  bladder.  6.  The 
ureter.  7.  The  neck  of  the  bladder.  8,  8.  The  pelvic  fascia;  the  fibres  immediately 
above  7  are  given  off  from  the  pelvic  fascia,  and  represent  the  anterior  ligaments  of  the 
bladder.  9.  The  prostate  gland.  10.  The  membranous  portion  of  the  urethra,  between 
the  two  layers  of  the  deep  perineal  fascia.  11.  The  deep  perinea!  fascia  formed  of  two 
layers.  12.  One  of  Cowper's  glands  between  the  two  layers  of  deep  perineal  fascia,  and 
beneath  the  membranous  portion  of  the  urethra.  13.  The  bulb  of  the  corpus  spongiosum. 
14.  The  body  of  the  corpus  spongiosum.  15.  The  right  crus  penis.  16.  The  upper  part 
of  the  first  portion  of  the  rectum.  17.  The  recto-vesical  fold  of  peritoneum.  18.  The 
second  portion  of  the  rectum.  19.  The  right  vesicnla  seminalis.  20.  The  vas  deferens 
21.  The  rectum  covered  by  the  descending  layer  of  the  pelvic  fascia,  just  as  it  is  making 
its  bend  backwards  to  constitute  the  third  portion.  22.  A  part  of  the  levator  ani  muscle 
investing  the  lower  part  of  the  rectum.  23.  The  external  sphincter  ani.  24.  The  in- 
terval between  the  deep  and  superficial  perineal  fascia :  they  are  seen  to  be  continuon* 
beneath  the  number. 

45* 


534  ,     PROSTATE    GLAND. 

originating  at  the  terminations  of  the  ureters,  and  converging  to  the  neck 
of  the  bladder  :  the  existence  of  these  muscles  is  not  well  established 
The  fibres  corresponding  with  the  trigonum  vesieas  are  transverse. 

It  has  been  shown  by  Mr.  Guthrie,*  that  there  are  no  fibres  at  the  neck 
of  the  bladder  capable  of  forming  a  sphincter  vesica  ;  but  Mr.  Lanef  has 
described  a  fasciculus  of  muscular  fibres  which  surround  the  commence- 
ment of  the  urethra,  and  perform  such  an  office.  These  fibres  form  a 
narrow  bundle  above  the  urethra,  but  spread  out  below  behind  the  prostate 
gland  :  they  are  brought  into  view  by  dissecting  off  the  mucous  mem- 
brane from  around  the  orifice  of  the  urethra. 

Sir  Astley  Cooper  has  described  around  the  urethra,  within  the  prostate 
gland,  a  ring  of  elastic  tissue,  or,  rather,  according  to  Mr.  Lane,  of  mus- 
cular fibres,  which  has  for  its  object  the  closure  of  the  urethra  against  the 
involuntary  passage  of  the  urine.  It  is  into  this  ring  that  the  longitudinal 
fibres  of  the  detrusor  urinse  are  inserted,  so  that'the  muscle,  taking  a  fixed 
point  at  the  os  pubis,  will  not  only  compress  the  bladder,  and  thereby 
tend  to  force  its  contents  along  the  urethra,  but  will  at  the  same  time,  by 
means  of  its  attachment  to  the  ring,  dilate  the  entrance  of  the  urethra,  and 
afford  a  free  egress  to  the  contents  of  the  bladder. 

The  Mucous  coat  is  thin  and  smooth,  and  exactly  moulded  upon  the 
muscular  coat,  to  which  it  is  connected  by  a  somewhat  thick  layer  of  sub- 
mucous  tissue,  called  by  some  anatomists  the  nervous  coat  ;  its  papillae 
are  very  minute,  and  there  is  scarcely  a  trace  of  mucous  follicles.  This 
mucous  membrane  is  continuous,  through  the  ureters,  with  the  lining 
membrane  of  the  uriniferous  ducts,  and,  through  the  urethra,  with  that  of 
the  prostatic  ducts,  tubuli  seminiferi,  and  Cowper's  glands. 

Upon  the  internal  surface  of  the  base  of  the  bladder  is  a  triangular 
smooth  plane  of  a  paler  colour  than  the  rest  of  the  mucous  membrane,  the 
trigonum  vesicse,  or  trigone  vesicale,  (fig.  237.)  This  is  the  most  sensi- 
tive part  of  the  bladder,  and  the  pressure  of  calculi  upon  it  gives  rise  to 
great  suffering.  It  is  bounded  on  each  side  by  the  raised  ridge,  corre- 
sponding with  the  muscles  of  the  ureters,  at  each  posterior  angle  by  the 
openings  of  the  ureters,  and,  in  front,  by  a  slight  elevation  of  the  mucous 
membrane  at  the  entrance  of  the  urethra,  called  uvula  vesicce, 

The  external  surface  of  the  base  of  the  bladder  corresponding  with  the 
trigonum,  is  also  triangular,  and  is  separated  from  the  rectum  merely  by  a 
thin  layer  of  fibrous  membrane,  the  recto-vesical  fascia.  It  is  bounded 
behind  by  the  recto-vesical  fold  of  peritoneum  ;  and  on  each  side  by  the 
vas  deferens  and  vesicula  seminalis,  which  converge  almost  to  a  point  at 
the  base  of  the  prostate  gland.  It  is  through  this  space  that  the  opening 
is  made  in  the  recto-vesical  operation  for  puncture  of  the  bladder. 

PROSTATE    GLAND. 


The  prostate  gland  (rgolffTwi  prseponere)  is  situated  in  front  of  the  neck 
of  the  bladder,  behind  the  deep  perineal  fascia,  and  upon  the  rectum, 
through  which  latter  it  may  be  felt  with  the  finger.  It  surrounds  the  com- 
mencement of  the  urethra  for  a  little  more  than  an  inch  of  its  extent,  and 
resembles  a  Spanish  chestnut  both  in  size  and  form  ;  the  base  being 
directed  backwards  towards  the  neck  of  the  bladder,  the  apex  forwards, 

*  "  On  the  Anatomy  and  Diseases  of  the  Neck  of  the  Bladder  and  of  the  Urethra." 
f  Lancet,  vo'.  i.  1842-43,  p.  670. 


VESICULA    SEMINALES. 


535 


and  the  convex  side  towards  the  rectum.  It  is  retained  firmly  in  its  posi- 
tion by  the  two  superior  and  two  inferior  tendons  of  the  bladder,  by  the 
attachments  of  the  pelvic  fascia,  and  by  a  process  of  the  internal  layer  of 
the  deep  perineal  fascia,  which  forms  a  sheath  around  the  membranous 
urethra,  and  is  inserted  into  the  apex  of  the  gland.  It  consists  of  three 
lobes,  two  lateral  and  a  middle  lobe  or  isthmus ;  the  lateral  lobes  are 
distinguished  by  an  indentation  upon  the  base  of  the  gland,  and  by  a  slight 
furrow  upon  its  upper  and  lower  surface.  The  third  lobe  or  isthmus  is  a 
small  transverse  band  which  passes  between  the  two  lateral  lobes  at  the 
base  of  the  organ.  In  structure  the  prostate  gland  is  composed  of  ramified 
ducts,  terminating  in  lobules  of  follicular  pouches,  which  are  so  closely 
compressed  as  to  give  to  a  thin  section  of  the  gland  a  cellular  appearance. 
It  is  pale  in  colour  and  hard  in  texture,  splits  easily  in  the  course  of  its 
ducts,  and  is  surrounded  by  a  plexus  of  veins  which  are  enclosed  by  the 
strong  fibrous  membrane  with  which  it  is  invested.  Its  secretion  is  poured 
into  the  prostatic  portion  of  the  urethra  by  fifteen  or  twenty  excretory 
ducts.  The  urethra  in  passing  through  the  prostate  lies  one-third  nearer 
its  upper  than  its  lower  surface. 

VESICUL.U     SEMINALES. 

On  the  under  surface  of  the  base  of  the  bladder,  and  converging  towards 
the  base  of  the  prostate  gland,  are  two  lobulated  and  somewhat  pyriform 
bodies,  about  two  inches  in  length,  the  vesiculffi  seminales.  Their  upper 
surface  is  in  contact  with  the  base  of  the  bladder ;  the  under  side  rests  on 
the  rectum,  separated  only  by  the  recto-vesical 
fascia ;  the  larger  extremities  are  directed  back- 
wards and  outwards,  and  the  smaller  ends  almost 
meet  at  the  base  of  the  prostate.  They  enclose 
between  them  a  triangular  space,  which  is 
bounded  posteriorly  by  the  recto-vesical  fold  of 
peritoneum,  and  which  corresponds  with  the 
trigonum  vesicae  on  the  interior  of  the  bladder. 
Each  vesicula  is  formed  by  the  convolutions  of 
a  single  tube,  which  gives  off  several  irregular 
csecal  branches.  It  is  enclosed  in  a  dense 
fibrous  membrane,  derived  from  the  pelvic 
fascia,  and  is  constricted  beneath  the  isthmus 
of  the  prostate  gland  into  a  small  excretory 
duct.  The  vas  deferens,  somewhat  enlarged 
and  convoluted,  lies  along  the  inner  border  of 
each  vesicula,  and  is  included  in  its  fibrous  in- 
vestment. It  communicates  with  the  duct  of  the  vesicula,  beneath  the 
isthmus  of  the  prostate,  and  formsf  the  ejaculatory  duct.  The  ejacula- 

•  The  posterior  aspect  of  the  male  bladder ;  the  serous  covering  is  removed  in  order 
to  show  the  muscular  coat.  1.  The  body  of  the  bladder.  2.  Its  fundus.  3.  Its  inferior 
fundus  or  base.  4.  The  urachus.  5,  5.  The  ureters.  6,  6.  The  vasa  deferentia.  7,  7 
The  vesicula?  seminales.  The  triangular  area,  bounded  by  the  vasa  deferentla  ami 
vesiculfE  seminales  on  either  side,  a  dotted  line  above  and  the  numeral  3  below,  is  the. 
space  corresponding  with  the  trigonum  vesicae.  It  is  this  part  of  the  bladder  which  is 
pierced,  in  puncturicg  the  bladder  through  the  rectum.  The  dotted  line,  forming  the 
base  of  this  triangulai  area,  marks  the  extent  of  the  recto-vesical  fold  of  the  peritoneum 

f  It  has  been  customary  hitherto,  in  works  on  anatomy,  to  describe  the  course  of  ox- 
cretory  ducts  as  proceeding  from  the  gland,  and  passing  thence  to  the  point  at  which 


Fig.  235.* 


536  MALE    ORGANS    OF    GENERATION PENIS. 

tory  duel  is  about  three  quarters  of  an  inch  in  length,  and  running  for 
wards,  first  between  the  base  of  the  prostate  and  the  isthmus,  and  then 
through  the  tissue  of  the  veru  montanum,  opens  upon  the  mucous  mem 
brane  of  the  urethra,  near  its  fellow  of  the  opposite  side,  at  the  anterior 
extremity  of  that  process. 

MALE    ORGANS    OF    GENERATION. 

The  organs  of  generation  in  the  male  are,  the  penis  and  the  testes,  with 
their  appendages. 

PENIS. 

The  Penis  is  divisible  into  a  body,  root,  and  extremity.  The  body  is 
surrounded  by  a  thin  integument,  which  is  remarkable  for  the  looseness 
of  its  areolar  connexion  with  the  deeper  parts  of  the  organ,  and  for  con- 
taining no  adipose  tissue.  The  root  is  broad,  and  firmly  adherent  to  the 
rami  of  the  ossa  pubis  and  ischia  by  means  of  two  strong  processes,  the 
crura,  and  is  connected  to  the  symphysis  pubis  by  a  fibrous  membrane,  the 
ligamentum  suspensorium.  The  extremity,  or  glans  penis,  resembles  an 
obtuse  cone,  somewhat  compressed  from  above  downwards,  and  of  a 
deeper  red  colour  than  the  surrounding  skin.  At  its  apex  is  a  small  ver- 
tical slit,  the  meatus  urinarius,  which  is  bounded  by  two,  more  or  less 
protuberant,  labia;  and,  extending  backwards  from  the  meatus,  is  a  de- 
pressed raphe,  to  which  is  attached  a  loose  fold  of  mucous  membrane,  the 
frsenum  praeputii.  The  base  of  the  glans  is  marked  by  a  projecting  collar, 
the  corona  glandis,  upon  which  are  seen  a  number  of  small  papillary  ele- 
vations, the  glandulee  Tysoni  (odoriferEe).  Behind  the  corona  is  a  deep 
fossa,  bounded  by  a  circular  fold  of  integument,  the  preeputium,  which,  in 
the  quiescent  state  of  the  organ,  may  be  drawn  over  the  glans,  but,  in  its 
distended  state,  is  obliterated,  and  serves  to  facilitate  its  enlargement.  The 
internal  surface  of  the  prepuce  is  lined  by  mucous  membrane,  covered  by 
a  thin  epithelium  ;  this  membrane,  on  reaching  the  base  of  the  glans,  is 
reflected  over  the  glans  penis,  and,  at  the  meatus  urinarius,  is  continuous 
with  the  mucous  lining  of  the  urethra. 

The  penis  is  composed  of  the  corpus  cavernosum  and  corpus  spongio- 
sum,  and  contains  in  its  interior  the  longest  portion  of  the  urethra. 

The  Corpus  cavernosum  is  distinguished  into  two  lateral  portions  (cor- 
pora cavernosa)  by  an  imperfect  septum  and  by  a  superior  and  inferior 
groove,  and  is  divided  posteriorly  into  two  crura.  It  is  firmly  adherent, 
by  means  of  its  crura,  to  the  rami  of  the  ossa  pubis  and  ischia.  It  forms, 
anteriorly,  a  single  rounded  extremity,  which  is  received  into  a  fossa  in 
the  base  of  the  glans  penis ;  the  superior  groove  lodges  the  dorsal  vessels 
of  the  organ,  and  the  inferior  receives  the  corpus  spongiosum.  Its  fibrous 
tunic  is  thick,  elastic,  and  extremely  firm,  and  sends  a  number  of  fibrous 
bands  and  cords  (trabeculte)  inwards  from  its  inferior  groove,  which  cross 
its  interior  in  a  radiating  direction,  and  are  inserted  into  the  inner  walls  of 
the  tunic.  These  trabeculse  are  most  abundant  on  the  middle  line,  where 

the  secretion  is  poured  out.  In  the  description  of  the  vas  deferens,  with  its  connexion 
with  the  duct  (if  the  vesicula  seminalis,  I  have  adopted  this  pl°n,  that  I  might  not  too 
far  depart  from  established  habit.  But  as  it  is  more  correct  and  consistent  with  the 
present  state  of  science  to  consider  the  gland  as  a  development  of  the  duct,  I  have  pur- 
sued the  lat'er  principle  in  the  description  of  most  of  the  other  glandular  organs  of  the 


ERECTILE    TISSUE URETHRA.  537 

tney  are  ranged  vertically,  side  by  side,  somewhat  like  the  teeth  of  a  comb, 
and  constitute  the  imperfect  partition  of  the  corpus  cavernosum,  called 
septum  pediniforme.  This  septum  is  more  complete  at  its  posterior  than 
towards  its  anterior  part. 

The  tunic  of  the  corpus  cavernosum  consists  of  strong  longitudinal  fibrous 
fasciculi,  closely  interwoven  with  each  other.  Its  internal  structure  is 
composed  of  erectile  tissue. 

The  Corpus  spongiosum  is  situated  along  the  under  surface  of  the  corpus 
cavernosum,  in  its  inferior  groove.  It  commences  by  its  posterior  extre- 
mity between  and  beneath  the  crura  penis,  where  it  forms  a  considerable 
enlargement,  the  bulb,  and  terminates  anteriorly  by  another  expansion,  the 
glans  penis.  Its  middle  portion,  or  body,  is  nearly  cylindrical,  and  tapers 
gradually  from  its  posterior  towards  its  anterior  extremity.  The  bulb  is 
adherent  to  the  deep  perineal  fascia  by  means  of  the  tubular  prolongation 
of  the  anterior  layer,  which  surrounds  the  membranous  portion  of  the 
urethra ;  in  the  rest  of  its  extent  the  corpus  spongiosum  is  attached  to  the 
corpus  cavernosum  by  areolar  tissue,  and  by  veins  which  wind  around 
that  body  to  reach  the  dorsal  vein.  It  is  composed  of  erectile  tissue,  en- 
closed by  a  dense  fibrous  layer,  much  thinner  than  that  of  the  corpus 
cavernosum,  and  contains  in  its  interior  the  spongy  portion  of  the  urethra, 
\vhich  lies  nearer  its  upper  than  its  lower  wall. 

Erectile  tissue  is  a  peculiar  cellulo-vascular  structure,  entering  in  con- 
siderable proportion  into  the  composition  of  the  organs  of  generation.  It 
consists  essentially  of  a  plexus  of  veins  so  closely  convoluted  and  inter- 
woven  with  each  other,  as  to  give  rise  to  a  cellular  appearance  when  ex- 
amined by  means  of  a  section.  The  veins  forming  this  plexus  are  smaller 
in  the  glans  penis,  corpus  spongiosum,  and  circumference  of  the  corpus 
cavernosum,  than  in  the  central  part  of  the  latter,  where  they  are  large  and 
dilated.  They  have  no  other  coat  than  the  internal  lining  prolonged  from 
the  neighbouring  veins  ;  and  the  interstices  of  the  plexus  are  occupied  by 
a  peculiar  reddish  fibrous  tissue.  They  receive  their  blood  from  the  ca- 
pillaries of  the  arteries  in  the  same  manner  with  veins  generaljy,  and  not 
by  means  of  vessels  having  a  peculiar  form  and  distribution,  as  described 
by  Miiller.  The  helicine  arteries  of  that  physiologist  have  no  existence. 

Vessels  and  Nerves. — The  arteries  of  the  penis  are  derived  from  the  in- 
ternal pudic ;  they  are,  the  arteries  of  the  bulb,  arteries  of  the  corpus 
cavernosum,  and  dorsales  penis.  Its  veins  are  superficial  and  deep.  The 
deep  veins  run  by  the  side  of  the  deep  arteries,  and  terminate  in  the  in- 
ternal pudic  veins.  The  superficial  veins  escape  in  considerable  number 
from  the  base  of  the  glans,  and  converge  on  the  dorsuin  penis,  to  form  a 
large  dorsal  vein,  which  receives  other  veins  from  the  corpus  cavernosum 
and  spongiosum  in  its  course,  and  passes  backwards  between  two  layers 
of  the  ligamentum  suspensorium,  and  through  the  deep  fascia  beneath  the 
arch  of  the  os  pubis,  to  terminate  in  the  prostatic  and  vesical  plexuses. 

The  Lymphatics  terminate  in  the  inguinal  glands.  The  Nerves  are  de- 
rived from  the  internal  pudic  nerve,  from  the  sacral  plexus,  and,  as  shown 
by  Professor  Muller,  in  his  beautiful  monograph,  from  the  hypogastrie 
plexus. 

URETHRA. 

The  urethra  is  the  membranous  canal  extending  from  the  neck  of  the 
bladder  to  the  meatus  urinarius.  It  is  curved  in  its  course,  and  is  com- 


538 


URETHRA. 


posed  of  two  layers,  a  mucous  coat  and  an  elastic  fibrous  coat.     The  mu 
cous  coat  is  thin  and  smooth ;  it  is  continuous,  internally,  with  the  mucous 
membrane  of  the  bladder  ;  externally,  with  the  investing  membrane  of  the 
glans  ;  and  at  certain  points  of  its  extent,  with  the  lining  membrane  of  the 
numerous  ducts  which  open  into  the  urethra,  namely,  those  of  Cowper's 


Fig.  236  * 


glands,  the  prostate  gland,  vasa  deferentia,  and  vesicula?  seminales.  The 
elastic  fibrous  coat  varies  in  thickness  in  the  different  parts  of  the  course 
of  the  urethra:  it  is  thick  in  the  prostate  gland,  forms  a  firm  investment 
for  the  membranous  portion  of  the  canal,  and  is  thin  in  the  spongy  porflon, 
where  it  serves  as  a  bond  of  connexion  between  the  mucous  membrane 
and  the  corpus  spongiosum.  The  urethra  is  about  nine  inches  in  length, 
and  is  divided  into  a  prostatic,  membranous,  and  spongy  portion. 

The  Prostatic  portion,  a  little  more  than  an  inch  in  length,  is  situated 
in  the  prostate  gland,  about  one-third  nearer  its  upper  than  its  lower 
surface,  and  extending  from  its  base  to  its  apex.  Upon  its  lower  circuin- 

*  A  longitudinal  section  of  the  bladder,  prostate  gland,  and  penis,  showing  the  urethra. 
1.  The  urachus  attached  to  the  upper  part  of  the  fund  us  of  the  bladder.  2.  The  recto- 
vesical  fold  of  peritoneum,  at  its  point  of  reflexion  from  the  base  of  the  bladder,  upon 
the  anterior  surface  of  the  rectum.  3.  The  opening  of  the  right  ureter.  4.  A  slight 
ridge,  formed  by  the  muscle  of  the  ureter,  and  extending  from  the  termination  of  the 
ureter  to  the  commencement  of  the  urethra.  This  ridge  forms  the  lateral  boundary  of 
the  trigonum  vesicse.  5.  The  commencement  of  the  urethra;  the  elevation  of  mucous 
membrane  immediately  below  the  number  is  the  uvula  vesicce.  The  constriction  of  the 


bladder  at  this  point  is  the  i 
7.  The  prostate  gland  ;   the 
urethra,  is  shown.     8.  The 
which  the  ejaculatory  duct 
deferens  is  seen  to  be  cut  si 


eck  of  the  bladder.  6.  The  prostatic  portion  of  the  urethra, 
lifference  of  thickness  of  the  gland,  above  and  below  the 
sthmus,  or  third  lobe  of  the  prostate;  immediately  beneath 
s  seen  passing.  9.  The  right  vesicula  serninalis  ;  the  vas 
ort  off,  close  to  its  junction  with  the  ejaculatory  duct.  10. 


The  membranous  portion  of  the  urethra.  11.  Cowper's  gland  of  the  ri^ht  side,  with  jt.s 
duct.  12.  The  bulbous  portion  of  the  urethra;  throughout  the  whole  length  of  the  ure- 
thra of  the  corpus  spongiosum,  numerous  lacuna?  are  seen.  13.  The  fossa  navicularis. 
14.  The  corpus  cavernosum,  cut  somewhat  obliquely  to  the  right  side,  near  its  lower 
part.  The  character  of  the  venous  cellular  texture  is  well  shown.  15.  The  right  cms 
penis.  16.  Near  the  upper  part  of  the  corpus  cavernosum,  the  section  has  fallen  a  little 
to  the  left  of  the  middle  line. ;  a  portion  of  the  septum  pectiniforme  is  consequently 
seen.  This  figure  also  indicates  the  thickness  of  the  fibrous  investment  of  the  corpus 
cavernosum,  and  its  abrupt  termination  at  the  base  of  (17)  the  glans  penis.  8.  The 
•ower  segment  of  the  glans.  19.  The  meatus  urinarius.  20.  The  corpus  spongiosum 
VI.  The  bulb  of  the  corpus  spongiosum. 


URETHRA. 


539 


Fig.  237» 


terence  or  floor  is  a  longitudinal  fold  of  mucous 
membrane,  the  veru  montanum,  or  caput  o-allina- 
gmis,  and  on  each  side  of  the  veru,  a  depressed  ' 
fossa,  the  prostatic  sinus,  in  which  are  seen  the 
numerous  openings  of  the  prostatic  ducts.  At  the 
anterior  extremity  of  the  veru  montanum  are  the 
openings  of  the  two  ejaculatory  ducts,  and  between 
them  a  third  opening,  which  leads  backwards  into 
a  small  caecal  sac,  the  sinus  pocularis.  The  pros- 
tatic portion  of  the  urethra,  when  distended,  is  the 
most  dilated  part  of  the  canal ;  but,  excepting  dur- 
ing the  passage  of  urine,  is  completely  closed  by 
means  of  a  ring  of  muscular  tissue  which  encircles 
the  urethra  as  far  as  the  anterior  extremity  of  the 
veru  montanum.  In  the  contracted  state  of  the 
urethra,  the  veru  montanum  acts  as  a  valve,  being 
pressed  upwards  against  the  upper  wall  of  the 
canal ;  but,  during  the  action  of  the  detrusor  mus- 
cle of  the  bladder,  the  whole  ring  is  expanded  by 
the  longitudinal  muscular  fibres  which  are  inserted 
into  it ;  and  the  veru  is  especially  drawn  down  by  two  delicate  tendons, 
which  have  been  traced  by  Mr.  Tyrrell  from  the  posterior  fibres  of  the 
detrusor  into  the  tissue  of  this  process. 

The  Membranous  portion,  the  narrowest  part  of  the  canal,  is  somewhat 
less  than  an  inch  in  length.  It  is  situated  between  the  two  layers  of  the 
deep  perineal  fascia,  and  is  surrounded  by  the  fan-like  expansions  of  the 
upper  and  lower  segments  of  the  compressor  urethrse  muscle,  which  meet 
at  the  raphe  along  its  upper  and  lower  surface.  It  is  continuous  posteriorly 
with  the  prostatic  urethra,  and  anteriorly  with  the  spongy  portion  of  the 
canal.  Its  coverings  are,  the  mucous  membrane,  elastic  fibrous  layer, 
compressor  urethrse  muscle,  and  a  partial  sheath  from  the  deep  perineal 
fascia. 

The  Spongy  portion  forms  the  rest  of  the  extent  of  the  canal,  and  is 
lodged  in  the  corpus  spongiosum  from  its  commencement  at  the  deep 
perineal  fascia  to  the  meatus  urinarius.  It  is  narrowest  in  the-  body,  and 
becomes  dilated  at  either  extremity,  posteriorly  in  the  bulb,  where  it  is 
named  the  bulbous  portion,  and  anteriorly  in  the  glans  penis,  where  it 
forms  the  fossa  navicularis.  The  meatus  urinarius  is  the  most  constricted 
part  of  the  canal ;  so  that  a  catheter,  which  will  enter  that  opening,  may 
be  passed  freely  through  the  whole  extent  of  a  normal  urethra.  Opening 
into  the  bulbous  portion  are  two  small  excretory  ducts  about  three-quar- 
ters of  an  inch  in  length,  which  may  be  traced  backwards,  between  the 
coats  of  the  urethra  and  jjie  bulb,  to  the  interval  between  the  two  layers 

*  The  bulbous,  membranous,  and  prostatic  urethra,  with  part  of  the  bladder.  1.  Part 
of  the  urinary  bladder;  its  internal  surface.  2.  The  trigonum  vesicae.  3.  The  openings 
of  the  ureters.  4.  The  uvula  vesicae.  5.  The  veru  montanum.  6.  The  opening  of  the 
sinus  pocularis.  7,  7.  The  apertures  of  the  ejaculatory  ducts.  8,  8.  The  openings  of 
the  prostatic  ducts.  The  numbers  7,  7,  and  8,  8,  are  placed  on  the  cut  surface  of  th« 
supra-urethral  portion  of  the  prostate  gland.  9,  9.  The  lateral  lobes  of  the  prostate  gland. 
a.  The  membranous  portion  of  the  urethra,  b,  b.  Cowper's  glands,  c,  c.  The  apertures 
of  the  excretory  ducts  of  Cowper's  glands,  d.  The  commencement  of  the  bulbous  por- 
tion of  the  urethra,  e,  e.  The  upper  surface  of  the  bulb  of  the  corpus  spongiosum.  /.  / 
The  crura  penis,  g,  g.  The  corpus  cavernosurn.  h.  The  spongy  portion  of  the  urethra 


540  SCROTUM SPERMATIC  CORD. 

of  the  deep  perineal  fascia,  where  they  ramify  in  two  small  tabulated  and 
somewhat  compressed  glands,  of  about  the  size  of  peas.  These  are  Cow- 
per's  glands ;  they  are  situated  immediately  beneath  the  membranous  por 
tion  of  the  urethra,  and  are  enclosed  by  the  lower  segment  of  the  com- 
pressor urethras  muscle,  so  as  to  be  subject  to  muscular  compression. 
Upon  the  whole  of  the  internal  surface  of  the  spongy  portion  of  the  urethra, 
particularly  along  its  upper  wall,  are  numerous  small  openings  or  lacunae, 
which  are  the  apertures  of  mucous  glands  situated  in  the  submucous  areo- 
lar  tissue.  The  openings  of  these  lacuna?  are  directed  forwards,  and  are 
liable  occasionally  to  intercept  the  point  of  a  small  catheter  in  its  passage 
into  the  bladder.  At  about  an  inch  and  a  half  from  the  opening  of  the 
meatus,  one  of  these  lacunae  is  generally  found  much  larger  than  the  rest, 
and  is  named  the  lacuna  magna.  In  a  preparation  of  this  lacuna,  made 
by  Sir  Astley  Cooper,  the  extremity  of  the  canal  presents  several  large 
primary  ramifications. 

TESTES. 

The  testes  are  two  small  glandular  organs  suspended  from  the  abdomen 
by  the  spermatic  cords,  and  enclosed  in  an  external  tegumentary  covering, 
the  scrotum. 

The  SCROTUM  is  distinguished  into  two  lateral  halves  or  hemispheres 
by  a  raphe,  which  is  continued  anteriorly  along  the  under  surface  of  the 
penis,  and  posteriorly  along  the  middle  line  of  the  perineum  to  the  anus. 
Of  these  two  lateral  portions  the  left  is  somewhat  longer  than  the  right, 
and  corresponds  with  the  greater  length  of  the  spermatic  cord  on  the  left 
side. 

The  scrotum  is  composed  of  two  layers,  the  integument  and  a  proper 
covering,  the  dartos ;  the  integument  is  extremely  thin,  transparent,  and 
abundant,  and  beset  by  a  number  of  hairs  which  issue  obliquely  from  the 
skin,  and  have  prominent  roots.  The  dartos  is  a  thin  layer  of  contractile 
fibrous  tissue,  intermediate  in  properties  between  muscular  fibre  and  elastic 
tissue ;  it  forms  the  proper  tunic  of  the  scrotum,  and  sends  inwards  a  dis- 
tinct septum  (septum  scroti),  which  divides  it  into  two  cavities  for  the  two 
testes.  The  dartos  is  continuous  around  the  base  of  the  scrotum  with  the 
common  superficial  fascia  of  the  abdomen  and  perineum. 

The  SPERMATIC  CORD  is  the  medium  of  communication  between  the 
testes  and  the  interior  of  the  abdomen ;  it  is  composed  of  arteries,  veins, 
lymphatics,  nerves,  the  excretory  duct  of  the  testicle,  and  investing  tunics. 
It  commences  at  the  internal  abdominal  ring,  where  the  vessels  of  which 
it  is  composed  converge,  and  passes  obliquely  along  the  spermatic  canal ; 
the  cord  then  escapes  at  the  external  abdominal  ring,  and  descends  through 
the  scrotum  to  the  posterior  border  of  the  testicle.  The  left  cord  is  some- 
what longer  than  the  right,  and  permits  the  left  testicle  to  reach  a  lower 
level  than  its  fellow. 

The  Arteries  of  the  spermatic  cord  are,  the  spermatic  artery  from  the 
aorta;  the  deferential  artery,  accompanying  the  vas  deferens,  from  the 
superior  vesical ;  and  the  cremasteric  branch  from  the  epigastric  artery. 
The  spermatic  veins  form  a  plexus,  which  constitutes  the  chief  bulk  of  the 
cord ,  they  are  provided  with  valves  at  short  intervals,  and  the  smaller 
veins  have  a  peculiar  tendril-like  arrangement  which  has  obtained  for  them 
me  name  of  vasa  pampiniformia.  The  lymphatics  are  of  large  size,  and 
terminate  in  the  lumbar  glands.  The  nerves  are  the  spermatic  plexus, 


TESTES EPIDIDYMIS.  541 

which  is  derived  from  the  aortic  and  renal  plexus,  the  genitai  branch  of 
the  genito-crural  nerve,  and  the  scrotal  branch  of  the  ilio-scrotal. 

The  Vas  deferens,  the  excretory  duct  of  the  testicle,  is  situated  along 
the  posterior  border  of  the  cord,  where  it  may  easily  be  distinguished  by 
the  hard  and  cordy  sensation  which  it  communicates  to  the  fingers.  Its 
parietes  are  very  thick  and  tou^h,  and  its  canal  extremely  small,  and  lined 
by  the  mucous  membrane  continued  from  the  urethra. 

The  Coverings  of  the  spermatic  cord  are,  the  spermatic  fascia,  cremaster 
muscle,  and  fascia  propria.  The  spermatic  fascia  is  a  prolongation  of  the 
intercolumnar  fascia,  derived  from  the  borders  of  the  external  abdominal 
ring  during  the  descent  of  the  testicle  in  the  foetus.  The  cremasteric  co- 
vering (erythroid)  is  the  thin  muscular  expansion  formed  by  the  spreading 
out  of  the  fibres  of  the  cremaster,  which  is  likewise  carried  down  by  the 
testis  during  its  descent.  The  fascia  propria  is  a  continuation  of  the 
infundibuliform  process  from  the  transversalis  fascia,  which  immediately 
invests  the  vessels  of  the  cord,  and  is  also  obtained  during  the  descent  of 
the  testis. 

TESTES. 

The  TESTIS  (testicle)  is  a  small  oblong  and  rounded  gland,  somewhat 
compressed  upon  the  sides  and  behind,  and  suspended  in  the  cavity  of  the 
scrotum  by  the  spermatic  cord. 

Its  position  in  the  scrotum  is  oblique ;  so  that  the  upper  extremity  is 
directed  upwards  and  forwards,  and  a  little  out- 
wards; the  lower,  downwards  and  backwards,  and 
a  little  inwards ;  the  convex  border  looks  forwards 
and  downwards,  and  the  flattened  border,  to  which 
the  cord  is  attached,  backwards  and  upwards.  Lying 
against  its  outer  and  posterior  body  is  a  flattened 
body  which  follows  the  course  of  the  testicle,  and 
extends  from  its  upper  to  its  lower  extremity ;  this 
body  is  named,  from  its  relation  to  the  testis,  epi- 
didymis  (J#<,  upon,  <5/<Jufjios,  the  testicle) ;  it  is  divided 
into  a  central  part  or  body,  an  upper  extremity  or 
globus  major,  and  a  lower  extremity,  globus  minor 
(cauda)  epididymis.  The  globus  major  is  situated 
against  the  upper  end  of  the  testicle,  to  which  it  is 
closely  adherent ;  the  globus  minor  is  placed  at  its  lower  end,  is  attached 
to  the  testis  by  areolar  tissue,  and  curves  upwards,  to  become  continuous 
with  the  vas  deferens.  The  testis  is  invested  by  three  tunics,  tunica  vagi- 
nalis,  tunica  albuginea,  and  tunica  vasculosa,  and  is  connected  to  the  inner 
surface  of  the  dartos  by  a  large  quantity  of  extremely  loose  areolar  tissue, 

*  A  transverse  section  of  the  testicle.  1.  The  cavity  of  the  tunica  vaginalis;  the  most 
external  layer  is  the  tunica  vaginalis  reflexa ;  and  that  in  contact  with  the  organ,  the 
tunica  vaginalis  propria.  2.  The  tunica  albuginea.  3.  The  mediastinum  testis,  giving 
off  numerous  fibrous  cords  in  a  radiated  direction  to  the  internal  surface  of  the  tunica 
albuginea.  The  cut  extremities  of  the  vessels  below  the  number  belong  to  the  rete 
testis ;  and  those  above,  to  the  arteries  and  veins  of  the  organ.  4.  The  tunica  vascu- 
losa, or  pia  mater  testis.  5.  One  of  the  lobules,  consisting  of  the  convolutions  of  the 
tubuli  seminiferi,  and  terminating  by  a  single  duct,  the  vas  rectum.  Corresponding 
lobules  are  seen  between  the  other  fibrous  cords  of  the  mediastinum.  0.  Section  of  the 
epididymis. 

46 


542  STRUCTURE    OF    THE    TESTIS. 

in  which  fat  is  never  deposited,  but  which  is  very  susceptible  of  serous 
infiltration. 

The  Tunica  vaginalis  is  a  pouch  of  serous  membrane  derived  from  the 
peritoneum  in  the  descent  of  the  testis,  and  afterwards  obliterated  from 
the  abdomen  to  within  a  short  distance  of  the  gland.  Like  other  serous 
coverings,  it  is  a  shut  sac,  investing  the  organ,  and  thence  reflected  so  as 
to  form  a  bag  around  its  circumference :  hence  it  is  divided,  into  the 
tunica  vaginalis  propria^  and  tunica  vaginalis  reflexa.  The  tunica  vagi- 
nalis propria  covers  the  surface  of  the  tunica  albuginea,  and  surrounds  the 
epididymis,  connecting  it  to  the  testis  by  means  of  a  distinct  duplicature. 
The  tunica  vaginalis  reflexa  is  attached  by  its  external  surface,  through 
the  medium  of  a  quantity  of  loose  areolar  tissue,  to  the  inner  surface  of  the 
dartos.  Between  the  two  layers  is  the  smooth  surface  of  the  shut  sac, 
moistened  by  its  proper  secretion. 

The  Tunica  albuginea  (dura  mater  testis)  is  a  thick  fibrous  membrane, 
of  a  bluish  white  colour,  and  the  proper  tunic  of  the  testicle.  It  is  adhe- 
rent externally  to  the  tunica  vaginalis  propria,  and  from  the  union  of  a 
serous  with  a  fibrous  membrane  is  considered  to  be  a  fibro-serous  mem- 
brane, like  the  dura  mater  and  pericardium.  After  surrounding  the  tes- 
ticle, the  tunica  albuginea  is  reflected  from  its  posterior  border  into  the 
interior  of  the  gland,  and  forms  a  projecting  longitudinal  ridge,  which  is 
called  the  mediastinum  testis  (corpus  Highmorianum*),  from  which  nume- 
rous fibrous  cords  (trabeculae,  septula)  are  given  off,  to  be  inserted  into  the 
inner  surface  of  the  tunic.  The  mediastinum  serves  to  contain  the  vessels 
and  ducts  of  the  testicle  in  their  passage  into  the  substance  of  the  organ, 
and  the  fibrous  cords  are  admirably  fitted,  as  has  been  shown  by  Sir  Astley 
Cooper,  to  prevent  compression  of  the  gland.  If  a  transverse  section  be 
made  of  the  testis,  and  the  surface  of  the  mediastinum  examined,  it  will 
be  observed  that  the  blood-vessels  of  the  substance  of  the  organ  are  situated 
near  the  posterior  border  of  the  mediastinum,  while  the  divided  ducts  of 
the  rete  testis  occupy  a  place  nearer  the  free  margin. 

The  Tunica  vasculosa  (pia  mater  testis)  is  the  nutrient  membrane  of  the 
testis  ;  it  is  situated  immediately  within  the  tunica  albuginea,  and  encloses 
the  substance  of  the  gland,  sending  processes  inwards  between  the  lobules, 
in  the  same  manner  that  the  pia  mater  is  reflected  between  the  convolu- 
tions of  the  brain. 

The  substance  of  the  testis  consists  of  numerous  conical  flattened  lobules 
(lobuli  testis),  the  bases  being  directed  towards  the  surface  of  the  organ, 
and  the  apices  towards  the  mediastinum.  Krause  found  between  four  and 
five  hundred  of  these  lobules  in  a  single  testis.  Each  lobule  is  invested 
by  a  distinct  sheath,  formed  of  two'  layers,  one  being  derived  from  the 
tunica  vasculosa,  the  other  from  the  tunica  albuginea.  The  lobule  is  com- 
posed of  one  or  several  minute  tubuli,  tubuli  seminiferi,^  exceedingly  con- 
voluted, anastomosing  frequently  with  each  other  near  their  extremities, 
terminating  in  loops  or  in  free  csecal  ends,  and  of  the  same  diameter  (T^g 

*  Nathaniel  Highmore,  a  physician  of  Oxford,  in  his  "  Corporis  Humani  Disquisitio 
Anatomica,"  published  in  1651,  considers  the  corpus  Highmorianum  as  a  duct  formed 
by  the  convergence  of  the  fibrous  cords,  which  he  mistakes  for  smaller  ducts. 

f  i^auth  estimates  the  whole  number  of  tubuli  seminiferi  in  each  testis  at  840,  and 
their  average  length  at  2  feet  3  inches.  According  to  this  calculation,  the  whole  length 
pf  liie  tubuli  seminiferi  would  be  1890  feet. 


STRUCTURE    OF    THE    EPIDIDYMIS. 


.54.3 


Fig.  239* 


of  an  inch,  Lauth)  throughout.  The  tubuli  seminiferi  are  of  a  bright 
yellow  colour;  they  become  less  convoluted  in  the 
apices  of  the  lobules,  and  terminate  by  formino-  be- 
tween twenty  and  thirty  small  straight  ducts  of  about 
twice  the  diameter  of  the  tubuli  seminiferi,  the  vasa 
recta.  The  vasa  recta  enter  the  substance  of  the 
mediastinum,  and  terminate  in  from  seven  to  thirteen 
ducts,  smaller  in  diameter  than  the  vasa  recta.  These 
ducts  pursue  a  waving  course  from  below  upwards 
through  the  fibrous  tissue  of  the  mediastinum ;  they 
communicate  freely  with  each  other,  and  constitute 
the  rete  testis.  At  the  upper  extremity  of  the  medi- 
astinum, the  ducts  of  the  rete  testis  terminate  in  from 
nine  to  thirty  small  ducts,  the  vasa  efferentia^  which 
form  by  their  convolutions  a  series  of  conical  masses, 
the  com  vasculosi ;  from  the  bases  of  these  cones 
tubes  of  larger  size  proceed,  which  constitute,  by 
their  complex  convolutions,  the  body  of  the  epi- 
didymis.  The  tubes  become  gradually  larger  towards 
the  lower  end  of  the  epididymis,  and  terminate  in  a 
single  large  and  convoluted  duct,  the  vas  deferens. 

The  Epididymis  is  formed  by  the  convolutions  of  the  excretory  seminal 
ducts,  externally  to  the  testis,  and  previously  to  their  termination  in  the 
vas  deferens.  The  more  numerous  convolutions  and  the  aggregation  of 
the  coni  vasculosi  at  the  upper  end  of  the  organ  constitute  the  globus 
major;  the  continuation  of  the  convolutions  downwards  is  the  body;  and 
the  smaller  number  of  convolutions  of  the  single  tube  at  the  lower  extre- 
mity, the  globus  minor.  The  tubuli  are  connected  together  by  a  very 
delicate  areolar  tissue,  and  are  enclosed  by  the  tunica  vaginalis. 

A  small  convoluted  duct,  of  variable  length,  is  generally  connected 
with  the  duct  of  the  epididymis  immediately  before  the  commencement  of 
the  vas  deferens.  This  is  the  vasculum  aberrans  of  Haller ;  it  is  attached 
to  the  epididymis  by  the  areolar  tissue  in  which  that  body  is  enveloped. 
Sometimes  it  becomes  dilated  towards  its  extremity,  but  more  frequently 
retains  the  same  diameter  throughout. 

Ths  Vas  deferens  may  be  traced  upwards  in  the  course  of  the  seminal 
fluid,  from  the  globus  minor  of  the  epididymis  along  the  posterior  part  of 
the  spermatic  cord,  and  along  the  spermatic  canal  to  the  internal  abdomi- 
nal ring.  From  the  ring  it  is  reflected  inwards  to  the  side  of  the  fundus 
of  the  bladder,  and  descends  along  its  posterior  surface,  crossing  the  direc- 
tion of  the  ureter,  to  the  inner  border  of  the  vesicula  seminalis.  In  this 
situation  it  becomes  somewhat  larger  in  size  and  convoluted,  and  termi- 
nates at  the  base  of  the  prostate  gland,  by  uniting  with  the  duct  of  the 
vesicula  seminalis  and  constituting  the  ejaculatory  duct.  The  ejaculatory 

*  Anatomy  of  the  testis.  I,  1.  The  tunica  albuginea.  2,  2.  The  mediastinum  testis. 
3,  3.  The  lobuli  testis.  4,  4.  The  vasa  recta.  5.  The  rete  testis.  6.  The  vasa  elfc- 
rentia,  of  which  six  only  are  represented  in  this  diagram.  7.  The  coni  vasculosi 
constituting  the  globus  major  of  the  epididymis.  8.  The  body  of  the  epididymis 
9.  The  globus  minor  of  the  epididymis.  10.  The  vas  deferens.  11.  The  vasculum 
aberrans.  . 

f  Each  vas  efferens  with  its  cone  measures,  according  to  Lauth,  about  8  inches.  The 
entire  length  of  the  tubes  composing  the  epididymis,  according  r>  the  same  authority,  i> 
about  21  feet. 


544 


FEMALE    PELVIS. 

Fig.  240.* 


duct,  which  is  thus  formed  by  the  junction  of  the  duct  of  the  vesicula 
serainalis  with  the  vas  deferens,  passes  forwards  to  the  anterior  extremity 
of  the  veru  montanum,  where  it  terminates  by  opening  into  the  prostatic 
urethra. 

FEMALE    PELVIS. 

The  peculiarities  in  form  of  the  female  pelvis  have  already  been  ex- 
amined with  the  anatomy  of  the  bones  (p.  118).  Its  lining  boundaries  are 
the  same  with  those  of  the  male.  The  contents  are,  the  bladder,  vagina, 
uterus  with  its  appendages,  and  the  rectum.  Some  portion  of  the  small 
intestines  also  occupies  the  upper  part  of  its  cavity. 

The  Bladder  is  in  relation  with  the  ossa  pubis  in  front,  with  the  uterus 
behind,  from  which  it  is  usually  separated  by  a  convolution  of  small  in- 
testine, and  with  the  neck  of  the  uterus  and  vagina  beneath.  The  form 
of  the  female  bladder  corresponds  with  that  of  the  pelvis,  being  broad 
from  side  to  side,  and  often  bulging  more  on  one  side  than  on  the  other. 
This  is  particularly  evident  after  frequent  parturition.  The  coats  of  the 
bladde:  are  the  same  as  those  of  the  male. 

The  Urethra  is  about  an  inch  and  a  half  in  length,  and  is  lodged  in  ths 
upper  wall  of  the  vagina,  in  its  course  downwards  and  forwards,  beneath 
the  aich  of  the  os  pubis,  to  the  meatus  urinarius.  It  is  lined  by  mucous 
membrane,  which  is  disposed  in  longitudinal  folds,  and  is  continuous  in 
ternally  with  that  of  the  bladder,  and  externally  with  that  of  the  vulva , 
the  mucous  membrane  is  surrounded  by  a  proper  coat  of  elastic  tissue,  to 
which  the  muscular  fibres  of  the  detrusor  urinae  are  attached.  It  is  to  the 
elastic  tissue  that  is  due  the  remarkable  dilatability  of  the  female  urethra, 

*  Human  testis  injected  with  mercury.  1,  1.  Lobules  formed  of  seminiferous  tubes 
2.  Rete  testis  3.  Vasa  efferentia.  4.  Plexuses  of  the  efferent  vessels  passing  into  tha 
head  of  the  epididymis  5,  5.  6.  Body  of  the  epididymis.  7.  Its  appendix;  its  tail  01 
rauda.  8.  Vas  deferens. — (Lauth.') 


FEMALE    PELVIS — VAGINA. 

Fig.  241  * 


545 


and  its  speedy  return  to  its  original  diameter.  The  meatus  is  encircled 
by  a  ring  of  fibrous  tissue,  which  prevents  it  from  distending  with  the 
same  facility  as  the  rest  of  the  canal ;  hence  it  is  sometimes  advantageous 
in  performing  this  operation  to  divide  the  margin  of  the  meatus  slightly 
with  the  knife. 

VAGINA. 

The  Vagina  is  a  membranous  canal,  leading  from  the  vulva  to  the 
uterus,  and  corresponding  in  direction  with  the  axis  of  the  outlet  of  the 
pelvis.  It  is  constricted  at  its  commencement,  but  ne^ir  the  uterus  becomes 
dilated ;  and  is  closed  by  the  contact  of  the  anterior  with  the  posterior 
wall.  Its  length  is  variable ;  but  it  is  always  longer  upon  the  posterior 
than  upon  the  anterior  wall,  the  former  being  usually  about  five  or  six 
inches  in  length,  and  the  latter  four  or  five.  It  is  attached  to  the  cervix 
of  the  uterus,  which  latter  projects  into  the  upper  extremity  of  the  canal. 

In  Structure  the  vagina  is  composed  of  a  mucous  lining,  a  layer  of 
erectile  tissue,  and  an  external  tunic  of  contractile  fibrous  tissue,  resembling 
the  dartos  of  the  scrotum.  The  upper  fourth  of  the  posterior  wall  of  the 

*  A  side  view  of  the  viscera  of  the  female  pelvis.  1.  The  symphysis  pubis ;  to  tha 
upper  part  of  which  the  tendon  of  the  rectus  muscle  is  attached.  2.  The  abdominal 
parietes.  3.  The  collection  of  fat,  forming  the  prominence  of  the  mons  Veneris.  4.  The 
urinary  bladder.  5.  The  entrance  of  the  left  ureter.  6.  The  canal  of  the  urethra,  con- 
verted into  a  mere  fissure  by  the  contraction  of  its  walls.  7.  The  meatus  urinarius. 
8.  The  clitoris,  with  its  prseputium,  divided  through  the  middle.  9.  The  left  nympha. 
10.  The  left  labium  majus.  11.  The  meatus  of  the  vagina,  narrowed  by  the  contraction 
of  its  sphincter.  12.  22.  The  canal  of  the  vagina,  upon  which  the  transverse  rugse  are 
apparent.  13.  The  thick  wall  of  separation  between  the  base  of  the  bladder  and  the 
vagina.  14.  The  wall  of  separation  between  the  vagina  and  rectum.  15.  The  perineum, 
16.  The  os  uteri.  17.  Its  cervix.  18.  The  fundus  uteri.  The  cavitas  uteri  is  seen  along 
the  centre  of  the  organ.  19.  The  rectum,  showing  the  disposition  of  its  mucous  mem- 
brane. 20.  The  anus.  21.  The  upper  part  of  the  rectum,  invested  by  the  peritoneum. 
23.  The  utero-vesical  fold  of  peritoneum.  The  recto-uterine  fold  is  seen  between  the 
rectum  and  the  posterior  wall  of  the  vagina.  24.  The  reflexion  of  the  peritoneum,  from 
the  apex  of  the  bladder  upon  the  urachus  to  the  internal  surface  of  the  abdomir\»i  pa- 
rietes. 25.  The  last  lumbar  vertebra.  20.  The  sacrum.  27.  The  coccyx. 

46*  2ic 


546  VAGINA — UTERUS. 

vagina  is  covered,  on  its  pelvic  surface,  by  the  peritoneum ;  \vhile  in  front 
the  peritoneum  is  reflected  from  the  upper  part  of  the  cervix  of  the  uterus 
to  the  posterior  surface  of  the  bladder.  On  each  side  it  gives  attachment, 
superiorly,  to  the  broad  ligaments  of  the  uterus ;  and,  inferiorly,  to  the 
pelvic  fascia  and  levatores  ani. 

The  Mucous  membrane  presents  a  number  of  transverse  papilla  or  rugae 
upon  the  upper  and  lower  surfaces  of  the  canal,  the  rugas  extending  out- 
wards on  each  side  from  a  middle  raphe.  The  transverse  papillae  and 
raphe  are  more  apparent  upon  the  upper  than  upon  the  lower  surface,  and 
the  two  raphe'  are  called  the  columns  of  the  vagina.  The  mucous  mem- 
brane is  covered  by  a  thin  cuticular  epithelium,  which  is  continued  from 
the  labia,  and  terminates  by  a  fringed  border  at  about  the  middle  of  the 
cervix  uteri. 

The  Middle  or  erectile  layer  consists  of  erectile  tissue  enclosed  between 
two  layers  of  fibrous  membrane  ;  this  layer  is  thickest  near  the  commence- 
ment of  the  vagina,  and  becomes  gradually  thinner  as  it  approaches  the 
uterus. 

The  External,  or  dartoid  layer  of  the  vagina,  serves  to  connect  it  to  the 
surrounding  viscera.  Thus,  it  is  very  closely  adherent  to  the  under  sur- 
face of  the  bladder,  and  drags  that  organ  down  with  it  in  prolapsus  uteri. 
To  the  rectum  it  is  less  closely  connected,  and  that  intestine  is  therefore 
less  frequently  affected  in  prolapsus. 

UTERUS. 

The  Uterus  is  a  flattened  organ  of  a  pyriform  shape,  having  the  base 
directed  upwards  and  forwards,  and  the  apex  downwards  and  backwards 
in  the  line  of  the  axis  of  the  inlet  of  the  pelvis,  and  forming  a  considerable 
angle  with  the  course  of  the  vagina.  It  is  convex  on  its  posterior  surface, 
and  somewhat  flattened  upon  its  anterior  aspect.  In  the  unimpregnated 
state  it  is  about  three  inches  in  length,  two  in  breadth  across  its  broadest 

Fig.  242« 


•  The  uterus  with  its  appendages  viewed  on  their  anterior  aspect.  1.  The  body  of 
ibe  uterus.  2.  Its  fundus.  3.  Its  cervix.  4.  The  os  uteri.  5.  The  vagina ;  the  num- 
ber is  placed  on  the  posterior  raph6  or  columna,  from  which  the  transverse  rugae  are 
seen  passing  off  at  each  side.  6.  6.  The  broad  ligament  of  the  uterus.  7.  A  convexity 
of  the  broad  ligament  formed  by  the  ovary.  8,  8.  The  round  ligaments  of  the  uterus. 
9,  9.  The  Fallopian  tubes.  10,  10.  The  fimbriated  extremities  of  the  Fallopian  tubes; 
on  the  left  side  the  mouth  of  the  tube  is  turned  forwards  in  order  to  show  its  ostium 
abdominale.  11.  The  ovary.  12.  The  utero-ovarian  ligament.  13.  The  Fallopio-ova- 
tian  ligament,  upon  which  some  small  fimbriae  are  continued  for  a  short  distance.  14. 
The  peritoneum  of  the  anterior  surface'of  the  uterus.  This  membrane  is  removed  on 
die  left  side,  but  on  the  right  is  continuous  with  the  anterior  layer  of  the  broad  ligament. 


STRUCTURE    OF    THE    UTERUS. 


547 


part,  and  one  in  thickness,  and  is  divisible  into  fundus,  body,  cervix,  and 
os  uteri.  At  the  period  of  puberty  the  uterus  weighs  about  one  ounce  and 
a  half;  after  parturition  from  two  to  three  ounces ;  and  at  the  ninth  month 
of  utero-gestation  from  two  to  four  pounds. 

The  Fundus  and  body  are  enclosed  in  a  duplicature  of  peritoneum, 
which  is  connected  with  the  sides  of  the  pelvis,  and  forms  a  transverse 
septum  between  the  bladder  and  rectum.  The  folds  formed  by  this  du- 
plicature of  peritoneum  on  either  side  of  the  organ  are  the  broad  ligaments 
of  the  uterus.  The  cervix  is  the  lower  portion  of  the  organ  ;  it  is  distin- 
guished from  the  body  by  a  well-marked  constriction  ;  around  its  circum- 
ference is  attached  the  upper  end  of  the  vagina,  and  at  its  extremity  is  an 
opening  which  is  nearly  round  in  the  virgin,  and  transverse  after  parturi- 
tion, the  os  uteri,  bounded  before  and  behind  by  two  labia ;  the  anterior 
labium  being  the  most  thick,  and  the  posterior  somewhat  the  longest. 
The  opening  of  the  os  uteri  is  of  considerable  size,  and  is  named  the  ori- 
ficium  uteri  externum ;  the  canal  then  becomes  narro\ved,  and  at  the 
upper  end  of  the  cervix  is  constricted  into  a  smaller  opening,  the  orificium 
internum.*  At  this  point  the  canal  of  the  cervix  expands  into  the  shallow 
triangular  cavity  of  the  uterus,  the  infe- 
rior angle  corresponding  with  the  ori-  Fis-  243-t 
ficium  internum,  and  the  two  superior 
angles,  which  are  funnel-shaped,  and  re- 
present the  original  bicornute  condition 
of  the  organ,  with  the  commencement  of 
the  Fallopian  tubes.  In  the  canal  of  the 
cervix  uteri  are  two  or  three  longitudinal 
folds,  to  which  numerous  oblique  folds 
converge  so  as  to  give  the  idea  of 
branches  from  the  stem  of  a-'tree  ;  hence 
this  appearance  has  been  denominated 
the  arbor  vita  uterina.  Between  these 
folds,  and  around  the  os  uteri,  are  nu- 
merous mucous  follicles.  It  is  the  closure 
of  the  mouth  of  one  of  these  follicles,  and 
the  subsequent  distention  of  the  follicle 
with  its  proper  secretion,  that  occasions 
those  vesicular  appearances,  so  often 
noticed  within  the  mouth  and  cervix  of 
the  uterus,  called  the  ovula  ofNaboth. 

Structure. — The  uterus  is  composed 
of  three  tunics :  of  an  external  or  serous 
coat,  derived  from  the  peritoneum,  which  constitutes  the  duplicatures  on 
each  side  of  the  organ  called  the  broad  ligaments  ;  of  a  middle  or  muscu- 
lar coat,  which  gives  thickness  and  bulk  to  the  uterus ;  and  of  an  internal 
or  mucous  membrane,  which  lines  its  interior,  and  is  continuous  on  the  one 
hand  with  the  mucous  lining  of  the  Fallopian  tubes,  and  on  the  other  with 
that  of  the  vagina.  In  the  unimpregnated  state  the  muscular  coat  is  ex- 
ceedingly condensed  in  texture,  offers  resistance  to  section  with  the  scalpel, 

*  The  orificium  internum  is  not  unfrequently  obliterated  in  old  persons.     Indeed, 
this  obliteration  is  so  common,  as  to  have  induced  Mayer  to  regard  it  as  normal. 

j-  Section  of  the  uterus  (transverse).    The  two  bristles  are  introduced  into  the  orifice* 
»f  the  Fallopian  tubes. 


548  VESSELS    AND    NERVES    OF    THE    UTERUS. 

and  appears  to  be  composed  of  whitish  fibres  inextricably  interlaced  and 
mingled  with  blood-vessels.  In  the  impregnated  uterus  the  fibres  are  of 
large  size,  and  distinct,  and  are  disposed  in  two  layers,  superficial  and 
deep.  The  superficial  layer  consists  of  fibres  which  pursue  a  vertical 
direction,  some  being  longitudinal,  and  others  oblique.  The  longitudinal 
fibres  are  found  principally  on  the  middle  line,  forming  a  thin  plane  upon 
the  anterior  and  posterior  face  of  the  organ  and  upon  its  fundus.  Th 
oblique  fibres  occupy  chiefly  the  sides  and  the  fundus.  At  the  angles  of 
the  uterus  the  fibres  of  the  superficial  layer  are  continued  outwards  upon 
the  Fallopian  tubes,  and  into  the  round  ligaments  and  ligaments  of  the 
ovaries.  The  deep  layer  consists  of  two  Hollow  cones  of  circular  fibres 
having  their  apex  at  the  openings  of  the  Fallopian  tubes,  and  intermin- 
gling with  each  other  by  their  bases  on  the  body  of  the  organ.  These 
fibres  are  continuous  with  the  deep  muscular  layer  of  the  Fallopian  tubes, 
and  indicate  the  primitive  formation  of  the  uterus  by  the  blending  of  these 
two  canals.  Around  the  cervix  uteri  the  muscular  fibres  assume  a  circular 
form  interlacing  with  and  crossing  each  other  at  acute  angles.  The 
mucous  membrane  is  provided  with  a  columnar  ciliated  epithelium,  which 
extends  from  the  middle  of  the  cervix  uteri  to  the  extremities  of  the  Fallo- 
pian tubes. 

Vessels  and  Nerves. — The  Arteries  of  the  uterus  are  the  uterine  from 
the  internal  iliac,  and  the  spermatic  from  the  aorta.  The  Veins  are  large 
and  remarkable ;  in  the  impregnated  uterus  they  are  called  sinuses,  and 
consist  of  canals  channeled  through  the  substance  of  the  organ,  being 
merely  lined  by  the  internal  membrane  of  the  veins.  They  terminate  on 
each  side  of  the  uterus  in  the  uterine  plexuses.  The  lymphatics  terminate 
in  the  lumbar  glands. 

The  Nerves  of  the  uterus  are  derived  from  the  hypogastric  and  sper- 
matic plexuses,  and  from  the  sacral  plexus.  They  have  been  made  the 
subject  of  special  investigation  by  Dr.  Robert  Lee,  who  has  successfully 
repaired  the  omission  made  by  Dr.  William  Hunter,  in  this  part  of  the 
anatomy  of  the  organ.  In  his  numerous  dissections  of  the  uterus,  both  in 
the  unimpregnated  and  gravid  state,  Dr.  Lee  has  made  the  discovery  of 
several  large  nervous  ganglia  and  plexuses.  The  principal  of  these,  situ- 
ated on  each  side  of  the  cervix  uteri,  immediately  behind  the  ureter,  he 
terms  the  hypogastric  ganglion;  it  receives  the  greater  number  of  the 
nerves  from  the  hypogastric  and  sacral  plexus,  and  distributes  branches  to 
the  uterus,  vagina,  bladder,  and  rectum.  Of  the  branches  to  the  uterus, 
a  large  fasciculus  proceeds  upwards  by  the  side  of  the  organ  towards  its 
angle,  where  they  communicate  with  branches  of  the  spermatic  plexus, 
and  form  another  large  ganglion,  which  he  designates  the  spermatic  gan- 
glion, and  which  supplies  the  fundus  uteri.  Besides  these,  Dr.  Lee  de- 
scribes vesical  and  vaginal  ganglia,  and  anterior  and  posterior  subperitoneal 
ganglia  and  plexuses,  which  communicate  with  the  preceding,  and  consti- 
tute an  extensive  nervous  network  over  the  entire  uterus.  Dr.  Lee  con- 
cludes his  observations  by  remarking: — "These  dissections  prove  that  the 
human  uterus  possesses  a  great  system  of  nerves,  wThich  enlarges  with  the 
coats,  blood-vessels,  and  absorbents,  during  pregnancy,  and  which  returns 
after  parturition  to  its  original  condition  before  conception  takes  place.  It 
is  chiefly  by  the  influence  of  these  nerves  that  the  uterus  performs  the 
varied  functions  of  menstruation,  conception,  and  parturition,  and  it  is 
solely  by  their  means  that  the  whole  fabric  of  the  nervous  system  sympa- 


APPENDAGES    OF    THE    UTERUS.  549 

tfrises  with  the  different  morbid  affections  of  the  uterus.  If  these  nerves 
of  the  uterus  could  not  be  demonstrated,  its  physiology  and  pathology 
would  be  completely  inexplicable."* 

APPENDAGES    OF    THE    UTERUS. 

The  Jippendages  of  the  uterus  are  enclosed  by  the  lateral  duplicatures  of 
peritoneum,  called  the  broad  ligaments.  They  are  the  Fallopian  tubes  and 
ovaries. 

The  FALLOPIANJ  TUBES  or  oviducts,  the  uterine  trumpets  of  the  French 
writers,  are  situated  in  the  upper  border  of  the  broad  ligaments,  and  are 
connected  with  the  superior  angles  of  the  uterus.  They  are  somewhat 
trumpet- shaped,  being  smaller  at  the  uterine  than  at  the  free  extremity, 
and  narrower  in  the  middle  than  at  either  end.  Each  tube  is  about  four 
or  five  inches  in  length,  and  more  or  less  flexuous  in  its  course.  The 
canal  of  the  Fallopian  tube  is  exceedingly  minute ;  its  inner  extremity 
opens  by  means  of  the  ostium  uterinum  into  the  upper  angle  of  the  cavity 
of  the  uterus,  and  the  opposite  end  into  the  cavity  of  the  peritoneum.  The 
free  or  expanded  extremity  of  the  Fallopian  tube  presents  a  double  and 
sometimes  a  triple  series  of  small  processes  or  fringes,  which  surround  the 
margin  of  the  trumpet  or  funnel-shaped  opening,  the  ostium  abdominale. 
This  fringe-like  appendage  to  the  end  of  the  tube  has  gained  for  it  the 
appellation  of  the  fimbriated  extremity ;  and  the  remarkable  manner  in 
which  this  circular  fringe  applies  itself  to  the  surface  of  the  ovary  during 
sexual  excitement,  the  additional  title  of  inorsus  diaboli.  A  short  liga- 
mentous  cord  proceeds  from  the  fimbriated  extremity  to  be  attached  to  the 
distal  end  of  the  ovary,  and  serves  to  guide  the  tube  in  its  seizure  of  that 
organ. 

The  Fallopian  tube  is  composed  of  three  tunics,  an  external  and  loose 
investment  derived  from  the  peritoneum;  a  middle  or  muscular  coat,  con- 
sisting of  circular  [internal]  and  longitudinal  [external]  fibres,  continuous 
with  those  of  the  uterus ;  and  an  internal  or  lining  mucous  membrane, 
which  is  continuous  on  the  one  hand  with  the  mucous  membrane  of  the 
uterus,  and  at  the  opposite  extremity  with  the  peritoneum.  In  the  minute 
canal  of  the  tube  the  mucous  membrane  is  thrown  into  longitudinal  folds 
or  rugae,  which  indicate  the  adaptation  of  the  tube  for  dilatation. 

The  OVARIES  are  two  oblong  flattened  and  oval  bodies  of  a  whitish 
colour,  situated  in  the  posterior  layer  of  peritoneum  of  the  broad  ligaments. 
They  are  connected  to  the  upper  angles  of  the  uterus  at  each  side  by 
means  of  a  rounded  cord,  consisting  chiefly  of  muscular  fibres  derived, 
from  the  uterus,  the  ligament  of  tfie  ovary.  By  the  opposite  extremity 
they  are  connected  by  another  and  a  shorter  ligament  to  the  fimbriated 
aperture  of  the  Fallopian  tube. 

In  structure  the  ovary  is  composed  of  a  cellulo-fibrous  parenchyma  or 
stroma,  traversed  by  blood-vessels,  and  enclosed  in  a  capsule  consisting 
of  three  layers :  a  vascular  layer,  which  is  situated  most  internally,  and 
sends  processes  inwards  to  the  interior  of  the  organ ;  a  middle  or  fibrous 
layer  of  considerable  density,  and  an  external  investment  of  peritoneum. 

*  Philosophical  Transactions  for  1842. 

•[•Gabriel  Fallopius,  a  nobleman  of  Modena,  was  one  of  the  founders  of  modern  ana- 
tomy. He  was  Professor  at  Ferrara.  then  at  Pisa,  and  afterwatds  succeeded  Vesalius 
at  Padua.  His  principal  observations  are  collected  in  a  work,  "  Observationes  Anato- 
niicae."  which  he  published  in  1501. 


550  EXTERNAL  ORGANS  OF  GENERATION. 

In  the  cells  of  the  stroma  of  the  ovary  the  small  vesicles  or  ovisacs  of  tL« 
future  ova,  the  Graafian  vesicles,  as  they  have  been  termed,  are  developed. 
There  are  usually  about  fifteen  fully  formed  Graafian  vesicles  in  each 
ovary ;  and  Dr.  Martin  Barry  has  shown  that  countless  numbers  of  micro- 
scopic ovisacs  exist  in  the  parenchyma  of  the  organ,  and  that  very  few  out 
of  these  are  perfected  so  as  to  produce  ova. 

After  conception,  a  yellow  spot,  the  corpus  luteum,  is  found  in  one  or 
both  ovaries.  The  corpus  luteum  is  a  globular  mass  of  yellow,  spongy 
tissue,  traversed  by  white  areolar  bands,  and  containing  in  its  centre  a 
small  cavity,  more  or  less  obliterated,  which  was  originally  occupied  by 
the  ovum.  The  interior  of  the  cavity  is  lined  by  a  puckered  membrane, 
the  remains  of  the  ovisac.  In  recent  corpora  lutea,  the  opening  by  which 
the  ovum  escaped  from  the  ovisac  through  the  capsule  of  the  ovary  is  dis- 
tinctly visible ;  when  closed,  a  small  cicatrix  may  be  seen  on  the  surface 
of  the  ovary  in  the  situation  of  the  opening.  A  similar  appearance  to  the 
preceding,  but  of  smaller  size,  and  without  a  central  cavity,  is  sometimes 
met  with  in  the  ovaries  of  the  virgin ;  this  is  a  false  corpus  luteum. 

Vessels  and  Nerves. — The  JJrteries  of  the  ovaries  are  the  spermatic; 
their  nerves  are  derived  from  the  spermatic  plexus. 

The  ROUND  LIGAMENTS  are  two  muscular  and  fibrous  cords  situated  be- 
tween the  layers  of  the  broad  ligaments,  and  extending  from  the  upper 
angles  of  the  uterus,  and  along  the  spermatic  canals  to  the  labia  rnajora, 
in  which  they  are  lost.  They  are  accompanied  by  a  small  artery,  by 
several  filaments  of  the  spermatic  plexus  of  nerves,  and  by  a  plexus  of 
veins.  The  latter  occasionally  become  varicose,  and  form  a  small  tumour 
at  the  external  abdominal  ring,  which  has  been  mistaken  for  inguinal 
hernia.  The  round  ligaments  serve  to  retain  the  uterus  in  its  proper  po- 
sition in  the  pelvis,  and,  during  utero-gestation,  to  draw  the  anterior  sur- 
face of  the  organ  against  the  abdominal  parietes. 

EXTERNAL  ORGANS  OF  GENERATION. 

The  female  organs  of  generation  are  divisible  into  the  internal  and  ex- 
ternal :  the  internal  are  contained  within  the  pelvis,  and  have  been  already 
described ;  they  are  the  vagina,  uterus,  ovaries,  and  Fallopian  tubes. 
The  external  organs  are  the  mons  Veneris,  labia  majora,  labia  minora, 
clitoris,  meatus  urinarius,  and  the  opening  of  the  vagina. 

The  Mons  Veneris  is  the  eminence  of  integument, 
situated  upon  the  front  of  the  ossa  pubis.  Its  are- 
olar tissue  is  loaded  with  adipose  substance,  and  the 
surface  covered  with  hairs. 

The  Labia  rnajora  are  two  large  longitudinal  folds 
of  integument,  consisting  of  fat  and  loose  areolar 
tissue.  They  enclose  an  elliptical  fissure,  the  com- 
mon urino-sexual  opening  or  vulva.  The  vulva 
receives  the  inferior  opening  of  the  urethra  and  va- 
gina, and  is  bounded  anteriorly  by  the  commissura 
superior,  and  posteriorly  by  the  commissura  inferior. 
Stretching  across  the  posterior  commissure  is  a  small 
transverse  fold,  \hefrcenulum  labiorum  or  fourchette, 
which  is  ruptured  during  parturition  ;  and  immedi 
ately  within  this  fold  is  a  small  cavity,  the  fossa 


MAMMARY    GLANDS.  551 

navicutaris.  The  length  of  the  perineum  is  measured  from  the  posterior 
commissure  to  the  margin  of  the  anus,  and  is  usually  not  more  than  an 
inch.  The  external  surface  of  the  labia  is  covered  with  hairs ;  the  inner 
surface  is  smooth,  and  lined  by  mucous  membrane,  which  contains  a  num- 
ber of  sebiparous  follicles,  and  is  covered  by  a  thin  cuticular  epithelium. 
The  use  of  the  labia  majora  is  to  favour  the  extension  of  the  vulva  during 
parturition ;  for,  in  the  passage  of  the  head  of  the  foetus,  the  labia  are  un- 
folded and  completely  effaced. 

The  Labia  minora,  or  nymphce,  are  two  smaller  folds,  situated  within 
the  labia  majora.  Superiorly  they  are  divided  into  two  processes,  which 
surround  the  glans  clitoridis,  the  superior  fold  forming  the  praeputium  cli- 
toridis,  and  the  inferior  its  frsenulum.  Inferiorly,  they  dimmish  gradually 
in  size,  and  are  lost  on  the  sides  of  the  opening  of  the  vagina.  The 
nymphae  consist  of  mucous  membrane,  covered  by  a  thin  cuticular  epi- 
thelium. They  are  provided  with  a  number  of  sebiparous  follicles,  and 
contain,  in  their  interior,  a  layer  of  erectile  tissue. 

The  Clitoris  is  a  small  elongated  organ  situated  in  front  of  the  ossa 
pubis,  and  supported  by  a  suspensory  ligament.  It  is  formed  by  a  small 
body,  which  is  analogous  to  the  corpus  cavernosum  of  the  penis,  and,  like 
it,  arises  from  the  ramus  of  the  os  pubis  and  ischium  on  each  side,  by  two 
crura.  The  extremity  of  the  clitoris  is  called  its  glans.  It  is  composed 
of  erectile  tissue,  enclosed  in  a  dense  layer  of  fibrous  membrane,  and  is 
susceptible  of  erection.  Like  the  penis,  it  is  provided  with  two  small 
muscles,  the  erectores  clitoridis. 

At  about  an  inch  behind  the  clitoris  is  the  entrance  of  the  vagina,  an  el- 
liptical opening,  marked  by  a  prominent  margin.  The  entrance  to  the 
vagina  is  closed  in  the  virgin  by  a  membrane  of  a  semilunar  form,  which 
is  stretched  across  the  opening ;  this  is  the  hymen.  Sometimes  the  mem- 
brane forms  a  complete  septum,  and  gives  rise  to  great  inconvenience  by 
preventing  the  escape  of  the  menstrual  effusion.  It  is  then  called  an  im- 
perf orate  hymen.  The  hymen  must  not  be  considered  a  necessary  accom- 
paniment of  virginity,  for  its  existence  is  very  uncertain.  When  present, 
it  assumes  a  variety  of  appearances :  it  may  be  a  membranous  fringe,  with 
a  round  opening  in  the  centre,  or  a  semilunar  fold,  leaving  an  opening  in 
front ;  or  a  transverse  septum,  having  an  opening  both  in  front  and  be- 
hind ;  or  a  vertical  band  with  an  opening  at  either  side. 

The  rupture  of  the  hymen,  or  its  rudimentary  existence,  gives  rise  to 
the  appearance  of  a  fringe  of  papillae  around  the  opening  of  the  vagina; 
these  are  called  carunculce  myrtiformes. 

The  triangular  smooth  surface  between  the  clitoris  and  the  entrance  of 
the  vagina,  which  is  bounded  on  each  side  by  the  upper  portions  of  the 
nymphae,  is  the  vestibule. 

At  the  upper  angle  of  the  vagina  is  an  elevation  formed  by  the  promi- 
nence of  the  upper  wall  of  the  canal,  and  analogous  to  the  bulb  of  the 
urethra  of  the  male ;  and  immediately  hi  front  of  this  tubercle,  and  sur- 
rounded by  it,  is  the  opening  of  the  urethra,  the  meatus  urinarius. 

MAMMARY    GLANDS. 

The  Mamma  are  situated  in  the  pectoral  region,  and  are  separated  from 
the  pectoralis  major  muscle  by  a  thin  layer  of  superficial  fascia.  They 
exist  in  the  male  as  well  as  in  thj  female,  but  in  a  rudimentary  state, 


552  ANATOMY    OF   THE    FCETUS. 

unless  excited  into  growth  by  some  peculiar  action,  such  as  the  loss  or 
atrophy  of  the  testes. 

Their  base  is  somewhat  elliptical,  the  long  diameter  corresponding  with 
the  direction  of  the  fibres  of  the  pectoralis  major  muscle ;  and  the  left 
mamma  is  generally  a  little  larger  than  the  right. 

Near  the  centre  of  the  convexity  of  each  mamma  is  a  small  prominence 
of  the  integument,  called  the  nipple,  which  is  surrounded  by  an  areola 
having  a  coloured  tint.  In  the  female  before  impregnation,  the  colour  of 
the  areola  is  a  delicate  pink ;  after  impregnation,  it  assumes  a  brownish 
hue,  which  deepens  in  colour  as  pregnancy  advances ;  and  after  the  birth 
of  a  child,  the  brownish  tint  continues  through  life. 

The  areola  is  furnished  with  a  considerable  number  of  sebiparous  folli- 
cles, which  secrete  a  peculiar  fatty  substance  for  the  protection  of -the  deli- 
cate integument  around  the  nipple.  During  suckling  these  follicles  are 
increased  in  size,  and  have  the  appearance  of  small  pimples,  projecting 
from  the  skin.  At  this  period  they  serve  by  their  increased  secretion  to 
defend  the  nipple  and  areola  from  the  excoriating  action  of  the  saliva  of 
the  infant. 

In  Structure,  the  mamma  is  a  conglomerate  gland,  and  consists  of  lobes, 
which  are  held  together  by  a  dense  and  firm  areolar  tissue ;  the  lobes  are 
composed  of  lobules,  and  the  lobules  of  minute  csecal  vesicles,  the  ulti- 
mate terminations  of  the  excretory  ducts. 

The  excretory  ducts  (tubuli  lactiferi),  from  ten  to  fifteen  in  number, 
commence  by  small  openings  at  the  apex  of  the  nipple,  and  pass  inwards, 
parallel  with  each  other,  towards  the  central  part  of  the  gland,  where  they 
form  dilatations  (ampulla?),  and  give  off  numerous  branches  to  ramify 
through  the  gland  to  their  ultimate  terminations  in  the  minute  lobules. 

The  ducts  and  ceecal  vesicles  are  lined,  throughout,  by  a  mucous  mem- 
brane, which  is  continuous  at  the  apex  of  the  nipple  with  the  integument. 

In  the  nipple  the  excretory  ducts  are  surrounded  by  a  tissue  analogous 
to  the  dartos  of  the  scrotum,  to  which  the  power  of  erectility  of  the  nipple 
seems  due.  There  is  no  appearance  of  any  structure  resembling  erectile 
tissue. 

Vessels  and  Nerves. — The  mammas  are  supplied  with  arteries  from  the 
thoracic  branches  of  the  axillary,  from  the  intercostals,  and  from  the  in- 
ternal mammary. 

The  Lymphatics  follow  the  border  of  the  pectoralis  major  to  the  axillary 
glands. 

The  Nerves  are  derived  from  the  thoracic  and  intercostals. 


CHAPTER  XII. 

ANATOMY    OF   THE   FCETUS. 


THE  medium  weight  of  a  child  of  the  full  period,  at  birth,  is  seven 
pounds,  and  its  length  seventeen  inches  ;  the  extremes  of  weight  are  foui 
pounds  and  three  quarters,  and  ten  pounds ;  and  the  extremes  of  measure- 
ment fifteen  and  twenty  inches.  The  head  is  of  large  size,  and  lengthened 


FCETAL    CIRCULATION.  553 

from  before  backwards ;  the  face  small.  The  upper  extremities  are  greatly 
developed,  and  the  thorax  expanded  and  full.  The  upper  part  of  the 
abdomen  is  large,  from  the  great  size  of  the  liver  ;  the  lower  part  is  small 
and  conical.  And  the  lower  extremities  are  very  small  in  proportion  to 
the  rest  of  the  body.  The  external  genital  organs  are  very  large,  and  fully 
developed,  and  the  attachment  of  the  umbilicus  is  one  inch  farther  from 
the  vertex  of  the  head  than  from  the  soles  of  the  feet ;  and  one  inch  farther 
from  the  ensiform  cartilage  than  from  the  symphysis  pubis. 

OSSEOUS  SYSTEM.  —  The  development  of  the  osseous  system  has  been 
treated  of  in  the  first  chapter.  The  ligamentous  system  presents  no  pecu- 
liarity deserving  of  remark. 

MUSCULAR  SYSTEM.  —  The  muscles  of  the  foetus  at  birth  are  large  and 
fully  formed.  They  are  of  a  lighter  colour  than  those  of  the  adult,  and  of 
softer  texture.  The  transverse  stria;  on  the  fibres  of  animal  life  are  not 
distinguishable  until  the  sixth  month  of  foetal  life. 

VASCULAR  SYSTEM.  —  The  circulating  system  presents  several  peculiari- 
ties :  Istly,  In  the  heart ;  there  is  a  communication  between  the  two  auri- 
cles by  means  of  the  foramen  ovate.  2dly,  In  the  arterial  system ;  there 
is  a  communication  between  the  pulmonary  artery  and  descending  aorta, 
by  means  of  a  large  trunk,  the  ductus  arteriosus.  3dly,  Also  in  the  arterial 
system ;  the  internal  iliac  arteries,  under  the  name  of  hypogastric  and 
umbilical,  are  continued  from  the  foetus  to  the  placenta,  to  which  they  re- 
turn the  blood  which  has  circulated  in  the  system  of  the  foetus.  4thly,  In 
the  venous  system ;  there  is  a  communication  between  the  umbilical  vein 
and  the  inferior  vena  cava,  called  the  ductus  venosus. 

FOZTAL    CIRCULATION. 

The  pure  blood  is  brought  from  the  placenta  by  the  umbilical  vein.  The 
umbilical  vein  passes  through  the  umbilicus,  and  enters  the  liver,  where  it 
divides  into  several  branches,  which  may  be  arranged  under  three  heads : — 
Istly,  Two  or  three,  which  are  distributed  to  the  left  lobe.  2dly,  A  single 
branch,  which  communicates  with  the  portal  vein  in  the  transverse  fissure, 
and  supplies  the  right  lobe.  3dly,  A  large  branch,  the  ductus  venosus, 
which  passes  directly  backwards,  and  joins  the  inferior  cava.  In  the  in- 
ferior cava  the  pure  blood  becomes  mixed  with  that  which  is  returning 
from  the  lower  extremities  and  abdominal  viscera,  and  is  carried  through 
the  right  auricle,  (guided  by  the  Eustachian  valve)  and  through  the  fora- 
men ovale,  into  the  left  auricle.  From  the  left  auricle  it  passes  into  the 
left  ventricle,  and  from  the  left  ventricle  into  the  aorta,  whence  it  is  dis- 
tributed, by  means  of  the  carotid  and  subclavian  arteries,  principally  to 
the  head  and  upper  extremities.  From  the  head  and  upper  extremities, 
the  impure  blood  is  returned  by  the  superior  vena  cava  to  the  right  auricle  ; 
from  the  right  auricle,  it  is  propelled  into  the  right  ventricle  ;  and  from  the 
right  ventricle  into  the  pulmonary  artery.  In  the  adult,  the  blood  would 
now  be  circulated  through  the  lungs,  and  oxygenated ;  but  in  the  foetus 
the  lungs  are  solid,  and  almost  impervious.  Only  a  small  quantity  of  the 
blood  passes  therefore  into  the  lungs ;  the  greater  part  rushes  through  the 
ductus  arteriosus,  into  the  commencement  of  the  descending  aorta,  where 
it  becomes  mingled  with  that  portion  of  the  pure  blood  which  is  not  sent 
through  the  carotid  and  subclavian  arteries. 

Passing  along  the  aorta,  a  small  quantity  of  this  mixed  blood  is  distri 
47 


554 


FCETAL    CIRCULATION. 


Fig.  245*  buted  by  the  external  iliac  arteries  to  the 

lower  extremities ;  the  greater  portion  is 
conveyed  by  the  internal  iliac,  hypogas- 
tric, and  umbilical  arteries  to  the  pla- 
centa ;  the  hypogastric  arteries  proceed- 
ing from  the  internal  iliacs,  and  passing 
by  the  side  of  the  fundus  of  the  bladder, 
and  upwards  along  the  anterior  wall  of 
the  abdomen  to  the  umbilicus,  where 
'*";  they  become  the  umbilical  arteries. 
V  From  a  careful  consideration  of  this 
circulation,  we  perceive  —  1st.  That  the 
pure  blood  from  the  placenta  is  distri- 
buted in  considerable  quantity  to  the 
liver,  before  entering  the  general  circu- 
lation. Hence  arises  the  abundant  nutri- 
tion of  that  organ,  and  its  enormous  size 
in  comparison  with  other  viscera. 

2dly.  That  the  right  auricle  is  the 
scene  of  meeting  of  a  double  current ; 
the  one  coming  from  the  inferior  cava, 
the  other  from  the  superior,  and  that 
they  must  cross  each  other  in  their  re- 
spective course.  How  this  crossing  is 
effected  the  theorist  will  wonder ;  not  so 
the  practical  anatomist;  for  a  cursory 
examination  of  the  fcetal  heart  will  show, 
1.  That  the  direction  of  entrance  of  the 
two  vessels  is  so  opposite,  that  they  may 
discharge  their  currents  through  the 
same  cavity  without  admixture.  2.  That  the  inferior  cava  opens  almost 
directly  into  the  left  auricle.  3.  That  by  the  aid  of  the  Eustachian  valve, 
the  current  in  the  inferior  cava  will  be  almost  entirely  excluded  from  the 
right  ventricle. 

3dly.  That  the  blood  which  circulates  through  the  arch  of  the  aorta 
comes  directly  from  the  placenta ;  and,  although  mixed  with  the  impure 

*  The  foetal  circulation.  1.  The  umbilical  cord,  consisting  of  the  umbilical  vein  and 
two  umbilical  arteries;  proceeding  from  the  placenta  (2).  3.  The  umbilical  vein 
dividing  into  three  branches;  two  (4,  4),  to  be  distributed  to  the  liver;  and  one  (5), 
the  ductus  venosus,  which  enters  the  inferior  vena  cava  (6).  7.  The  portal  vein,  re- 
turning the  blood  from  the  intestines,  and  uniting  with  the  right  hepatic  branch.  8.  The 
right  auricle ;  the  course  of  the  blood  is  denoted  by  the  arrow,  proceeding  from  8,  to  9, 
the  left  auricle.  10.  The  left  ventricle  ;  the  blood  following  the  arrow  to  the  arch  of 
the  aorta  (11),  to  be  distributed  through  the  branches  given  off  by  the  arch  to  the  head 
and  upper  extremities.  The  arrows  12  and  13,  represent  the  return  of  the  blood  from 
the  head  and  upper  extremities  through  the  jugular  and  subclavian  veins,  to  the  supe- 
rior vena  cava  (14),  to  the  right  auricle  (8),  and  in  the  course  of  the  arrow  through  the 
right  ventricle  (15),  to  the  pulmonary  artery  (16).  17.  The  ductus  arteriosus,  which 
appears  to  be  a  proper  continuation  of  the  pulmonary  artery,  the  offsets  at  each  side  are 
the  right  and  left  pulmonary  artery  cut  off;  these  are  of  extremely  small  size  as  com- 
pared with  the  ductus  arteriosus.  The  ductus  arteriosus  joins  the  descending  aorta 
(18,  18),  which  divides  into  the  common  iliacs,  and  these  into  the  internal  iliacs,  which 
become  the  hypogastric  arteries  (19),  and  return  the  blood  along  the  umbilical  cord  tc 
the  placenta;  while  the  other  divisions,  the  external  iliacs  (20),  are  continued  into  the 
lower  extremities.  The  arrows  at  the  terminations  of  these  vessels  mark  the  return  of 
the  venous  blond  by  the  veins  to  the  'nferior  cava. 


u  u 


ORGANS   OF    SENSE.  555 

blood  of  the  inferior  cava,  yet  is  propelled  in  so  great  abundance  to  the 
head  and  upper  extremities,  as  to  provide  for  the  increased  nutrition  of 
those  important  parts,  and  prepare  them,  by  their  greater  size  and  deve- 
lopment, for  the  functions  which  they  are  required  to  perform  at  the  instant 
of  birth. 

4thly.  That  the  blood  circulating  in  the  descending  aorta  is  very  impure, 
being  obtained  principally  from  the  returning  current  in  the  superior  cava ; 
a  small  quantity  only  being  derived  from  the  left  ventricle.  Yet  is  it  from 
this  impure  blood  that  the  nutrition  of  the  lower  extremities  is  provided. 
Hence  we  are  not  surprised  at  their  insignificant  development  at  birth ; 
while  we  admire  the  providence  of  nature,  that  directs  the  nutrient  current, 
in  abundance,  to  the  organs  of  sense,  prehension,  and  deglutition,  organs 
so  necessary,  even  at  the  instant  of  birth,  to  the  safety  and  welfare  of  the 
creature. 

After  birth,  the  foramen  ovale  becomes  gradually  closed  by  a  membran- 
ous layer,  which  is  developed  from  the  margins  of  the  opening  from  below 
upwards,  and  completely  separates  the  two  auricles.  The  situation  of  the 
foramen  is  seen  in  the  adult  heart,  upon  the  septum  auricularum,  and  is 
called  the  fossa  ovalis  ;  the  prominent  margin  of  the  opening  is  the  annu~ 
lus  ovalis. 

As  soon  as  the  lungs  have  become  inflated  by  the  first  act  of  inspiration, 
the  blood  of  the  pulmonary  artery  rushes  through  its  right  and  left  branches 
into  the  lungs,  to  be  returned  to  the  left  auricle  by  the  pulmonary  veins. 
Thus  the  pulmonary  circulation  is  established.  Then  the  ductus  arteriosus 
contracts,  and  degenerates  into  an  impervious  fibrous  cord,  serving  in 
after  life  simply  as  a  bond  of  union  between  the  left  pulmonary  artery  and 
the  concavity  of  the  arch  of  the  aorta. 

The  current  through  the  umbilical  cord  being  arrested,  the  umbilical 
arteries  likewise  contract  and  become  impervious,  and  degenerate  into  the 
umbilical  ligaments  of  the  bladder. 

The  umbilical  vein  and  ductus  venosus,  also  deprived  of  their  circulating 
current,  become  reduced  to  fibrous  cords,  the  former  being  the  round  liga- 
ment of  the  liver,  and  the  latter  a  fibrous  band  which  may  be  traced  along 
the  fissure  for  the  ductus  venosus  to  the  inferior  vena  cava. 

NERVOUS  SYSTEM. — The  brain  is  very  soft,  almost  pulpy,  and  has  a 
reddish  tint  throughout ;  its  weight  at  birth,  relatively  to  the  entire  body, 
is  as  one  to  six,  and  the  difference  between  the  white  and  grey  substance 
is  not  well  marked.  The  nerves  are  firm  and  well  developed. 

ORGANS    OF    SENSE. 

Eye. — The  eyeballs  are  of  large  size  and  well  developed  at  birth.  The 
pupil  is  closed  by  a  vascular  membrane  called  the  membrana  pupillarist 
which  disappears  at  about  the  seventh  month.  Sometimes  it  remains  per- 
manently, and  produces  blindness.  It  consists  of  two  thin  membranous 
layers,  between  which  the  ciliary  arteries  are  prolonged  from  the  edge  of 
the  iris,  and  form  arches  and  loops  by  returning  to  it  again,  without  anas- 
tomosing with  those  of  the  opposite  side. 

The  removal  of  the  membrane  takes  place  by  the  contraction  of  these 
arches  and  loops  towards  the  edge  of  the  pupil.  The  capsule  of  the  lens 
is  extremely  vascular. 

Ear. — The  ear  is  remarkable  for  its  early  development ;  the  labyrinth 


556  THYMUS    GLAND. 

and  ossicula  auditus  are  ossified  at  an  early  period,  and  the  latter  are 
completely  formed  before  birth.  The  only  parts  remaining  incomplete 
are  the  mastoid  cells,  and  the  meatus  auditorius.  The  membrana  tym- 
pani  in  the  foetal  head  is  very  oblique,  occupying  almost  the  basilar  surface 
of  the  skull ;  hence  probably  arises  a  deficient  acuteness  in  the  perception 
of  sound.  It  is  also  extremely  vascular. 

Nose. — The  sense  of  smell  is  imperfect  in  the  infant,  as  may  be  inferred 
from  the  small  capacity  of  the  nasal  fossae,  and  the  non-development  of  the 
ethmoid,  sphenoid,  frontal,  and  maxillary  sinuses. 

THYROID     GLAND. 

The  Thyroid  gland  is  of  large  size  in  the  foetus,  and  is  developed  by 
two  lateral  halves,  which  approach  and  become  connected  at  the  middle 
line  so  as  to  constitute  a  single  gland.  It  is  doubtful  whether  it  performs 
any  special  function  in  foetal  life. 

THYMUS     GLAND. 

The  Thymus  gland*  consists  "  of  a  thoracic  and  a  cervical  portion  on 
each  side.  The  former  is  situated  in  the  anterior  mediastinum,  and  the 
latter  is  placed  in  the  neck  just  above  the  first  bone  of  the  sternum,  and 
behind  the  sterno-hyoidei  and  sterno-thyroidei  muscles."  It  extends  up- 
wards from  the  fourth  rib  as  high  as  the  thyroid  gland,  resting  against  the 
pericardium,  and  separated  from  the  arch  of  the  aorta  and  great  vessels 
by  the  thoracic  fascia  in  the  chest,  and  lying  on  each  side  of  the  trachea 
in  the  neck. 

Although  described  usually  as  a  single  gland,  it  consists  actually  of 
two  lateral,  almost  symmetrical  glands,  connected  with  each  other  by  are- 
olar  tissue  only,  and  having  no  structural  communication  :  they  may  there- 
fore be  "properly  called,  a  right  and  left  thymus  gland." 

Between  the  second  and  third  months  of  embryonic  existence,  the  thy- 
mus is  so  small  as  to  be  only  "just  perceptible  ;"  and  continues  gradually 
increasing  with  the  growth  of  the  foetus  until  the  seventh.  At  the  eighth 
month  it  is  large ;  but,  during  the  ninth,  it  undergoes  a  sudden  change, 
assumes  a  greatly  increased  size,  and  at  birth  weighs  240  grains.  After 
birth  it  continues  to  enlarge  until  the  expiration  of  the  first  year,  when  it 
ceases  to  grow,  and  gradually  diminishes,  until  at  puberty  it  has  almost 
disappeared. 

The  thymus  is  a  conglomerate  gland,  being  composed  of  lobules  dis- 
posed in  a  spiral  form  around  a  central  cavity.  The  lobules  are  held 
together  by  a  firm  areolar  tissue  ("  reticulated"),  and  the  entire  gland  is 
enclosed  in  a  coarse  areolo-fibrous  capsule. 

The  Lobules  are  very  numerous,  and  vary  in  size  from  that  of  the  head 
of  a  pin  to  a  moderate-sized  pea.  Each  lobule  contains  in  its  interior  a 
small  cavity,  or  "  secretory  cell,"  and  several  of  these  cells  open  into  a 
small  "pouch"  which  is  situated  at  their  base,  and  leads  to  the  central 
cavity,  the  ^  reservoir  of  the  thymus." 

The  Reservoir  is  lined  in  its  interior  by  a  vascular  mucous  membrane, 
which  is  raised  into  ridges  by  a  layer  of  ligamentous  bands  situated  be- 

*  In  the  description  of  this  gland  I  have  adhered  closely  to  the  history  of  it  given  by 
Sir  Astley  Cooper,  in  his  beautiful  monograph  "  On  the  Anatomy  of  the  Thymus  Gland,1' 
1832. 


557 


Fig.  247.f 


beneath  it.  The  ligamentous  bands  proceed  in  various 
directions,  and  encircle  the  open  mouths  (pores)  of 
the  secretory  cells  and  pouches.  This  ligamentous 
layer  serves  to  keep  the  lobules  together,  and  pre- 
vent the  injurious  distension  of  the  cavity. 

When  either  gland  is  carefully  unravelled  by  re- 
moving the  areolar  capsule  and  vessels,  and  dissecting 
away  the  reticulated  areolar  tissue  which  retains  the 
lobules  in  contact,  the  reservoir,  from  being  folded  in 
a  serpentine  manner  upon  itself,  admits  of  being 
drawn  out  into  a  lengthened  tubular  cord^.  around 
which  the  lobules  are  clustered  in  a  spiral  manner,  and  resemble  knots 
upon  a  cord,  or  a  string  of  beads. 

The  reservoir,  pouches,  and  cells,  contain  a  white  fluid  "  like  chyle," 
or  "like  cream,  but  with  a  small  admixture  of  red  globules." 

In  an  examination  of  the  thymic  fluid  which  I  lately  (1840)  made,  with 
a  Powell  microscope  magnifying  600  times  linear  measure,  I  observed 
that  the  corpuscles  were  very  numerous,  smaller  than  the  blood  particles, 
globular  and  oval  in  form,  irregular  in  outline,  variable  in  size,  and  pro- 
vided with  •«  small  central  nucleus. 

In  the  human  foetus  this  fluid  has  been  found  by  Sir  Astley  Cooper  in 
too  small  proportion  to  be  submitted  to  chemical  analysis.  But  the  thy- 
mic fluid  of  the  fcetal  calf,  which  exists  in  great  abundance,  gave  the  fol- 

*  A  section  of  the  thymus  gland  at  the  eighth  month,  showing  its  anatomy.  This 
figure,  and  the  succeeding,  were  drawn  from  two  of  Sir  Astley  Cooper's  beautiful  pre- 
parations, with  the  kind  permission  of  their  possessor.  The  references  were  made  by 
Sir  Astley's  own  hand.  1.  The  cervical  portions  of  the  gland;  the  independence  of  the 
two  lateral  glands  is  well  marked.  2.  Secretory  cells  seen  on  the  cut  surface  of  the 
section ;  these  are  observed  in  all  parts  of  the  section.  3,  3.  The  pores  or  openings  of  • 
the  secretory  cells  and  pouches;  they  are  seen  dispersed  upon  the  whole  internal  sur- 
face of  the  great  central  cavity  or  reservoir.  The  continuity  of  the  reservoir  in  :l.e 
lower  or  thoracic  portion  of  the  gland,  with  the  cervical  portion,  is  seen  in  the  figure. 

•j-  The  course  and  termination  of  the  "  absorbent  ducts'"  of  the  thymus  of  the  calf; 
from  one  of  Sir  Astley  Cooper's  preparations.  1.  The  two  internal  jugular  veins.  2. 
The  superior  vena  cava.  3.  The  thoracic  duct,  dividing  into  two  branches,  which  re- 
unite previously  to  their  termination  in  the  root  of  the  left  jugular  vein.  4.  The  twu 
thymic  ducts;  that  on  the  left  side  opens  into  the  thoracic  duct,  and  that  on  the  right 
into  the  root  of  the  right  jugular  vein. 

$  See  the  beautiful  plates  in  Sir  Astley  Cooper's  work. 

47* 


558  FOETAL   LUNGS. 

loving  analytical*  results :  one  hundred  parts  of  the  fluid  contained  six 
teen  parts  of  solid  matter,  which  consisted  of, 

Incipient  fibrine, 

Albumen, 

Mucus,  and  muco-extractive  matter, 

Muriate  and  phosphate  of  potass 

Phosphate  of  soda, 

Phosphoric  acid,  a  trace. 

According  to  the  researches  of  Mr.  Simonf  and  Oesterlen  the  thymus  is 
composed  of  polygonal  and  mutually  flattened  membranous  cells,  measur- 
ing from  half  a  line  to  two  lines  in  diameter  and  arranged  in  conical  masses 
around  a  central  cavity.  Each  cell  is  surrounded  by  a  capillary  plexus 
and  connected  to  neighbouring  cells  by  areolar  tissue  intermingled  with 
elastic  fibres.  The  corpuscles  found  in  the  fluid  of  the  thymus  are  dotted 
nuclei  measuring  -gg^n  of  an  inch  in  diameter;  and  are  subject  to  conver- 
sion into  nucleated  cells  and  fat-cells. 

The  Jlrteries  of  the  thymus  gland  are  derived  from  the  internal  mam- 
mary, and  from  the  superior  and  inferior  thyroid. 

The  Veins  terminate  in  the  left  vena  innominata,  and  some  small  branches 
in  the  thyroid  veins. 

The  JVervet  are  very  minute,  and  are  derived  chiefly,  through  the  in- 
ternal mammary  plexus,  from  the  superior  thoracic  ganglion  of  the  sympa- 
thetic. Sir  Astley  Cooper  has  also  seen  a  branch  from  the  junction  of  the 
pneumogastric  and  sympathetic  pass  to  the  side  of  the  gland. 

The  Lymphatics  terminate  in  the  general  union  of  the  lymphatic  vessels 
at  the  junction  of  the  internal  jugular  and  subclavian  veins.  Sir  Astley 
Cooper  has  injected  them  only  once  in  the  human  foetus,  but  in  the  calf 
he  finds  two  large  lymphatic  ducts,  which  commence  in  the  upper  extre- 
mities of  the  glands,  and  pass  downwards,  to  terminate  at  the  junction  of 
the  jugular  and  subclavian  vein  at  each  side.  These  vessels  he  considers 
to  be  the  "absorbent  duds  of  the  glands;  lthymic  ducts;''  they  are  the 
carriers  of  the  fluid  from  the  thymus  into  the  veins." 

Sir  Astley  Cooper  concludes  his  anatomical  description  of  this  gland 
with  the  following  observations : — 

"As  the  thymus  secretes  all  the  parts  of  the  blood,  viz.  albumen,  fibrine, 
and  particles,  is  it  not  probable  that  the  gland  is  designed  to  prepare  a 
fluid  well  fitted  for  the  foetal  growth  and  nourishment  from  the  blood  of 
the  mother,  before  the  birth  of  the  foetus,  and,  consequently,  before  chyle 
is  formed  from  food? — and  this  process  continues  for  a  short  time  after 
birth,  the  quantity  of*  fluid  secreted  from  the  thymus  gradually  declining  as 
*bat  of  chylification  becomes  perfectly  established." 

FO2TAL    LUNGS. 

The  Lungs,  previously  to  the  act  of  inspiration,  are  dense  and  solid  in 
structure,  and  of  a  deep  red  colour.  Their  specific  gravity  is  greater  than 
water,  in  which  they  sink  to  the  bottom  ;  whereas  lung  which  has  respired 
will  float  upon  that  fluid.  The  specific  gravity  is,  however,  no  test  of  the 

*  This  analysis  was  conducted  by  Dr.  Dowler  of  Richmond, 
f  "A  Physiological  Essay  on  the  Thymus  Gland,"  4to.  1845. 


VISCERA    OF   THE   ABDOMEN.  559 

real  weight  of  the  lung,  the  respired  lung  being  actually  heavier  than  the 
fetal.  Thus  the  weight  of  the  foetal  lung,  at  about  the  middle  period  of 
uterine  life,  is  to  the  weight  of  the  body  as  1  to  60.*  But,  after  respira- 
tion, the  relative  weight  of  the  lung  to  the  entire  body  is  as  1  to  30. 


FCETAL    HEART. 


The  Heart  of  the  foetus  is  large  in  proportion  to  the  size  of  the  body ;  it 
is  also  developed  very  early,  representing  at  first  a  simple  vessel,  and  un- 
dergoing various  degrees  of  complication  until  it  arrives  at  the  compound 
character  which  it  presents  after  birth.  The  two  ventricles  form,  at  one 
period,  a  single  cavity,  which  is  afterwards  divided  into  two  by  the  septum 
ventriculorum.  The  two  auricles  communicate  up  to  the  moment  of  birth, 
the  septum  being  incomplete,  and  leaving  a  large  opening  between  them, 
\heforamen  ovale  (foramen  of  Botalf). 

The  Ductus  arteriosus  is  another  peculiarity  of  the  foetus  connected  with 
the  heart ;  it  is  a  communication  between  the  pulmonary  artery  and  the 
aorta.  It  degenerates  into  a  fibrous  cord  after  birth,  from  the  double 
cause,  of  a  diversion  in  the  current  of  the  blood  towards  the  lungs,  and 
from  the  pressure  of  the  left  bronchus,  caused  by  its  distension  with  air. 


VISCERA    OF    THE    ABDOMEN. 

At  an  early  period  of  uterine  life,  and  sometimes  at  the  period  of  birth, 
as  I  have  twice  observed  in  the  imperfectly  developed  foetus,  two  minute 
fibrous  threads  may  be  seen  passing  from  the  umbilicus  to  the  mesentery. 
These  are  the  remains  of  the  omphalo-mesenteric  vessels. 

The  Omphalo-mesenteric  are  the  first  developed  vessels  of  the  germ : 
they  ramify  upon  the  vesicula  umbilicalis,  or  yolk-bag,  and  supply  the 
newly  formed  alimentary  canal  of  the  embryo.  From  them,  as  from  a 
centre,  the  general  circulating  system  is  produced.  After  the  establish- 
ment of  the  placental  circulation  they  cease  to  carry  blood,  and  dwindle 
to  the  size  of  mere  threads,  which  may  be  easily  demonstrated  in  the  early 
periods  of  uterine  life ;  but  are  completely  removed,  excepting  under  pe- 
culiar circumstances,  at  a  later  period. 

The  Stomach  is  of  small  size,  and  the  great  extremity  but  little  deve- 
loped. It  is  also  more  vertical  in  direction  the  earlier  it  is  examined,  e 
position  that  would  seem  due  to  the  enormous  magnitude  of  the  liver,  anc 
particularly  of  its  left  lobe. 

The  Appendix  vermiformis  cesci  is  long  and  of  large  size,  and  is  con- 
tinued directly  from  the  central  part  of  the  cul-de-sac  of  the  caecum,  of 
which  it  appears  to  be  a  constricted  continuation.  This  is  the  character 
of  the  appendix  cseci  in  the  higher  quadrumana. 

The  large  intestines  are  filled  with  a  dark  green  viscous  secretion,  called 
meconium  (fA*jxwv,  poppy),  from  its  resemblance  to  the  inspissated  juice  of 
the  poppy. 

The  Pancreas  is  comparatively  larger  in  the  foetus  than  in  the  adult. 

The  Spleen  is  comparatively  smaller  in  the  foetus  than  in  the  adult. 

*  Cruveilhier,  Anatomie  Descriptive,  vol.  ii.  p.  621. 

•j-  Leonard  Botal,  of  Piedmont,  was  the  first  of  the  moderns  who  gave  an  account  of 
this  opening  in  a  work  published  in  1565.  His  description  is  very  imperfect.  The 
foramen  was  well  known  to  Galen. 


560  FCETAL    LIVER — TESTES. 

FCETAL    LIVER. 

The  Liver  is  the  first  formed  organ  in  the  embryo.  It  is  developed 
from  the  alimentary  canal,  and  at  about  the  third  week,  fills  the  whole 
abdomen,  and  is  one-half  the  weight  of  the  entire  embryo.  At  the  fourth 
month  the  liver  is  of  immense  size  in  proportion  to  the  bulk  of  the  foetus. 
At  birth  it  is  of  very  large  size,  and  occupies  the  whole  upper  part  of  the 
abdomen.  The  left  lobe  is  as  large  as  the  right,  and  the  falciform  liga- 
ment corresponds  with  the  middle  line  of  the  body.  The  liver  diminishes 
rapidly  after  birth,  probably  from  obliteration  of  the  umbilical  vein. 

KIDNEYS  AND  SUPRA-RENAL  CAPSULES. 

The  Kidneys  present  a  lobulated  appearance  in  the  foetus,  which  is  their 
permanent  type  amongst  some  animals,  as  the  bear,  the  otter,  and  cetacea. 

The  Supra-renal  capsules  are  organs  which  appear,  from  their  early  and 
considerable  development,  to  belong  especially  to  the  economy  of  the 
fetus.  They  are  distinctly  formed  at  the  second  month  of  embryonic  life, 
and  are  greater  in  size  and  weight  than  the  kidneys.  At  the  third  or  fourth 
month,  they  are  equalled  in  bulk  by  the  kidneys ;  and  at  birth,  they  are 
about  one-third  less  than  those  organs. 

VISCERA    OF    THE    PELVIS. 

The  Bladder  in  the  foatus  is  long  and  conical,  and  is  situated  altogether 
above  the  upper  border  of  the  ossa  pubis,  which  are  as  yet  small  and  un- 
developed. It  is,  indeed,  an  abdominal  viscus,  and  is  connected  supe- 
riorly with  a  fibrous  cord,  called  the  urachus,  of  which  it  appears  to  be  an 
expansion. 

The  Urachus  is  continued  upwards  to  the  umbilicus,  and  becomes  con- 
nected with  the  umbilical  cord.  In  animals  it  is  a  pervious  duct,  and  is 
continuous  with  one  of  the  membranes  of  the  embryo,  the  allantois.  It 
has  been  found  pervious  in  the  human  foetus,  and  the  urine  has  been  passed 
through  the  umbilicus.  Calculous  concretions  have  also  been  found  in  its 
course. 

The  Uterus,  in  the  early  periods  of  embryonic  existence,  appears  bifid, 
from  the  large  size  of  the  Fallopian  tubes,  and  the  small  development  of 
the  body  of  the  organ.  At  the  end  of  the  fourth  month,  the  body  assumes 
a  larger  bulk,  and  the  bifid  appearance  is  lost.  The  cervix  uteri  in  the 
foetus  is  larger  than  the  body  of  the  organ. 

The  Ovaries  are  situated,  like  the  testicles,  in  the  lumbar  region,  neai 
the  kidneys,  and  descend  from  thence,  gradually,  into  the  pelvis. 

TESTES. 

The  Testicles  in  the  embryo  are  situated  in  the  lumbar  regions,  imme- 
diately in  front  of  and  somewhat  below  the  kidneys.     They  have,  con 
nected  with  them  inferiorly,  a  peculiar  structure,  which  assists  in  their 
descent,  and  is  called  the  gubernaculum  testis. 

The  Gubernaculum  is  a  soft  and  conical  cord  composed  of  areolar  tissue 
containing  in  its  areolse  a  gelatiniform  fluid.  In  the  abdomen  it  lies  in 
front  of  the  psoas  muscle,  and  passes  along  the  spermatic  canal,  which  it 


DESCENT  OF  THE  TESTIS.  561 

serves  to  distend  for  the  passage  of  the  testis.  It  is  attached  by  its  supe- 
rior and  larger  extremity  to  the  lower  end  of  the  testis  and  epididymis,  and 
by  the  inferior  extremity  to  the  bottom  of  the  scrotum.  The  gubernaculum 
is  surrounded  by  a  thin  layer  of  muscular  fibres,  the  cremaster,  which  pass 
upwards  upon  this  body  to  be  attached  to  the  testis.  Inferiorly,  the  mus- 
cular fibres  divide  into  three  processes,  which,  according  to  Mr.  Curling,* 
are  thus  attached :  "  The  external  and  broadest  is  connected  to  Poupart's 
ligament  in  the  inguinal  canal;  the  middle  forms  a  lengthened  band, 
which  escapes  at  the  external  abdominal  ring,  and  descends  to  the  bottom 
of  the  scrotum,  where  it  joins  the  dartos ;  the  internal  passes  in  the  direc- 
tion inwards,  and  has  a  firm  attachment  to  the  os  pubis  and  sheath  of  the 
rectus  muscle.  Besides  these,  a  number  of  muscular  fibres  are  reflected 
from  the  internal  oblique  on  the  front  of  the  gubernaculum." 

The  Descent  of  the  testicle  is  gradual  and  progressive.  Between  the 
fifth  and  sixth  months  it  has  reached  the  lower  part  of  the  psoas  muscle, 
and  during  the  seventh  it  makes  its  way  through  the  spermatic  canal,  and 
descends  into  the  scrotum. 

While  situated  in  the  lumbar  region,  the  testis  and  gubernaculum  are 
placed  behind  the  peritoneum,  by  which  they  are  invested  upon  their  an- 
terior surface  and  sides.  As  they  descend,  the  investing  peritoneum  is 
carried  downwards  with  the  testis  into  the  scrotum,  forming  a  lengthened 

Fig.  248.-J-  Fig.  2494 


pouch,  which  by  its  upper  extremity  opens  into  the  cavity  of  the  perito- 
neum. The  upper  part  of  this  pouch,  being  compressed  by  the  spermatic 
canal,  is  gradually  obliterated,  the  obliteration  extending  downwards 
along  the  spermatic  cord  nearly  to  the  testis.  That  portion  of  the  perito- 
neum which  immediately  surrounds  the  testis  is,  by  the  above  process, 
cut  off  from^its  continuity  with  the  peritoneum,  and  is  termed  the  tunica 

*  See  an  excellent  paper  "  On  the  Structure  of  the  Gubernaculum,"  &c.,  by  Mr.  Curl- 
ing, Lecturer  on  Morbid  Anatomy  in  the  London  Hospital,  in  the  Lancet,  vol.  ii. 
1840-41,  p.  70. 

f  A  diagram  illustrating  the  descent  of  the  testis.  I.  The  testis.  2.  The  epididymis. 
3,  3.  The  peritoneum.  4.  The  pouch  formed  around  the  testis  by  the  peritoneum,  the 
future  cavity  of  the  tunica  vaginalis.  5.  The  pubic  portion  of  the  cremaster  attached  to 
the  lower  part  of  the  testis.  6.  The  portion  of  the  cremaster  attached  to  Poupart's  liga- 
ment. The  mode  of  eversion  of  the  cremaster  is  shown  by  these  lines.  7.  The  guber- 
naculum, attached  to  the  bottom  of  the  scrotum,  and  becoming  shortened  by  the  con- 
traction of  the  muscular  fibres  which  surround  it.  8,  8.  The  cavity  of  the  scrotum. 

$  ID  this  figure  the  testis  has  completed  its  descent.  The  gubernaculum  is  shortened 
to  its  utmost,  and  the  cremaster  completely  everted.  The  pouch  of  peritoneum  above 
the  testis  is  compressed  so  as  to  form  a  tubular  canal ;  1.  A  dotted  line  marks  the  point 
at  which  the  tunica  vaginalis  will  terminate  superiorly ;  and  the  number  2  its  cavity 
3.  The  peritoneal  cavity. 

2L 


562  DESCENT  OF  THE  TESTIS. 

vaginalis  ;  and  as  this  membrane  must  be  obviously  a  shut  sac,  one  por- 
tion of  it  investing  the  testis,  and  the  other  being  reflected  so  as  to  form  a 
loose  bag  around  it,  its  two  portions  have  received  the  appellations  of 
tunica  vaginalis  propria,  and  tunica  vaginalis  reflexa. 

The  descent  of  the  testis  is  effected  by  means  of  the  traction  of  the 
muscle  of  the  gubernaculum  (cremaster).  "  The  fibres,"  writes  Mr.  Curl- 
ing,* "proceeding  from  Poupart's  ligament  and  the  obliquus  internus, 
tend  to  guide  the  gland  into  the  inguinal  canal ;  those  attached  to  the  os 
pubis,  to  draw  it  below  the  abdominal  ring ;  and  the  process  descending 
to  the  scrotum,  to  direct  it  to  its  final  destination."  During  the  descent, 
"  the  muscle  of  the  testis  is  gradually  everted,  until,  when  the  transition 
is  completed,  it  forms  a  muscular  envelope  external  to  the  process  of  peri- 
toneum, which  surrounds  the  gland  and  the  front  of  the  cord."  "  The 
mass  composing  the  central  part  of  the  gubernaculum,  which  is  so  soft, 
lax,  and  yielding  as  in  every  way  to  facilitate  these  changes,  becomes  gra- 
dually diffused,  and,  after  the  arrival  of  the  testicle  in  the  scrotum,  con- 
tributes to  form  the  loose  cellular  tissue  which  afterwards  exists  so  abun- 
dantly in  this  part."  The  attachment  of  the  gubernaculum  to  the  bottom 
of  the  scrotum  is  indicated  throughout  life  by  distinct  traces. 

•  Loc.  cit. 


INDEX. 


A. 

Abdomen,  496 
Abdominal  regions,  496 
Abdominal  ring,  212,  266 
Abductor  oculi,  177 
Acetabulum,  116 
Acini,  519 
Adductor  oculi,  177 
Adipose  tissue,  136 
Air-cells,  494 
Albino,  452 

Alcock,  Dr.,  researches  of,  396 
Alimentary  canal,  501 
Allantpis,  560 
Amphi-arthrosis,  130 
Ampulla,  459 
Amygdalae,  503 

cerebri,  380 

Andersch,  notice  of,  404 
Annulus  ovalis,  478 
Antihelix,  456 
Antitragus,  455 
Antrum  of  Highmore,  74 

pylori,  506 
Anus,  509-514 
Aorta,  abdominal,  280 

arch,  279 

ascending,  279 

thoracic,  280 
Aortic  sinuses,  278 
Aponeurosis,  168 
Apophysis,  48 

Apparatus  ligamentosus  colli,  141 
Appendices  epiploicae,  501 
Appendix  vermiformis,  507 
Aqua  labyrinthi,  463 
Aqueductus  cochleae,  463 

vestibuli,  462 
Aqueduct  of  Sylvius,  379 
Aqueous  humour,  451 
Arachnoid  membrane,  370 
Arantius,  notice  of,  480 
Arbor  vitse,  382 

uterina,  547 
Arch,  femoral,  273 

palmar,  superficial,  308 
Arciform  fibres,  386 
Areola,  552 
Areolar  tissue,  136 
Arnold,  Frederick,  researches,  435 
ARTERIES. 

General  anatomy,  275 

structure,  277 

anastomotica,  femor.  326 
brachial,  304 


ARTERIES — continued. 
angular,  285 
aorta,  278 

articulares  genu,  327 
auricula  anterior.  268 

posterior,  287 
axillary,  300 
basilar,  296 
brachial,  303 
bronchial,  308 
bulbosi,  320 
calcanean,  332 
carotid,  common,  282 

external,  2S3 

internal,  291 
carpal  ulnar,  308 

radial,  306 
cavernosi,  320 
centralis  retinae,  293,  452 
cerebellar  interior,  297 

superior,  297 
cerebral,  293,  294 
cervicalis  anterior,  299 

posterior,  299 
choroidean,  294 
ciliary,  293 
circumflex  anterior,  302 

external,  325 
circumflex  ilii,  322,  324 

internal,  326 

posterior,  302 
coccygeal,  318 
cosliac,  310 
colic,  314,  315 
comes  nervi  ischiatici,  318 

phrenici,  300 
communicans  cerebri,  294 

pedis,  330 
coronaria  cordis,  281 

dextra,  281 

labii,  286 

einistra,  281 

ventriculi,  310 
corporis  bulbosi,  320 

cavernosi,  320 
cremasteric,  322 
cystic,  311 
dental,  289 
digitales  manus,  308 

pedis,  333 

dorsales  pollicis,  306 
dorsalis  linguae,  285 

carpi,  306 

hallucis,  330 

nasi,  293 

pedis,  333 

(563) 


564 


INDEX. 


ARTERIES — continued. 

penis,  320 

scapulae,  302 
emulgent,  315 
epigastric,  322 

superficial,  325 
ethmoidal,  293 
facial,  285 
femoral,  323 
frontal,  293 
gastric,  310 
gastro-duodenalis   311 

epiploica  dextra,  311 

sinistra,  311 
gluteal,  321 

inferior,  318 
hsemorrhoidal,  external,  319 

middle,  318 

superior,  315 

inferior,  318 
hepatic,  310 
ileo-colic,  313 
iliac,  common,  316 

external,  321 

internal,  317 
ileo-lumbar,  320 
infra-orbital,  290 
innominata,  281 
intercostal,  309 

anterior,  300 

superior,  299 
inter-osseous,  307,  308 
intestini  tenuis,  312 
ischiatic,  318 
labial,  286 
lachrymal,  292 
laryngeal,  285 
lateralis  nasi,  286 
lingual,  285 
lumbar,  315 
malleolar,  329 
mammary,  internal,  299 
masseteric,  286 
mastoid,  287 
maxillary,  internal,  288 
mediastinal,  300 
meningea,  anterior,  292 

inferior,  287 

media,  290 

parva,  290 

posterior,  297 
mesenteric,  312 

inferior,  315 
metacarpal,  306 
metatarsal,  330 
musculo-phrenic,  300 
nasal,  293 
obturator,  320 
occipital,  287 
cesophageal,  308 
ophthalmic,  292 
orbitar,  288 
palatine,  inferior,  286 

posterior,  290 
palpebral,  293 
pancreatica  magna,  311 
pancreatic®  parva?,  31 1 
pancreatico-duodenalis,  311 
parotidean,  287 
perforantes,  femoral,  326 

palmares,  306 

plantares,  332 
pericardiac,  300 
perineal,  superficial,  319 


ARTERIES — continued. 
peroneal,  331 

pharyngea  ascendens,  287 
phrenic,  309 
plantar,  external,  332 

internal,  332 
popliteal,  326 
princeps  cervicis,  287 

pollicis,  306 
profunda  cervicis,  299 

femoris,  325 

inferior,  304 

superior,  303 
pterygoid,  286 
pterygo-palatine,  290 
pudic,  external,  325 

internal,  318 
pulmonary,  334 
pyloric,  311 
radial,  304 
radialis  indicia,  306 
ranine,  285 
recurrens  interosseous,  308 

radialis,  305 

tibialis,  329 

ulnaris,  307 
renal,  315 
sacra  media,  316 

lateralis,  321 
scapular,  posterior,  299 
sigmoid,  315 
spermatic,  314 
spheno-palatine,  290 
spinal,  297 
splenic,  311 
stylo-mastoid,  287 
subclavian,  294 
sublingual,  285 
submaxillary,  286 
submental,  286 
subscapular,  302 
superficialis  cervicis,  299 

volte,  306 
supra-orbital,  293 
supra-renal,  315 

scapular,  298 
sural,  328 
tarsea,  330 
temporal,  288 
temporales  profundas,  290 
thoracic,  302 
thyroidea  inferior,  298 

media,  282 

superior,  284 
tibialis  antica,  328 

postica,  330 
transversalis  colli,  299 

faciei,  287 

humeri,  298 

perinei,  320 
tympanic,  289 
ulnar,  306 
ambilical,  317 
uterine,  320 
vaginal,  320 
vasa  brevia,  311 

intestini  tenuis,  312 
vertebral,  296 
vesical,  318 
Vidian,  291 
Arthrodia,  130 
Articulations,  137 
Arytenoid  cartilages,  486 
Arytenoid  glands,  491 


INDEX. 


565 


Auricles  of  the  heart,  477,  481 
Auriculo-ventricular  openings,  478,  431 

B. 

Barry,  Dr.,  researches  of,  550 

Base  of  the  brain,  382 

Bauhini,  valvula,  510 

Bell,  Sir  C.,  researches  of,  366 

Berzelius,  analysis  of  bone,  43 

Biliary  ducts,  525 

Bladder,  532 

BONES,  chemical  composition,  43 

development,  46 

general  anatomy,  43 

structure,  44 
astragalus,  124 
atlas,  51 
axis,  52 
calcis,  124 
carpus,  109 
clavicula,  103  , 

coccyx,  58 
costae,  102 
cuboides,  126 
cuneiforme  carpi,  110 

externum  tarsi,  125 

internum,  126 

medium,  123 
ethmoides,  72 
femur,  119 
fibula,  122 
frontale,  62 
humerus,  105 
hyoides,  99 
ilium,  114 
innominatum,  114 
ischium,  115 
lachrymale,  77 
magnum,  111 
malare,  77 

maxillare  superius,  74 
maxillare  inferius,  81 
metacarpus,  112 
metatarsus,  127 
nasi,  74 
naviculare,  125 
occipitale,  59 
palati,  77 
parietale,  61 
patella,  121 
phalanges  manus,  113 

_  pedis,  128 
pisiforme,  110 
pubis,  116 
radius,  107 
sacrum,  56 
scaphoides  carpi,  109 

tarsi,  125 
scapula,  103 
semilunare,  109 
eesamoidea  manus,  129 

pedis,  129 
sphenoides,  69 
sternum,  100 
tarsus,  124 
temporal,  64 
tibia,  121 
trapezpides,  111 
trapezium,  110 
triquetra,  84 
turbinatum  inferius,  80 

superius,  73 
ulna,  106 

48 


B  ONES— -cont  inued . 

uncilbrme,  112 

unguis,  77 

vertebra  prominens,  52 

vertebra  dentata,  52 

vertebrae,  cervical,  50 
dorsal,  53 
lumbar,  53 

vomer,  80 

Wormiana,  84 
Botal,  foramen  of,  559 

notice  of,  559 

Bowman,  Mr.,  researches  of,  170,  529 
Brain,  367 
Bronchi,  494 
Bronchial  cells,  494 

tubes,  494 
Bronchocele,  392 
Brunn,  Von,  notice  of,  512 
Brunner's  glands,  512 
Bulb,  corpus  spongiosum,  537 
Bulbi  fornicis,  384 
Bulbous  part  of  the  urethra,  539 
Bulbus  olfactorius,  394 
Bursae  mucosae,  137 

C. 

Caecum,  507 

Calamus  scriptorius,  380 
Calyces,  530 
Camper's  ligament,  269 
Canal  of  Fontana,  447 

Petit,  452 

Sylvius,  379 
Canals  of  Havers,  44 
Canthi,  453 
Capillaries,  276 
Capitula  Santorini,  486 
Capsule  of  Glisson,  521 
Capsules  supra-renal,  527 
Caput  gallinaginis,  539 
Cardia,  505 
Carpus,  109 
Cartilage,  46,  132 
CARTILAGES. 

inter-articular  of  the  clavicle,  150 

inter-articular  of  the  jaw,  144 

inter- articular  of  the  wrist,  155 

semilunar,  161 
Cartilaginification,  132 
Caruncula  lachrymalis,  454 

mammillaris,  384 
Carunculae  myrtiformes,  551 
Casserian  ganglion,  391 
Cauda  equina,  390 
Cava,  vena,  346 
Cementum,  94 
Centrum  ovale  majus,  373 

minus,  374 
Cerebellum,  381 
Cerebro-spinal  axis,  367 
Cerebrum,  372 
Ceruminous  follicles,  457 
Cervical  ganglia,  437 
Chambers  of  the  eye,  451 
Cheeks,  502 
Chiasma  nerv.  opt.  394 
Chorda  tympani,  402 
Chordae  longitudinales,  390 

tendineae,  479,  482 

vocales,  488 

Willisii,  368 
Choroid  membrane,  448 


566 


INDEX. 


Choroid  plexus,  375 
Ciliae,  453 
Ciliary  canal,  448 

ligament,  448 

processes,  448 
Circle  of  Willis,  298 
Circulation,  adult,  276 

foetal,  585 

Circulus  tonsillaris,  287 
Clitoris,  551 

Clivus  Blumenbachii,  69 
Cochlea,  463 

Cock,  Mr.,  researches  of,  407 
Cceliac  axis,  310 
Colon,  508 
Columna  nasi,  443 
Columnae  earner,  479,  482 
Commissures,  362,  378 

great,  373 
Conarium,  379 
Concha,  456 

Congestion  of  the  liver,  523 
Coni  renales,  529 

vasculosi,  543 
Conjunctiva,  454 
Converging  fibres,  388 
Cooper,  Sir  Astley,  researches  of,  557 
Corium,  469 
Cornea,  446 
Cornicula  laryngis,  486 
Cornu  Ammonis,  376 
Cornua  of  the  ventricles,  373,  375 
Corona  glandis,  536 
Coronary  valve,  478 
Corpora  albicantia,  384 

Arantii,  480 

cavernosa,  536 

geniculata,  378 

Malpighiana,  530 

mammillaria,  384 

olivaria,  385 

pisiformia,  384 

pyramidalia,  385 

quadrigemina,  379 

restiformia,  386 

striata,  374 
Corpus  callosum,  37 

cavernosum,  536 

dentatum,  382 

fimbriatum,  376 

geniculatum  externum,  378 
internum,  378 

Highmorianum,  542 

luteum,  550 

psalloides,  398 

rhomboideum,  382 

spongiosum,  537 

striatum,  374 
Costal  cartilages,  102 
Cotunnius,  notice  of,  463 
Cowper's  glands,  540 
Cranial  nerves,  392 
Cribriform  fascia,  272 
Cricoid  cartilage,  486 
Crico-thyroid  membrane,  487 
Crura  cerebelli,  382 

cerebri,  378 

penis,  536 
Crural  canal,  272 

ring,  273 

Crystalline  lens,  451 
Cuneiform  cartilages,  486 
Cupola,  464 
Curling.  Mr.,  researches  of,  561,  562 


Cuticle,  470 
Cutis,  468 
Cystic  duct,  525 
Cyto-blast,  470 


D. 


Dartos,  540 

Davy,  Dr.,  researches  of,  296 
Derbyshire  neck,  392 
Dennis,  468 
Detrusor  urinas,  533 
Diaphragm,  217 
Diaphysis,  48 
Diarthrosis,  130 
Digital  cavity,  375 
Diverging  fibres,  386 
Dorsi-spinal  veins,  348 
Ductus  ad  nasum,  456 

arteriosus,  553 

comm.  choledochus,  525 

cysticus,  525 

ejaculatorius,  537 

hepaticus,  525 

lymphaticus  dexter,  360 

pancreaticus,  526 

prostaticus,  535 

thoracicus,  360 

venosus,  553 
Duodenum,  506 
Dura  mater,  368 

E. 

Ear,  456 

Ejaculatory  duct,  537 

Elastic  tissue,  135 

Enamel,  94 

Enarthrosis,  131 

Encephalon,  367 

Endplymph,  462 

Ensiform  cartilage,  100 

Entozoon  folliculorum,  474 

Epidermis,  470 

Epididymis,  543 

Epigastric  region,  496 

Epiglottic  gland,  491 

Epiglottis,  486 

Epiglottp-hyoidean  ligament,  488 

Epiphysis,  48 

Epithelium,  511 

Erectile  tissue,  537 

Eustachian  tube,  460 

valve,  478 

Eustachius,  notice  of,  478 
Eye,  445 

brows,  453 

globe,  445 

lashes,  453 

lids,  453 

F. 

Falciform  process,  273 
Fallopian  tubes,  549 
Fallopius,  notice  of,  549 
Falx  cerebelli,  369 

cerebri,  369 
FASCIA. 

general  anatomy  of,  263 

cervical,  deep,  264 
superficial,  264 

cribriform,  272 

dentata,  37^ 


INDEX. 


567 


FASCIA— continued. 

iliaca,  268 

inter-columnar,  212 

lata,  272 

lumbar,  215 

obturator,  269 

palmar,  271 

pelyica,  263 

perineal,  269 

plantar,  274 

propria,  274 

recto-vesical,  269 

spermatica,  212 

temporal,  264 

thoracic,  265 

transversalis,  266 
Fasciculi  innominati,  387 

siliquae,  388 

teretes,  389 
Fauces,  502 
Femoral  arch,  273 

canal,  273 

hernia,  273 

ring,  273 
Fenestra  ovalis,  460 

rotunda,  460 
Fibres  of  the  heart,  483 
Fibro-cartilage,  133 

inter-articular  of  the  clavicle,  150 
jaw,  144 
knee,  161 
wrist,  155 

cellular  tissue,  136 
Fibrous  tissue,  135 
Filum  terminate,  390 
Fimbriae,  Fallopianse,  549 
Fissure  of  Bichat,  361 

Sylvius,  372 

Fissures  of  the  liver,  517 
Flocculus,  381 
Fostal  circulation,  553 
Foetus,  anatomy  of,  552 
Follicles  of  Lieberkuhn,  543 
Fontana,  notice  of,  449 
Foramen  of  Botal,  478 

caecum,  467 

commune  anterius,  381 
posterius,  381 

Monro,  of,  378 

ovale,  553 

saphenum,  273 

Soemmering,  of,  449 

Winslow,  of,  500 
Foramina  Thebesii,  477 
Fornix,  377 
Fossa  innominata,  456 

navicularis  urethras,  537 

pudendi,  551 

ovalis,  478 

scaphoides,  456 
Fourchette,  550 
Fraena  epiglottidis,  467,  488 
Fraenulum  labiorum,  550 

veli  medull.,  380 
Fraenum  labii,  468 

linguae,  467 

praeputii,  536 
Funiculi  siliquae,  386 

graciles,  386 


G. 


Galea  capitis,  174 
Galen,  275 


Gall-bladder,  525 
Ganglia,  cervical,  437 

of  increase,  361 

lumbar,  441 

sacral,  442 

eemilunar,  441 

structure  of,  361 

thoracic,  440 
Ganglion  of  Andersch,  404 

Arnold's,  436 

azygos,  442 

cardiac,  440 

carotid,  439 

Casserian,  396 

ciliary,  433 

Cloquet's,  435 

impar,  442 

jugular,  403 

lenticular,  433 

Meckel's,  435 

naso-palatine,  435 

otic,  436 

petrous,  403 

plexiforme,  404 

Ribes,  of,  433 

spheno-palatine,  435 

submaxillary,  436 

thyroid,  438 

vertebral,  438 
Gimbernat's  ligament,  216 
Ginglymus,  130 
Gland,  epiglottic,  491 

lachrymal,  455 

parotid,  503 

pineal,  379 

pituitary,  384 

prostate,  534 

thymus,  556 

thyroid,  492 
Glands,  aggregate,  513 

arytenoid,  491 

Brunner's,  512 

concatenated,  354 

Cowper's,  540 

duodenal,  512 

gastric,  512 

inguinal,  355 

lachrymal,  455 

Lieberkuhn's,  513 

lymphatic,  358 

mammary,  583 

mesenteric,  361 

Meibomian,  454 

O3sophageal,  512 

Pacchionian,  369 

Peyer'a,  513 

pharyngeal,  512 

salivary,  503 

sebaceous,  474 

solitary,  513 

sublingual,  504 

Bubmaxillary,  503 

sudoriparous,  474 

tracheal,  492 
Glandulae  odoriferae,  5S6 

Pacchioni,  369 

Tysoni,  536 
Glans  clitoridis,  551 

penis,  536 

Glisson,  notice  of,  500 
Glisson's  capsule,  519 
Globus  major-epididymis,  5 

minor  epididymis,  543 
Glottis,  490 


508 


INDEX. 


Goodsir,  Mr.,  researches  of,  95 

Goitre,  392 

Gomphosis,  130 

Graafian  vesicles,  550 

Grainger,  Mr.,  researches  of,  367 

Gubernaculum  testis,  560 

Gums,  502 

Guthrie,  Mr.,  researches  of,  534 

Guthrie's  muscle,  220 

Gyrus  fornicatus,  376 

H. 

Hair,  473 

Hall,  Dr.  Marshall,  researches  of,  367 

Harmonia,  130 

Haversian  canals,  44 

Heart,  475 

Helicine  arteries,  537 

Helico-trema,  464. 

Helix,  456 

Hepatic  duct,  525 

Hernia,  congenital,  267 

diaphragmatic,  217 

direct,  268 

encysted,  267 

femoral,  273 

infantilis,  267 

inguinal,  266 

scrotal,  268 

Highmore,  notice  of,  542 
Hilton's  muscle,  484 
Hilus  lienis,  557 

renalis,  529 
Hippocampus  major,  376 

minor,  376 
Homer's  muscle,  176 
Homer,  W.  E.,  observations  of,  514 
Houston,  Mr.,  researches  of,  511 
Humours  of  the  eye,  451 
Hyaloid  membrane,  451 
Hymen,  551 
Hyoid  bone,  99 
Hypochondriac  regions,  496 
Hypogastric  region,  496 
Hypophysis  cerebri,  384 

I. 

Ileo-caecal  valve,  510 

Ileum,  507 

Iliac  regions,  496 

Incus,  458 

Infundibula,  530 

Infundibulum,  383 

Inguinal  region,  496 

Inter-articular  cartilages  of  the  clavicle,  150 

jaw,  144 

wrist,  155 

Inter-columnar  fibres,  212 
Inter-vertebral  substance,  138 
Intestinal  canal,  501 
Intumescentia  gangliformis,  401 
Iris,  448 

Isthmus  of  the  fauces,  502 
Iter  ad  infundibulum,  379 

a  tertio  ad  quarturh  ventriculum,  379 

J. 

Jacob's  membrane,  450 
Jejunum,  507 
Joint,  ankle,  165 
elbow,  152 


Joint,  hip,  158 

lower  jav ,  145 

knee,  160 

shoulder,  152 

wrist,  155 
Jones,  Mr.,  researches  of,  464 

K. 

Kidneys,  528 

Kiernan,  Mr.,  researches  of,  520 
King,  Mr.  T.  W.,  researches  of,  479 
Krause,  researches  of,  222 

L. 

Labia  majora,  550 

minora,  550 
Labyrinth,  461 
Lachrymal  canals,  455 
gland,  455 
papilla?,  455 
puncta,  455 
sac,  456 
tubercles,  453 
Lacteals,  358 
Lacuna?,  540 
Lacus  lachrymalis,  455 
Lamina  cinerea,  382 
cribrosa,  446 
spiralis,  464 
Laqueus,  388 
Laryngotomy,  487 
Larynx,  485 
Lateral  ventricles,  378 
Lauth,  researches  of,  542 
Lee,  Dr.,  researches  of,  548 
Lens,  451 

Lenticular  ganglion,  433 
Lieberkuhn's  follicles,  513 
Lien  succenturiatus,  528 
Ligament,  135 
LIGAMENTS,  129 

acromio-clavicular,  151 
alar,  141,  162 
ankle,  of  the,  164 
annular,  of  the  ankle,  274 
radius,  153 
wrist,  anterior,  155 

posterior,  271 
arcuatum  externum,  217 

internum,  217 
atlo-axoid,  141 
bladder,  of,  532 
breve  plantae,  166 
calcaneo-astragaloid,  165 
cuboid,  165 
scaphoid,  166 
capsular  of  the  hip,  158 
jaw,  143 
rib,  145 
shoulder,  152 
thumb,  157 
carpal,  156 

carpo-metacarpal,  156 
common  anterior,  138 

posterior,  138 
conoid,  151 
coracoid,  151 
coraco-acromial,  151 
clavicular,  15], 
humeral,  152 
coronary,  154 

of  the  knee,  161 


INDEX. 


563 


LIGAMENTS — continued. 
costo-clavicular,  150 

sternal,  145 

transverse,  145 
vertebral,  144 

xiphoid,  146 
cotyloid,  159 
crico-thyroidean,  487 
crucial,  161 
cruciform,  142 
dentatum,  382 
deltoid,  165 
elbow,  of  the,  152 
epiglotto-hyoidean,  488 
glenoid,  152 
hip  joint,  of  the,  158 
hyo-epiglottic,  487 
ilio-femoral,  159 
inter-articular,  of  ribs,  145 
inter-clavicular,  150 
inter-osseous,  163,  166 

calcaneo-astragal.,  166 

peroneo-tibial,  163 
radio-ulnar,  153 
inter-spinous,  139 
inter-transverse,  140 
inter-vertebral,  138 
knee,  of  the,  160 
lateral  of  the  ankle,  165 

elbow,  153 

jaw,  143 

knee,  160 

phalanges,  foot,  168 

phalanges,  hand,  157 

wrist,  155 
liver,  of  the,  516 
longum  plantae,  166 
lumbo-iliac,  146 
lumbo-sacral,  146 
metacarpo-phalangeal,  157 
metatarsal-phalangeal,  167 
mucosum,  162 
nuchae,  199 
oblique,  154 
obturator,  149 
occipito-atloid,  140 

axoid,  141 
odontoid,  141 
orbicular,  154 
palpebral,  453 
patellae,  160 
peroneo-tibial,  163 
phalanges  of  the  foot,  167 

of  the  hand,  157 
plantar,  long,  166 
plantar,  short,  166 
posticum  Winslowii,  160 
pterygo-maxillary,  142 
pubic,  149 
radio-ulnar,  153 
rhomboid,  150 
rotundum,  hepatis,  516 
sacro-coccygean,  148 
sacro-iliac,  147 
sacro-ischiatic,  anterior,  147 

posterior,  148 
stellate,  144 
sternal,  145,  146 
Bterno-clavicular,  149 
Btylo-maxillary,  265 
sub-flava,  139 
sub-pubic,  149 
supra-spinous,  139 
euspensorium  hepatis,  516 

48* 


IGASIENTS — continued. 

suspensorium  penis,  536 
tarsal,  165 

tarso-metatarsal,  167 
teres,  159 

thyro-arytenoid,  487 
thyro-hyoidean,  487 
tibio-fibular,  163 
transverse,  164 

of  the  acetabulum,  159 
of  the  ankle,  164 
of  the  atlas,  141 
of  the  knee,  159 
of  the  metacarpus,  157 
of  the  metatarsus,  167 
of  the  scapula,  151    ^ 
of  the  semilunar  cartilages,  161 
trapezoid,  151 
tympanum,  of  the,  468 
umbilical,  532 
wrist,  of  the,  155 
Zinn,  of,  177 
Ligamentum  nuchae,  199 
Limbus  luteus,  449 
Linea  alba,  212 
Lineee  semi-lunares,  212 
transversee,  212,  373 
Linguetta  laminosa,  380 
Lips,  502 

Liquor  Cotunnii,  465 
Morgagni,  451 
Scarpa,  of,  466 
Liver,  515 

Lobules  of  the  liver,  519 
Lobuli  testis,  542 
Lobulus  auris,  456 

pneumogastricus,  381 
Lobus  caudatus,  518 
quadratus,  518 
Spigelii,  518 
Locus  niger,  383 

perforatus,  383 
Lower,  notice  of,  478 
Lumbar  fascia,  215 

regions,  496 
Lungs,  492 
Lunula,  472 

Lymphatic  glands  and  vessels,  351 
axillary,  354 
bronchiad,  357 
cardiac,  358 
cervical,  354 
head  and  neck,  353 
heart,  357 
iliac,  357 
inguinal,  355 
intestines,  358,  359 
kidney,  359 
lacteals,  358 
liver,  358 

lower  extremity,  355 
lungs,  357 
mediastinal,  356 
mesenteric,  358 
pelvic  viscera,  359 
popliteal,  355 
spleen,  358 
stomach,  358 
testicle,  359 
trunk,  356 

upper  extremity,  354 
viscera,  357 
Lyra,  377 


57C 


INDEX. 


M. 

Malleus,  458 

Malpighian  bodies,  528,  530 
Mammae,  551 
Mammary  gland,  552 
Mastoid  cells,  460 
Matrix,  546 

Maxillo-pharyngeal  space,  192 
Mayo,  Mr.,  researches  of,  395 
Meatus,  auditorius,  457 

urinarius,  female,  545 

male,  536 

Meatuses  of  the  nares,  444 
Meckel's  ganglion,  435 
Meconium,  559 
Mediastinum,  496 

testis,  542 
Medulla  of  bones,  44 

innominata,  383 

oblongata,  385 
Meibomian  glands,  454 
Meibomius,  notice  of,  454 
Membrana  dentata,  390 

nictitans,  455 

pigmenti,  448 

pupillaris,  555 

sacciformis,  153 

tympani,  458 
Membrane,  choroid,  448 

hyaloid,  451 

Jacob's,  450 

of  the  ventricles,  380 
Membranous  urethra,  539 
Meniscus,  133 
Mesenteric  glands,  358 
Mesentery,  498 
Meso-colon,  498 
Meso-rectum,  499 
Metacarpus,  112 
Metatarsus,  127   ^ 
Milral  valves,  48? 
Modiolus,  463 
Mons  Veneris,  550 
Monticulus  cerebelli,  382 
Morgagni,  notice  of,  451 
Morsus  diaboli,  549 
Motor  tract,  391 
Mouth,  502 

Mucous  membrane,  structure,  5 
Miiller,  researches  of,  45 
MUSCLES,  168 

general  anatomy  of,  168 

development  of,  172 

structure,  169 

abductor  min.  digiti,  240 

abduc.  min.  dig.  pedis,  260 
indicis,  241 
oculi,  177 
pollicis,  238 
pedis,  260 

accelerator  urinae,  220 

accessorjus,  261 

adductor  brevis,  250 
longus,  250 
magnus,  250 
min.  digiti,  260 
oculi,  177 
pollicis,  239 
pedis,  261 

anconeus,  236 

anterior  auris,  185 

auti-tragicus,  45"* 

arytenoideus,  489 


MUSCLES — continued. 

aryteno-epiglot.  inf..  469 

superior,  489 
attollens  aurem,  184 

oculum,  177 
attrahens  aurem,  185 
auricularus,  236 
azygos  uvulae,  195 
basio-glossus,  191 
biceps  flexor  cruris,  251 
cubiti,  229 

biventer  cervicis,  204 
brachialis  anticus,  230 
buccinator,  183 
bulbo-cavernosus,  220 
cerato-glossus,  191 
cervicalis  ascendens,  204 
circumflexus  palati,  195 
coccygeus,  222 
complexus,  204 
compreesor  nasi,  179 

urethras,  220 
constrictor  inferior,  192 

isth.  faucium,  192,  195 

medius,  193 

pharyngis,  192 

superior,  193 

vaginae,  223 
coraco- brachialis,  229 
corrugator  supercilii,  175 
cremaster,  214 
crico-arytenoid  lat.,  488 
ppsticus,  488 

thyroideus,  488 
crureus,  248 
cucullaris,  199 
deltoid,  228 
depressor  ang.  oris,  181 

labii  inferioris,  181 

labii  sup.  alaeque  nasi,  ]81 
depressor  oculi,  177 
detrusor  urinae,  532 
diaphragm,  217 
dilatator  naris,  179 
digastricus,  189 
erector  clitoridis,  551 

penis,  220 

spins,  203 
extensor  carpi  rad.  brev.  235 

carpi  rad.  long.,  235 

carpi  ulnaris,  236 

coccygis,  206 

digiti  minimi,  236 

digitor.  brevis,  258 

digitor.  com.,  235 

digitor.  longus,  253 

indicis,  238 

ossis  metacarpi,  237 

pollicis  proprius,  254 

primi  internodii,  237 

sec.  internodii,  237 
flexor  accessorius,  261 

brevis  digiti  minimi,  240 
digiti  minimi  pedis,  262 

carpi  radialis,  232 
ulnaris,  233 

digitorum  brevis,  260 
profundus,  233 
sublimis,  232 

longus  digit,  pedis,  256 

longus  pollicis  manus,  233 
pedis,  256_ 

ossis  metacarpi,  239,  240 

pollicis  brevis,  239 


INDEX. 


571 


MUSCLES — continued. 
pedis,  261 
longus,  256 
gastrocnemius,  254 
gemellus  inferior,  246 

superior,  245 
genio-hyo-glossus,  190 

hyoideus,  190 
gluteus  maximus,  244 

medius,  244 

minimus,  245 
gracilis,  251 
heiicis  major,  457 

minor,  457 
hyo-glossus,  190 
iliacus,  249 
indicator,  238 
infra-spinatus,  227 
inter-costales  externi,  210 

interni,  210 
interossei  manus,  241 

pedis,  259 
knter-spinales,  205 
mter-transversales,  2t>5 
fntra-costales,  210 
sschio-cavernosus,  230 
larynx,  of  the,  488 
latissimus  dorsi,  199 
laxator  tympani,  459 
levator  anguli  oris,  180 

scapulae,  201 

ani,  222 

glandulae  thyroid.,  O2 

labii  inferioris,  182 
superioris,  180 
sup.  alaeq.  nasi,  It3 

menti,  182 

palati,  194 

palpebrae,  177 
levatores  costarum,  205 
lingualis,  191 
longissimus  dorsi,  203 
longus  colli,  197 
lumbricales  manus,  240 

pedis,  261 
mallei  externus,  459 

internus,  459 
masseter,  182 
multifidus  spinae,  206 
mylo-hyoideus,  190 
myrtiformis,  181 
nasp-labialis,  180 
obliquus  abdom.  ext.,  212 

abdpm.  int.,  214 

capitis  inferior,  205 
superior,  205 

oculi  inr°rior,  178 
superior,  178 
obturator  externus,  246 

internus,  245 
occipito-frontalis,  174 
omo-hyoideus,  188 
opponens  digit,  min.,  240 

pollicis,  239 
orbicularis  oris,  180 

palpebrarum,  175 
palato-glossus,  192,  195 

pharyngeus,  195 
pabnaris  brevis,  240 

longus,  232 
pectineus,  250 
pectoralis  major,  225 

minor,  225 
peroneus  brevis.  258 


MUSCLES — continued. 

longus,  258 

tertms,  254 
plantaris,  255 
platysma-myoides,  186 
popliteus,  256 
posterior  auris,  185 
pronator  quadratus,  234 

radii  teres,  231 
psoas  magnus,  249 

paryus,  216 
pterygoideus  ext.,  183 

int.,  184 
pyramidalis  abdom.,  216 

nasi,  179 
pyriformis,  245 
quadratus  femoris,  246 

lumborum,  216 

menti,  181 
rectus  abdominis,  216 

capitis  ant.  maj.,  196 
i:niin.,  196 

Iatef%lis,  205 

post,  maj.,  205 
min.,  205 

femoris,  248 

oculi  externus,  177 
inferior,  177 
internus,  177 
superior,  177 
retrahens  aurem,  185 
rhombpideus  major,  201 

minor,  201 

risorius  Santprini,  186 
sacro-lumbalis,  203 
sartorius,  247 
scalenus  anticus,  196 

posticus,  197 
Bemi-spinalis  colli,  205 

dorsi,  205 

semi-membranosus,  252 
semi-tendi'.osus,  251 
teerratus  magnus,  226 

posticus  inf.,  202 

sup.,  201 
soleus,  255 
sphincter  ani,  222 

internus,  222 
epinalis  dorsi,  203 
splenius  capitis,  202 

colli,  202 
Btapedius,  459 
eterno-hyoider^  188 

mastpideuj,  186 

thyroideus,  188 
stylo-glpssus,  192 

hyoideus,  189 

pharyngeus,  193 
subclavius,  226 
subcrureus,  248 
subscapularis,  226 
superior  auris,  *84 
supinator  brevis,  237 

longus,  234 
supra-spinalis,  206 
supra- spinatus,  227 
ter-.poral,  182 
tensor  palati,  195 

tarsi,  176 

tympani,  459 

vaginae  fern.,  247 
teres  major,  228 

minor,  227 
thyro-arytenoideus.  483 


572 


INDEX. 


MUSCLES — Continued. 

epiglottideus,  489 
hyoideus,  188 
libialis  anticus,  253 

posticus,  257 
trachelo-mastoideus,  204 
tragicus,  457 
transversalis  abdom.,  215 

colli,  204 

transversus  auris,  457 
pedis,  262 
perinei,  221,  223 
trapezius,  199 
triangularis  oris,  181 

sterni,  211 
triceps  extens.  cruris,  248 

cubiti,  230 
trochlearis,  178 
ureters,  of  the,  533 
vastus  externus,  248 

interims,  248 
zygomaticus  major,  181 

minor,  181 
Muscular  fibre,  169 
Musculi  pectinati,  479 
Myolemma,  169 
Myoline,  171 
Myopia,  451 

N. 

Naboth,  ovula  of,  547 
Nagel,  Mr.,  researches  of,  f  ,8 
Nails,  472 
Nares,  444 
Nasal  duct,  456 

fossa?,  442 

Nasmyth,  Mr.,  researches  of,  94,  511 
Nates  cerebri,  379 
NEXVES. 

general  anatomy,  361 
abducentes,  401 
accessprius,  404 
acromiales,  412 
auditory,  403 
auricularis  anterior,  400 
magnus,  412 
posterior,  402 
brachial,  414 
buccal,  399 
cardiac,  407 
cardiacus  inferior,  438 
magnus,  439 
medius,  438 
minor,  439 
superior,  438 
cervical,  410 
cervico-facial,  403 
chorda  tympani,  402 
ciliary,  398 
circumflex,  420 
claviculares,  412 
coccygeal,  426 
cochlear,  404 
communicans  noni,  412 
peronei,  428 
poplitei,  429 
cranial,  393 
crural,  424 

cutaneous  ext.  brach.,  41» 
ext.  femoralis,  423 
int.  brachialis,  416 

minor,  416 
med  femoralis,  424 


NEBVBS — continued. 

post,  femoralis,  429 

spiralis,  419 
dental  anterior,  399 

inferior,  400 

posterior,  399 
descendens  noni,  409 
digastric,  402 
dorsal,  420 
eighth  pair,  404 
facial,  401 
femoral,  424 
fifth  pair,  396 
first  pair,  393 
fourth  pair,  395 
frontal,  397 
gastric,  407 
genito  crural,  423 
glosso-pharyngeal,  404 
gluteal,  428 

inferior,  428 
gustatory,  400 
hypo-glossal,  408 
ilio-scrotal,  423 
inferior  maxillary,  399 
infra-trochlear,  396 
inguino-cutaneous,  423 
intercostal,  420 
intercosto-humeral,  421 
interosseous  anterior,  417 

posterior,  419 
ischiaticus  major,  429 

minor,  428 
Jacobson's,  404 
lachrymal,  397 
laryngeal  inferior,  407 

superior,  406 
lingual,  396 
lumbar,  422 
lumbo-sacral,  426 
masseteric,  399 
maxillaris  inferior,  399 

superior,  396 
median,  416 
molles,  438 

motores  oculorum,  395 
musculo-cutan.,  arm,  416 

leg,  432 

musculo-spiral,  419 
mylo-hyoidean,  397 
nasal,  397 
naso-ciliaris,  397 

palatine,  435 
ninth  pair,  408 
obturator,  426 
occipitalis  major,  413 

minor,  412 
olfactory,  393 
ophthalmic,  397 
optic,  394 
orbital,  398 
palatine  anterior,  435 

posterior,  435 
palmar,  deep,  417 

superficial,  417 
pathetici,  395 
perforans  Casserii,  416 
perineal,  428 
peroneo-cutaneous,  428 
peroneal,  431 
petrosal,  434 
petfosus  minor,  436 
pharyngeal,  405,  406 
phrenic,  413 


INDEX. 


NERVES — continued. 

plantar,  external,  431 
internal,  431 

pneumogastric,  405 

popliteal,  429 

portio  dura,  401 
moll  is,  403 

pterygoid,  399 

pudendalis,  429 

pudic,  internal,  428 

pulmonary,  407 

radial,  419 

recurrent,  407 

respiratory,  external,  415 

sacral,  426 

saphenous,  external,  430 
long,  425 
short,  425 

second  pair,  394 

seventh  pair,  401 

sixth  pair,  401 

spheno-palatine,  435 

spinal,  409 

spinal  accessory,  408 

splanchnicus  major,  441 
minor,  441 

stylo-hyoid,  403 

subcutaneus  malae,  398 

sub-occipital,  403 

subrufi,  438 

subscapular,  415 

superficialis  colli,  412 
cordis,  438 

superior  maxillary,  398 

snpra-orbital,  396 
scapular,  415 
trochlear,  395 

sympatheticus  major,  433 

temporal,  399 

temporo-facial,  403 
malar,  400 

third  pair,  395 

thoracic,  long,  415 
short,  415 

thyro-hyoidean,  409 

tibialis  anticus,  432 
posticus,  430 

trifacial,  396 

trigeminus,  396 

trochlearis,  395 

tympanic,  402 

ulnar,  418 

vagus,  404 

vestibular,  404 

Vidian,  435 

Wrisberg,  of,  416 
Neurilemma,  361 
Nipple,  552 
Nodulus,  382 
Nodus  encephali,  38o 
Nose,  442 
Nucleus  Qlivse,  386 
Nymphae,  550 

O. 

(Esophagus,  d05 

Omentum,  gastro-splenic,  498 

great,  498 

lesser,  498 

Omphalo-mesenteric  vessels,  559 
Optic  commissure,  393 

thalami,  378 
Orbiculare,  os,  459 


Orbits,  90 

Ossicula  auditus,  458 
Ossification,  49 
Ostium  abdominale,  549 

uterinum,  549 
Otoconites,  466 
Ovaries,  549 
0 vula  Graanana,  550 

Naboth,  of,    47 

P. 

Pacchionian  glands,  371 
Palate,  502 
Palmar  arch,  306 
Palpebrae,  453 
Palpebral  ligaments,  454 

sinuses,  454 
Pancreas,  526 
Panizza,  researches  of,  437 
Papillae  of  the  nail,  472 

of  the  skin,  469 

of  the  tongue,  467 

calyciformes,  467 

circumvallatae,  467 

conicae,  467 

filiformes,  467 

fungiformes,  468 
Parotid  gland,  503 
Pelvis,  117 

viscera  of,  532 
Penis,  536 
Pericardium,  475 
Perichondrium,  46 
Pericranium,  46 
Periosteum,  46 
Peritoneum,  497 
Perspiratory  ducts,  474 
Pes  accessorius,  37 

anserinus,  401 

hippocampi,  376 
Petit,  notice  of,  452 
Peyer,  notice  of,  513 
Peyer's  glands,  513 
Phalanges,  113,  128 
Pharynx,  504 
Pia  mater,  371 
Pigmentum  nigrum,  448 
Pillars  of  the  palate,  503 
Pineal  gland,  379 
Pinna,  456 
Pituitary  gland,  384 

membrane,  445 
Pleurae,  495 
Plexus,  aortic,  441 

axillary,  414 

brachial,  414 

cardiac,  440 

carotid,  436 

cavernosus,  436 

cervical,  anterior,  411 
.posterior,  413 

choroid,  375 

cceliac,  *49 

coronary,  43^ 

gjangliformis,  401 

gastric,  440 

fiepatic,  440 

hypogastric,  442 

lumbar,  419 

mesenteric,  inferior,  441 
superior,  441 

O3sophagf\l,  404 

pharyngeal,  402 


574 


INDEX. 


PLEXUS — continued. 

phrenic,  441 

pros'atic,  340 

pterygoid,  330 

pulmonary,  403,  439 

renal,  441 

sacral,  424 

solar,  441 

spermatic,  441 

splenic,  441 

submaxillary,  397 

supra-renal,  441 

uterine,  341 

yertebral,  437 

vesical,  341 
Plica  semilunaris,  455 
Plicae  longitudinales,  509 
Pneumogastric  lobule,  382 
Polypus  of  the  heart,  476 
Pomum  Adami,  485 
Pons  Tarini,  385 

Varolii,  385,  389 
Pores,  471 
Portal  vein,  349 
Portio  dura,  401 

mollis,  403 
Porus  opticus,  446 
Poupart's  ligament,  212 
Prepuce,  536 
Presbyopia,  452 
Processus  e  cerebello  ad  testes,  383 

clavatus,  386 

vermiformes,  384 
Promontory,  460 
Prostate  gland,  534 
Prostatic  urethra,  538 
Protuberantia  annulaiis,  385 
Pulmonary  artery,  494 

plexuses,  494 

sinuses,  480 

veins,  351 
Puncta  lachrymalia,  455 

vasculosa,  373 
Pupil,  448 

Purkinje,  corpuscles  of,  45 
Pylorus,  506 
Pyramid,  460 
Pyramids,  anterior,  386 

posterior,  380 

of  Wistar,  72 

R. 

Raphe,  corporis  callosi,  373 
Receptaculum  chyli,  359 
Rectum,  533 
Regions,  abdominal,  496 
Ren1,  island  of,  383 
Respiratory  nerves,  495 

tract,  388 
Rete  mucosum,  471 

testis,  543 
Retina,  449 
Ribs,  101 

Ribes,  ganglion  of,  433 
Rima  glottidis,  488 
Ring,  external  abdominal,  212 

femoral,  278 

internal  abdominal,  271 
Rugae,  510,  546 
Ruysch,  notice  of,  449 

S. 
Sacculus  communis,  465        ' 


Sacculus  laryngis,  490 

proprius,  465 
Salivary  glands,  503 
Saphenous  opening,  273 

veins,  344 
Scala  tympani,  463 

vestibuli,  463 
Scarf-skin,  430 
Scarpa,  notice  of,  466 
Schindylesis,  83 
Schneider,  notice  of,  445 
Schneiderian  membrane,  445 
Sclerotic  coat,  445 
Scrotum,  540 

Searle,  Mr.,  researches  of,  483 
Sebaceous  glands,  470 
Semicircular  canals,  452 
Semilunar  nbro-cartilages,  161 

valves,  480 
Septum  auricularum,  478 

crurale,  273 

lucidum,  376,  389 

pectiniforme,  537 

scroll,  540 

Serous  membrane,  structure,  501 
Sesamoid  bones,  129 
Sheath  of  the  rectus,  216 
Sigmoid  valves,  480 
Sinuses,  structure,  337 
Sinus,  aortic,  480 

basilar,  340 

cavernous,  340 

circular,  340 

fourth,  339 

lateral,  339 

longitudinal,  inferior,  339 
superior,  338 

occipital,  anterior,  339 
posterior,  339 

petrosal,  inferior,  340 
superior,  340 

pocularis,  539 

prostatic,  539 

pulmonary,  480 

rectus  or  straight,  339 

rhomboidalis.  379 

transverse,  341 

Valsalva,  of,  480 
Skeleton,  49 
Skin,  468 
Skull,  58 

Socia  parotidis,  503 
Simmering,  notice  of,  450 
Soft  palate,  502 
Spermatic  canal,  271 

cord,  540 

Spheno-palatine  ganglion,  435 
Spigel,  notice  of,  518 
Spinal  cord,  389 

nerves,  409 

veins,  348 
Spleen,  526 

Spongy  part  of  the  urethra,  539 
Stapes,  458 
Stenon,  notice  of,  503 
Stenon's  duct,  503 
Stomach,  505 
Striae,  medullares,  376 

muscular,  169 
Sub-arachnoidean  fluid,  371 

space,  371 

tissue,  372 

Sublingual  gland,  504 
Submaxillary  gland,  503 


INDEX. 


Substantia,  cinerea,  372 

perforata,  383. 
Sudoriferous  ducts,  471 
Sudoriparous  glands,  471 
Sulcus  hepatis,  518 

longitudinal  cordae  spinal.,  391 
Supercilia,  453 
Superficial  fascia,  264 
Supra-renal  capsules,  527 
Suspensory  ligament,  liver,  516 

penis,  536 
Sutures,  83 
Sylvius,  notice  of,  372 
Sympathetic  nerve,  438 
Symphysis,  130 
Synarthrosis,  130 
Synovia,  137 
Synovial  membrane,  136 

T. 

Tapetum,  449 

Tarin,  Peter,  notice  of,  374 

Tarsal  cartilages,  453 

Tarsus,  124 

Teeth,  92 

Tendo  Achillis,  254 

oculi,  175 
Tendon,  169 
Tenia  hippocampi,  376 

semicircularis,  374 

Tarini,  374 

Tentorium  cerebelli,  t€9 
Testes  cerebri,  379 
Testicles,  540 

descent,  561 
Thalami  optici,  378 
Thebesius,  notice  of,  <"YJ 
Theca  vertebralis,  33£ 
Thoracic  duct,  359 
Thorax,  475 
Thymus  gland,  556 
Thyro-hyoid  membrane,  457 
Thyroid  axis,  298 

cartilage,  485 

gland,  492 

Tod,  Mr.,  researches  of,  457 
Tongue,  467 
Tonsils,  503 

cerebelli,  381 
Torcular  Herophili,  339 
Toynbee,  Mr.,  researches  of,  530 
Trachea,  491 
Tractus  motorius,  391 

opticus,  390 

spiralis,  463 
Tragus,  456 

Triangles  of  the  neck,  188 
Tricuspid  valves,  479 
Trigone  vesicale,  534 
Trochlearis,  178 
Tuber  cinereum,  385 
Tubercula  quadrigemina,  380 
Tuberculum  Loweri,  478 
Tubuli  lactiferi,  552 

seminiferi,  542 

uriniferi,  529 

Tunica  albuginea  oculi,  445 
testis,  542 

erythroides,  541 

nervea,  446 

Ruyschiana,  449 

vaginalis,  542 
oculi,  445 


Tunica  vasculosa  testis,  542 
Tutamina  oculi,  453 
Tympanum,  458 
Tyrrell,  Mr.,  researches  of,  268 
Tyson's  glands,  536 

U. 

Umbilical  region,  496 
Urachus,  532 
Ureter,  530 
Urethra,  female,  544 

male,  537 
Uterus,  546 

Utriculus  communis,  465 
Uvea,  447 
Uvula  cerebelli,  382 

palati,  503 

vesicae,  534 

V. 

Vagina,  545 
Vallecula,  371 
Valsalva,  sinuses  of,  480 
Valve,  arachnoid,  370 

Bauhini,  510 

coronary,  478 

Eustachian,  478 

ileo-caecal,  510 

mitral,  481 

pyloric,  510 

rectum,  of  the,  511 

semilunar,  480 

Tarin,  of,  372 

tricuspid,  478 

Vieussens,  of,  370 
Valvute  conniventes,  510 
Varolius,  notice  of,  385 
Vasa  eflferentia,  543 

lactea,  358 

lymphatica,  357 

pompiniformia,  543 

recta,  543 

vasorum,  281 
Vasculum,  aberrans,  543 
Vas  deferens,  540 
VEINS,  334 

structure,  335 

angular,  337 

auricular,  337 

axillary,  343 

azygos  major,  348 
minor,  348 

basilic,  342 

cardiac,  349 

cava,  inferior,  346 
superior,  345 

cephalic,  343 

cerebellar,  338 

cerebral,  338 

coronary,  349 

corpora,  striata,  374 

diploe,  337 

dorsalis  pern's,  348 

dorsi-spinal,  348 

emulgent,  347 

facial,  336 

femoral,  344 

frontal,  336 

Galeni,  338,  377 

gastric,  350 

hepatic,  "348 

iliac,  345 


576 

V  SINS — continued. 
innominata,  345 
intercostal,  superior,  348 
jugular,  341 
lumbar,  347 
mastoid,  337 
maxillary,  internal,  337 
median,  343 

basilic,  343 

cephalic,  343 
medulli-spinal,  349 
meningo-rachidian,  342,  348 
mesenteric,  inferior,  349 

superior,  349 
occipital,  337 
ovarian,  347 
parietal,  339 
popliteal,  344 
portal,  349 

profunda  femoris,  344 
prostatic,  346 
pulmonary,  351,  495 
radial,  343 
renal,  347 
salvatella,  342 
eaphenous,  external,  344 

internal,  344 
spermatic,  347 
spinal,  348 
splenic,  350 
subclavian,  343 
temporal,  337 
temporo-maxillary,  337 
Thebesii,  349 
thyroid,  342 
ulnar,  342 
uterine,  346 
vertebral,  341,  348 
vesical,  346 

Velum  interpositum,  377 
medullare,  380 
pendulum  palati,  503 


INDEX. 


Vense  comites,  339 

Galeni,  378 

vorticosse,  448 
Ventricle  of  Arantius,  380 
Ventricles  of  the  brain,  378 

fifth,  376 

fourth,  379 

lateral,  373 

third,  377 

of  the  heart,  479,  481 

of  the  larynx,  490 
Vermiform  process,  382 
Vertebral  aponeurosis,  200 

column,  50 
Veru  montanum,  539 
Vesiculae  seminales,  535 
Vestibule,  462 
Vestibulum  vagina?,  551 
Vibrissae,  453 

Vidius,Vidus,  notice  of,  435 
Vieussens,  notice  of,  380 
Villi,  512 

Vitreous  humour,  451 
Vulva,  550 

W 

Wharton,  notice  of,  468 
Wharton's  duct,  504 
Willis,  notice  of,  368 
Wilson's  muscles,  220 
Winslow,  notice  of,  «¥) 
Wistar,  pyramids  of,  73 
Wrisberg,  nerve  of,  416 


Zinn,  notice  of,  450 
Zonula  ciliaris,  450 

of  Zinn,  450 
Zygoma,  64 


CATALOGUE 

OF 

BLANCHARD  &  LEA'S 
MEDICAL  AND  SURGICAL  PUBLICATIONS. 


TO   THE    MEDICAL   PROFESSION. 

In  submitting  the  following  catalogue  of  our  publications  in  medicine  and  the 
collateral  sciences,  we  beg  to  remark  that  no  exertions  are  spared  to  render  the  issues 
of  our  press  worthy  a  continuance  of  the  confidence  which  they  have  thus  far  enjoyed, 
both  as  regards  the  high  character  of  the  works  themselves,  and  in  respect  to  every 
point  of  typographical  accuracy,  and  mechanical  and  artistical  execution.  Gentlemen 
desirous  of  adding  to  their  libraries  from  our  list,  can  in  almost  all  cases  procure  the 
works  they  wish  from  the  nearest  bookseller,  who  can  readily  order  any  which 
may  not  be  on  hand;  and  who,  as  well  as  ourselves,  will  be  happy  to  answer  any 
inquiries  as  to  price,  &c. 

BLANCHARD  &  LEA. 

PHILADELPHIA,  September,  1855. 


TWO  MEDICAL  PERIODICALS,  FREE  OF  POSTAGE, 

FOR  FIVE  DOLLARS  PER  ANNUM. 


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postage,  when  not  paid  for  in  advance,         -        -        -        -        -        -        -    $5  00 

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THE  AMERICAN  JOURNAL  OF  THE  MEDICAL  SCIENCES, 

EDITED  BY  ISAAC  HAYS,  M.  D., 

is  published  Quarterly,  on  the  first  of  January,  April,  July,  and  October.  Each  number  contain* 
at  least  two  hundred  and  eighty  large  octavo  pages,  handsomely  and  appropriately  illustrated, 
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ORIGINAL    COMMUNICATIONS 

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BLANCHARD   &    LEA'S    MEDICAL 


QUARTERLY  SUMMARY, 

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This  department  of  the  Journal,  so  important  to  the  practising-  physician,  is  the  object  of  especial 
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editor  complete  materials  for  this,  purpose,  as  he  not  only  regularly  receives 

ALL  THE  AMERICAN  MEDICAL  AND  SCIENTIFIC  PERIODICALS, 

but  also  twenty  or  thirty  of  the  more  important  Journals  issued  in  Great  Britain  and  on  the  Conti- 
nent, thus  enabling  him  to  present  in  a  convenient  compass  a  thorough  and  complete  abstract  of 
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An  evidence  of  the  success  which  has  attended  these  efforts  may  be  found  in  the  constant  and 
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By  reference  to  the  terms  it  will  be  seen  that,  in  addition  to  this  large  amount  of  valuable  and 
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THE  MEDICAL  NEWS  AND  LIBRARY, 

a  monthly  periodical  of  thirty-two  large  octavo  pages.  Its  "  NKWS  DEPARTMENT"  presents  the 
current  information  of  the  day,  while  the  "LIBRARY  DEPARTMENT"  is  devoted  to  presenting-  stand- 
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without  expense,  the  following  works  which  have  passed  through  its  columns  : — 

WATSON'S  LECTURES  ON  THE  PRACTICE  OF  PHYSIC. 

BRODIE'S  CLINICAL  LECTURES  ON  SURGERY. 

TODD  AND  BOWMAN'S  PHYSIOLOGICAL  ANATOMY  AND  PHYSIOLOGY  OF  MAH. 

724  pages,  with  numerous  wood-cuts,  being  all  that  has  yet  appeared  in  England. 
WEST'S  LECTURES  ON  THE  DISEASES  OF  INFANCY  AND  CHILDHOOD. 
MALGAIGNE'S  OPERATIVE  SURGERY,  with  wood-cuts. 
SIMON'S  LECTURES  ON  GENERAL  PATHOLOGY. 
BENNETT  ON  PULMONARY  TUBERCULOSIS,  with  wood-cuts,  and 
WEST  ON  ULCERATION  OF  THE  OS  UTERI. 

While  the  year  1855,  presents 
BROWN    ON    THE  SURGICAL    DISEASES   OF    FEMALES. 

HANDSOMELY    ILLUSTRATED   ON   WOOD. 

The  diseases  treated  in  this  volume  have  hitherto  not  received  from  writers  of  systematic 
works  the  atteniion  to  which  their  importance  entitles  them.  In  trealises  on  female  diseases  they 
have  been  but  little  noticed,  as  belonging  more  properly  to  the  surgeon,  while  our  surgical  text-books 
have  in  like  manner  referred  them  to  the  writer  on  midwifery  and  female  affections.  In  supplying 
this  palpable  vacancy  in  medioul  literature,  Mr.  Brown  has  brought  to  his  subject  the  result  of 
many  years  of  observation  and  experience,  and  his  labors  will  prove  of  much  value  to  all  practi- 
tioners. The  publishers  therefore  (latter  themselves  that  in  securing  this  volume  for  the  ''  LIBRARY 
DEPARTMENT"  of  ihe  "  MEDICAL  NEWS"  they  will  meet  the  wishes  of  their  numerous  subscri- 
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As  tli-  YFetiieal  News  and  Library  is  in  no  case  sent  without  advance  payment,  its  subscriber* 
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h  >hc  n  (1  ulv)  be  borne  in  mind  that  the  publishers  will  now  take  the  risk  of  remittances  by  mail, 
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July  1,  W>. 

Address  BLANCHARD  &  LEA,  PHILADELPHIA. 


AND    SCIENTIFIC    PUBLICATIONS. 


ALLEN    (J.    M.),    M.  D., 
Professor  of  Anatomy  in  the  Pennsylvania  Medical  College,  &c. 

THE  PRACTICAL  ANATOMIST;  or,  The  Student's  Guide  iii  the  Dissecting. 

ROOM.  With  numerous  illustrations.  In  one  handsome  royal  12mo.  volume.  (In  Press.) 
In  the  arrangement  of  this  work  the  author  has  endeavored  to  present  a  complete  and  thorough 
course  of  dissections  in  a  clearer  and  more  available  form  lor  practical  use  in  the  dissecting-room, 
than  has  as  yet  been  accomplished.  His  long  experience  as  a  teacher  of  anatomy  has  given  him  a 
familiarity  with  the  wants  of  students,  and  has  shown  him  the  best  modes  of  obviating  or  relieving 
the  difficulties  which  present  themselves  in  the  progress  of  dissection.  As  adapted  to  the  cour.-e 
pursued  in  our  colleges,  and  containing  ample  practical  directions  and  instructions,  in  addition  to 
the  anatomical  details  presented,  it  possesses  claims  to  the  immediate  attention  of  teachers  and 
students.  It  will  appear  in  time  for  the  Fall  se.-sion  of  the  present  year. 


ANALYTICAL    COMPENDIUM 

OF  MEDICAL  SCIENCE,  containing  Anatomy,  Physiology,  Surgery,  Midwifery, 
Chemistry,  Materia  Medica,  Therapeutics,  and  Practice  of  Medicine.  By  JOHN  NEILL,  M.  D.. 
and  F.  G  SMITH,  M.  D.  Second  and  enlarged  edition,  one  thick  volume  royal  12mo.  of  over 
1000  pages,  with  350  illustrations.  l3jT  See  NEILL. 


ABEL   (F.    A.),    F.  C.  S. 

Professor  of  Chemistry  in  the  Royal  Military  Academy,  Woolwich. 
AND 

C.    L.    BLOXAM, 

Formerly  First  Assistant  at  the  Royal  College  of  Chemistry. 

HANDBOOK  OF  CHEMISTRY,  Theoretical,  Practical,  and  Technical,  with  a 

Recommendatory  Preface  by  Dr.  HOF.MA.NN.     In  one  large  octavo  volume  of  602  pages,  with 

illustrations.     (Just  Issued.) 

It  must  be  understood  that  this  is  a  work  fitted  for  '  cessary,  with  such  manipulatory  details  as  rendered 
the  earnest  student,  who  resolves  to  pursue  for  him-  i  Faraday's  «  Chemical  Manipulations'  so  valuable  at 
self  a  steady  search  into  the  chemical  mysteries  of  the  time  of  its  publication.  Beyond  this,  the  im- 
creation.  For  such  a  student  the  '  Handbook'  will  •  portanee  of  the  work  is  increased  by  the  introduc- 
prove  an  excellent  guide,  since  he  will  find  in  it,  |  tion  of  much  of  the  technical  chemistry  of  the  manu- 
not  merely  the  approved  modes  of  analytical  investi-  j  factory." — Dr.  Hofmanri's  Preface. 
gation,  but  most  descriptions  of  the  apparatus  ne-  \ 


ASHWELL    (SAMUEL),   M.  D., 

Obstetric  Phj  sifian  and  Lecturer  to  Guy's  Hospital,  London. 

A  PRACTICAL  TREATISE  ON  THE  DISEASES  PECULIAR  TO  WOMEN. 

Illustrated  by  Cases  derived  from  Hospital  and  Private  Practice.  Third  American,  from  the  Third 

and  revised  London  edition.     In  one  octavo  volume,  of  528  pages.    (Now  Ready.) 

The  most ;  useful  practical  work  on  the  subject  in    book   which   shows   so  much   patient  observation, 


the  English  language.  —  Boston  Med.  find  Kurg. 
Journal. 

The  most  able,  and  certainly  the  most  standard 
and  practical,  work  on  female  diseases  that  we  have 
yet  seen. — Medico-Chirurgical  Review. 

We  commend  it  to  our  readers  as  the  best  practi- 
tical  treatise  on  the  subject  which  has  yet  appeared 
— London  Lancet. 

The  young  practitioner  will  find  it  invaluable, 
while  those  who  have  had  most  experience  will  yet 
find  something  to  learn,  and  much  to  commend,  in  a 


practical  skill,  and  sound  sense. — British  and  Fo- 
reign Med.  Review. 

With  no  work  are  we  acquainted,  in  which  the 
pleasant  and  the  useful  are  more  happily  blended.  It 
combines  the  greatest  elegance  of  style  with  the 
most  sound  and  valuable  practical  information. 
We  feel  justified  in  recommending  it,  in  unqualified 
terms,  to  our  readers,  as  a  boo£  from  which  they 
can  scarcely  fail  to  derive  both  pleasure  and  im- 
provement. It  is  truly  a  model  for  medical  compo- 
sitions.— Southern  Med.  and  Surg.  Journal. 


ARNOTT   (NEILL),  M.  D. 
ELEMENTS    OF    PHYSICS;    or  Natural  Philosophy,  General  nnd  Medical. 

Written  for  universal  use,  in  plain  or  non-technical  language.    A  new  edition,  by  ISAAC  HAYS. 
M.  U.     Complete  in  one  octavo  volume,  of  484  pages,  with  about  two  hundred  illustrations. 


BENNETT   (HENRY),  M.  D. 
A  PRACTICAL   TREATISE    ON  INFLAMMATION  OF  THE  UTERUS, 

ITS  CERVIX  AND   APPENDAGES,  and  on  its  connection  with  Uterine  Disease.     Fourth 
'American,  from  the  third  and  revised  London  edition.     In  one  neat  octavo  volume,  of  430  pages, 

with  wood-cuts.      Just  Issued.) 

This  edition  will  be  found  materially  improved  over  its  predecessors,  the  author  having  carefully 
revised  it,  and  made  considerable  additions,  amounting  to  about  seventy-five  pages. 

This  edition  has  been  carefully  revised  and  altered,  When,  a  few  years  back,  the  first  edition  of  the 
and  various  additions  have  been  made,  which  render  present  work  was  published,  the1  subject  was  one  al- 
it  more  complete,  and,  if  possible,  more  worthy  of  most  entirely  unknown  to  the  obstetrical  celebrities 
the  high  appreciation  in  which  it  is  held  by  the  of  the  day  ;  and  even  now  we  have  reason  to  know 
medical  profession  throughout  the  world.  A  copy  that  the  bulk  of  the  profession  are  not  fully  alive  to 
should  be  in  the  possession  of  every  physician. —  the  importance  and  frequency  of  the  disease  of  which 
Charleston  Med.  Journal  and  Review.  it  takes  cognizance.  The  present  edition  is,  so  much 

We  are  firmly  of  opinion  that  in  proportion  as  n    enlarged    nlternd,  and  improved,  that  it  can  scarcely 
knowledge  of  uterine  diseases  becomes  more  appre-    l]  •  considered  the  same  work.— Dr.  banking's  At>- 
ciated,  tiiis  work  will  be  proportionably  established    strnct. 
as  a  text-book  in  the  profession. — The  Lancet, 


BLANCHARD   &    LEA'S   MEDICAL 


BROWN    (ISAAC    BAKER), 

Surgeon-  Accoucheur  to  St.  Mary's  Hospital,  &c. 

OX  SOME  DISEASES  OF  WOMEN  ADMITTING  OP  SURGICAL  TREAT- 

MENT.    Wilh  handsome  illustrations.     Onevol.Svo.     (At  Press.) 

Publishing  in  the  "Medical  News  and  Library"  for  1S')5.     See  preceding  page. 
Mr.  Brown  has  earned  for  himself  a  high  reputa-  !  and  merit  the  careful  attention   of  every   surgeon- 
tion  in  the  operative  trentntent  of  sundry  diseases  ;  accoucheur.  —  Association  Journal. 

Mta-aa 


BENNETT   (J.    HUGHES),    M.D.,    F.  R.  S.  E., 

Professor  of  Clinical  Medicine  in  the  University  of  Edinburgh,  &c. 

THE  PATHOLOGY  AND  TREATMENT  OP  PULMONARY  TUBERCU- 

LOSIS, and  on  the  Local  Medication  of  Pharyngeal  and  Laryngeal  Diseases  frequently  mistaken 
for  or  associated  with,  Phthisis.  In  one  handsome  octavo  volume,  with  beautiful  wood-cuts. 
pp.  130.  (Lately  Issued.) 

BILLING    (ARCHIBALD),  M.  D. 
THE  PRINCIPLES  OP  MEDICINE.     Second  American,  from  the  Fifth  and 

Improved  London  edition.     In  one  handsome  octavo  volume,  extra  cloth,  250  pages. 


BLAKISTON    (PEYTON),  M.  D.,  F.  R.  S.,  &c. 
PRACTICAL    OBSERVATIONS    ON    CERTAIN    DISEASES    OF    THE 

CHEST,  and  on  the  Principles  of  Auscultation.    In  one  volume,  8vo.,  pp.  384. 


BURROWS   (GEORGE),  M.  D. 
ON  DISORDERS  OF  THE  CEREBRAL   CIRCULATION,  and  on  the  Con- 

nection  between  the  Affections  of  the  Brain  and  Diseases  of  the  Heart.     In  one  8vo.  Vol.,  with 
colored  plates,  pp.  21t>. 

BUDD  (GEORGE),  M.  D.,  F.  R.  S., 

Professor  of  Medicine  in  King's  College,  London. 

ON   DISEASES   OF  THE   LIVER.     Second  American,  from  the  second  and 

enlarged  London  edition.     In  one  very  handsome  octavo  volume,  with  four  beautifully  colored 
plates,  and  numerous  wood-cuts,     pp.  468.     New  edition.     (Lately  Issued.) 


The  full  digest  we  have  given  of  the  new  matter 
introduced  into  the  present  volume,  is  evidence  of 
»he  value  we  place  on  it.  The  fact  that  the  profes- 
sion has  required  a  second  edition  of  a  monograph 
such  as  that  before  us,  bears  honorable  testimony 
to  its  usefulness.  For  many  years,  Dr.  Budd's 


work  must  be  the  authority  of  the  sreat  mass  of 
British  practitioners  on  the  hepatic  diseases  ;  and  it 
is  satisfactory  that  the  subject  has  been  taken  up  by 
so  able  and  experienced  a  physician. — Brilisk  and 
Foreign  Medico-Chirurgical  Review. 


BUSHNAN   (J.  S.),    M.  D. 
THE  PHYSIOLOGY  OF   ANIMAL  AND  VEGETABLE  LIFE;  a  Popular 

Treatise  on  the  Functions  and  Phenomena  of  Organic  Life.  To  which  is  prefixed  a  Brief  Expo- 
sition of  the  great  departments  of  Human  Knowledge.  In  one  handsome  royal  12ino.  volume, 
with  over  one  hundred  illustrations,  pp.  234. 

Though  cast  in  a  popular  form  and  manner,  this  work  is  the  production  of  a  man  of  science,  and 
presents  its  subject  in  its  latest  development,  based  on  truly  scientific  and  accurate  principle!*. 
It  may  therefore  be  consulted  with  interest  by  those  who  wish  to  obtain  in  a  concise  form,  and  at 
a  very  low  price,  a  resume  of  the  present  state  of  animal  and  vegetable  physiology. 

BIRD  (GOLDING),  A.  M.,  M .  D.,  &c. 
URINARY     DEPOSITS:     THEIR     DIAGNOSIS,    PATHOLOGY,    AND 

THERAPEUTICAL  INDICATIONS.  A  new  and  enlarged  American,  from  the  last  improved 
London  edition.  With  over  sixty  illustrations.  In  one  royal  12mo.  volume,  extra  cloth,  pp.  372. 


The  new  edition  of  Dr.  Bird's  work,  though  not 
increased  in  size,  has  been  greatly  modified,  and 
much  of  it  rewritten.  It  now  presents,  in  a  com- 
pendious form,  the  gist  of  all  that  is  known  and  re- 
liable in  this  department.  From  its  terse  style  and 
convenient  sine,  it  is  particularly  applicable  to  the 
student,  to  whom  we  cordially  commend  it. — The 
Medical  Examiner. 

It  can  scarcely  be  necessary  for  us  to  say  anything 
of  the  merits  of  this  well-Known  Treatise,  which  so 
admirably  brings  into  practical  application  the  re- 


suits of  those  microscopical  and  chemical  researches 
regarding  the  physiology  and  pathology  of  the  uri- 
nary secretion,  which  have  contributed  so  much  W> 
the  increase  of  our  diagnostic  powers,  and  to  the 
extension  and  satisfactory  employment  of  our  thera- 
peutic resources.  In  the  preparation  of  this  nevr 
edition  of  his  work,  it  is  obvious  that  Dr.  Golding 
Bird  has  spared  no  pains  to  render  it  a  faithful  repre- 
sentation of  the  present  state  of  scientific  knowledge 
on  the  subject  it  embraces.—  The.  British  and  Foreign 
Medico-Ckirttrgical  Review. 


BY   THE  SAME   ATJTHOR. 

ELEMENTS  OF  NATURAL  PHILOSOPHY;   being  an  Experimental  Intro- 

duct  ion  to  the  Physical  Sciences.     Illustrated  with  nearly  four  hundred  wood-cuts.     From  the 
third  London  edition.     In  one  neat  volume,  royal  12mo.     pp.  402. 


AND    SCIENTIFIC    PUBLICATIONS. 


BARTLETT  (ELISHA),  M.  D., 

Professor  of  Materia  Medica  and  Medical  Jurisprudence  in  the  College  of  Physicians  and 
Surgeons,  New  York. 

THE   HISTORY,  DIAGNOSIS,   AND  TREATMENT  OP  THE   FEVERS 

OF  THE  UNITED  STATES.     Third  edition,  revised  and  improved.     In  one  octavo  volume, 
of  six  hundred  pages,  beautifully  printed,  and  strongly  bound. 


The  masterly  and  elegant  treatise,  by  Dr.  Bartlett 
is  invaluable  to  the  American  student  and  practi- 
tioner.— Dr.  Holmes's  Report  to  tke  Nat.  Med.  Asso- 
ciation. 

We  regard  it,  from  the  examination  we  have  made 
of  it,  the  best  work  on  fevers  extant  in  our  language, 
and  as  such  cordially  recommend  it  to  the  medical 
public. — St.  Louis  Medical  and  Surgical  Journal. 

Take  it  altogether,  it  is  the  most  complete  history 
of  our  fevers  which  has  yet  been  published,  and 


Of  the  value  and  importance  of  such  a  work,  it  is 
needless  here  to  speak ;  the  profession  of  the  United 
States  owe  much  to  the  author  for  the  very  able 
volume  which  he  has  presented  to  them,  and  tor  the 
careful  and  judicious  manner  in  which  he  has  exe- 
cuted his  task.  No  one  volume  with  which  we  are 
acquainted  contains  so  complete  a  history  of  our 
fevers  as  this.  To  l)r.  Bartlett  we  owe  our  best 
thiinks  for  tlie  very  able  volume  he  has  given  us.  as 
embodying  certainly  the  most  complete,  methodical, 
and  satisfactory  account  of  our  fevers  anywhere  to 


every  practitioner  should  avail  himself  of  its  coil-  j  be   met  with.—  The  Charleston  Med.  Journal  and 
tents. — The  Western  Lancet.  I  Review. 


BUCKLER  (T.  H.),  M.  D., 

Formerly  Physician  to  the  Baltimore  Almshouse  Infirmary,  &c. 

ON  THE  ETIOLOGY,  PATHOLOGY,  AND  TREATMENT  OF   FIBRO- 

BRONCHITIS  AND  RHEUMATIC  PNEUMONIA.    In  one  handsome  octavo  volume,  extra 
cloth,     pp.  150. 

BOWMAN  (JOHN   E.),  M.D. 
PRACTICAL   HANDBOOK    OF    MEDICAL    CHEMISTRY.     la  one  neat 

volume,  royal  12mo.,  with  numerous  illustrations,     pp.  288. 

BY  THE  SAME  AUTHOR. 

INTRODUCTION    TO    PRACTICAL    CHEMISTRY,    INCLUDING    ANA- 

LYSIS.     With  numerous  illustrations.     In  one  neat  volume,  royal  12mo.     pp.  350. 


BARLOW   (GEORGE  H.),    M.D. 
A  MANUAL  OF  THE  PRINCIPLES  AND   PRACTICE  OF  MEDICINE. 

With  Notes  and  Additions  by  the  American  Editor.     In  one  octavo  volume.     (In  press.) 

BEALE  (LIONEL   JOH  N),  M.  R.  C.  S.,  &c. 
THE   LAWS   OF    HEALTH   IN   RELATION   TO    MIND    AND   BODY. 

A  Series  of  Letters  from  an  old  Practitioner  to  a  Patient.     In  one  handsome  volume,  royal  12mo., 
extra  cloth,     pp.  296. 

BLOOD  AND   URINE  (MANUALS  ON). 
BY  JOHN  WILLIAM   GRIFFITH,  G.  OWEN  REESE,   AND  ALFRED 

MARKWICK.     One  thick  volume,  royal  12mo.,  extra  cloth,  with  plates,     pp.  460. 


BRODIE  (SIR  BENJAMIN   C.),  M.  D.,  &c. 
CLINICAL  LECTURES  ON  SURGERY.     1  vol.  8vo.,  cloth.     350  pp. 


COLOMBAT  DE   L'ISERE. 
A  TREATISE   ON   THE    DISEASES    OF   FEMALES,  and  on  the  Special 

Hygiene  ol  their  Sex.  Translated,  with  many  Notes  and  Additions,  by  C.  D.  MEIGS,  M.  D. 
Second  edition,  revised  and  improved.  In  one  large  volume,  octavo,  with  numerous  wood-cuts, 
pp.  720. 


The  treatise  of  M.  Colombat  is  a  learned  and  la- 
borious commentary  on  these  discuses,  indicating 
very  considerable  research,  great  accuracy  of  judg- 
ment, and  no  inconsiderable  personal  experience. 
With  the  copious  notes  and  additions  of  its  experi- 


enced and  very  erudite  translator  and  editor,  Dr. 
Meigs,  it  presents,  probably,  one  of  the  most  com- 
plete and  comprehensive  works  on  the  subject  we 
possess. — American  Med.  Journal. 


CURLING    (T.    B.),    F.  R.S., 
Surgeon  to  the  London  Hospital,  ice. 

A  PRACTICAL  TREATISE  ON  DISEASES  OF  THE  TESTIS,  SPERMA- 
TIC CORD,  AND  SCROTUM.     Second  American,  from  the  second  and  enlarged  English  edi- 
tion.    In  one  handsome  octavo  volume,  with  numerous  illustrations.     (At  Press.) 
The  additions  of  the  author  will  be  found  to  bring  this  work  on  a  level  with  the  improvements  ol 

Ihe  day,  and  to  maintain  its  reputation  as  the  standard  practical  treatise  on  thte  subject. 


COPLAND  (JAMES),  M.  D.,  F.  R.  S.,  &c. 
OF  THE  CAUSES,  NATURE,  AND  TREATMENT  OF  PALSY  AND 

APOPLEXY,  and  of  the  Forms,  Seats,  Complications,  and  Morbid  Relations  of  Paralytic  and 
Apoplectic  Diseases.     In  one  voltimej  royal  12mo.,  extra  cloth,     pp.  326. 


BLANCHARD  &  LEA'S   MEDICAL 


CARPENTER  (WILLIAM    B.),   M.  D.,  F.'R.  S.,  &.C., 

Examiner  in  Physiology  and  Comparative  Anatomy  in  the  University  of  London. 

PRINCIPLES  OF  HUMAN  PHYSIOLOGY;  with  their  chief  applications  to 

JVycholo^y,  Pathology,  Therapeutics,  Hygiene,  and  Forensic  Medicine.  A  new  American,  from 
the  last  and  revised  London  edition.  With  about  three  hundred  illustrations.  Edited,  with  addi- 
tions, by  FRANCIS  GURNEY  SMITH,  M.  D..  Professor  of  the  Institutes  of  Medicine  in  the  Pennsyl- 
vania Medical  College,  &c.  In  one  very  large  and  beautiful  octavo  volume,  of  about  one  thousand 
large  piiges,  hanilsomely  printed  and  strongly  bound  in  leather,  with  raised  bands.  (Lately  Issued.} 

The  most  complete  work  on  the  science  in  our  |      The  best  text-book  in  the  language  on   this  ex- 
language.— Am.  Med.  Journal.  j  tensive  subject.— London  Med.  Times. 

The  most  complete  exposition  of  physiology  which        *  complete  cyclopaedia  of  this  branch  of  science, 
any  language  can  at  present  give. — Brit,  and  For. 
Med.-Chirurg.  Review.  * 

'\}re  have  thus  adverted  to  some  of  the   leading 


— N.  Y.  Med.  Times. 

The  standard  of  authority  on  physiological  sub- 
jects. *  *  *  In  the  present  edition,  to  particularize 
the  alterations  and  additions  which  have  been  made, 


"additions  and  alterations,"  which  have  been  in-  j  would  require  a  review  of  the  whole  work,  since 
troduced  by  the  author  into  this  edition  of  his  phy-  i  scarcely  a  subject  has  not  been  revised  and  altered, 
siology.  These  will  be  found,  however,  very  far  to  added  to,  or  entirely  remodelled  to  adapt  it  to  the 
exceed  the  ordinary  limits  of  a  new  edition,  "  the  :  present  state  of  the  science. — CharlestonMed.Journ. 
old  materials  having  been  incorporated  with  the 


new,  rather  than  the  new  with  the  old."  It  now 
certainly  presents  the  most  complete  treatise  on  the 
subject  within  the  reach  of  the  American  reader; 
and  while,  for  availability  as  a  text-book,  we  may 
perhaps  regret  its  growth  in  bulk,  we  are  sure  that 
the  student  of  physiology  will  feel  the  impossibility 
of  presenting  a  thorough  digest  of  the  facts  of  the 


The  greatest,  the  most  reliable,  and  the  best  book 
on  the  subject  which  we  know  of  in  the  English 
language. — Stethoscope. 

The  most  complete  work  now  extant  in  our  lan- 
guage.— N.  O.  Med.  Register. 


Any  reader  who  desires  a  treatise  on  physiology 
may  feel  himself  entirely  safe  in  ordering  this. — 
Western  Med.  and  Surg.  Journal. 

From  this  hasty  and  imperfect  allusion  it  will  he 
seen  by  our  readers  that  the  alterations  and  addi- 
tions to  this  edition  render  it  almost  a  new  work — 
and  we  can  assure  our  readers  that  it  is  one  of  the 

science  within  a  more" limited  compass.— Medical    best  sumrnariesof  the  existing  facts  of  physiological 
Examiner  \  scien.ce  within  the  reach  of  the  English  student  and 

physic-inn. — N.  Y.  Journal  of  Medicine. 

The  profession  of  this  country,  and  perhaps  also 
of  Europe,  have  anxiously  and  for  some  time  awaited 
the  announcement  of  this  new  edition  of  Carpenter's 
Human  Physiology.  His  former  editions  have  for 
many  years  been  almost  the  only  text-book  on  Phy- 
siology in  all  our  medical  schools,  and  its  circula- 
The  changes  are  too  numerous  to  admit  of  an  ex-  tion  among  the  profession  has  been  unsurpassed  by 
tended  notice  in  this  place.  At  every  point  where  '  any  work  in  uny  department  of  medical  science, 
the  recent  diligent  labors  of  organic  chemists  and  j  It  is  quite  unnecessary  for  us  to  speak  of  this 
micrographers  have  furnished  interesting  and  valu-  i  work  as  its  merits  would  justify.  The  mere  an- 
able  facts,  they  have  been  appropriated,  and  no  pains  nouncement  of  its  appearance  will  afford  the  highest 
have  been  spared,  in  so  incorporating  and  arranging  pleasure  to  every  student  of  Physiology,  while  its 
them  that  the  work  may  constitute  one  harmonious  .  perusal  will  be  of  infinite  service  m  advancing 
system. — Southern  Med.  and  Surg.  Journal.  j  physiological  science. — Ohio  Med.  and  Surg.  Journ. 


BY  THE  SAME  AUTHOR.     (Now  Ready.) 

PRINCIPLES  OF  COMPARATIVE   PHYSIOLOGY.     New  American,  from 

the  Fourth  and  Revised  London  edition.     In  one  large  and  handsome  octavo  volume,  with  over 

three  hundred  beautiful  illustrations,     pp.  752. 

The  delay  which  has  existed  in  the  appearance  of  this  work  has  been  caused  by  the  very  thorough 
revision  and  remodelling  which  it  has  undergone  at  the  hands  of  the  author,  and  the  large  number 
of  new  illustrations  which  have  been  prepared  for  it.  It  will,  therefore,  be  found  almost  a  new 
work,  and  fully  up  to  the  day  in  every  department  of  the  subject,  rendering  it  a  reliable  text-book 
for  all  students  engaged  in  this  branch  of  science.  Every  eii'ort  has  been  made  to  render  its  typo- 
graphical finish  and  mechanical  execution  worthy  of  its  exalted  reputation,  and  creditable  to'  the 
mechanical  arts  of  this  country. 

This  book  should  not  only  be  read  but  thoroughly  i  no  man,  we  believe,  could  have  brought  to  so  suc- 
studied  by  every  member  of  the  profession.  None  cessful  an  issue  as  Dr.  Carpenter,  ft  required  for 
are  too  wise  or  old,  to  be  benefited  thereby.  But  its  production  a  physiologist  at  once  deeply  read  in 
especially  to  the  younger  class  would  we  cordially  the  labors  of  others,  capable  of  taking  a  general, 
commend  it  as  best  fitted  of  any  work  in  the  English  '  critical,  and  unprejudiced  view  of  those  labors,  and 
language  to  qualify  them  for  the  reception  and  com-  j  of  combining  the  varied,  heterogeneous  materials  at 
prehension  of  those  truths  which  are  daily  being  de-  :  his  disposal,  so  as  to  form  an  harmonious  whole, 
veloped  in  physiology. — Medical  Counsellor.  I  We  feel  that  this  abstract  can  give  the  reader  a  very 


Without  pretending  to  it,  it  is  an  Encyclopedia  of 
the  subject,  accurate  and  complete  in  all  respects — 
a  truthful  reflection  of  the  advanced  state  at  which 
the  science  has  now  arrived. — Dublin  Quarterly 
Journal  of  Medical  Science. 

A  truly  magnificent  work — in  itself  a  perfect  phy- 
siological study. — Ranking's  Abstract. 

This  work  stands  without  its  fellow.  It  is  one 
few  men  in  Europe  could  have  undertaken;  it  is  one 


imperfect  idea  of  the  fulness  of  this  work,  and  no 
idea  of  its  unify,  of  the  admirable  manner  in  which 
material  has  been  brought,  from  the  most  various 
sources,  to  conduce  to  its  completeness,  of  the  lucid- 
ity of  the  reasoning  it  contains,  or  of  the  clearness 
of  language  in  which  the  whole  is  clothed.  Not  the 
profession  only,  but  the  scientific  world  at  large, 
must  feel  deeply  indebted  to  Dr.  Carpenter  for  this 
great  work.  It  must,  indeed,  add  largely  even  to 
his  high  reputation. — Medical  Times. 


BY  THE  SAME  AUTHOR.     (Preparing.) 

PRINCIPLES  OF   GENERAL   PHYSIOLOGY,    INCLUDING   ORGANIC 

CHEMISTRY  AND  HISTOLOGY.     With  a  General  Sketch  of  the  Vegetable  and  Animal 
Kingdom.     In  one  large  and  very  handsome  octavo  volume,  with  several  hundred  illustrations. 
Tin-  subject  of  general  physiology  having  been  omitted  in  the  last  edition  of  the  author's  "  Com- 
parative Physiology,"  he  has  undertaken  to  prepare  a  volume  which  shall  present  it  more  tho- 
roughly and  fully  than  has  yet  been  attempted,  and  which  may  be  regarded  as  an  introduction  to 
his  other  works. 


AND    SCIENTIFIC    PUBLICATIONS. 


CARPENTER  (WILLIAM  B.),   M.  D.,  F.  R.  S., 

Examiner  in  Physiology  and  Comparative  Anatomy  in  the  University  of  London. 

ELEMENTS  (OR  MANUAL)  OF  PHYSIOLOGY,  INCLUDING  PHYSIO- 
LOGICAL ANATOMY.  Second  American,  from  a  new  and  revised  London  edition.  With 
one  hundred  and  ninety  illustrations.  In  one  very  handsome  octavo  volume,  pp.  566. 

In  publishing  the  first  edition  of  this  work,  its  title  was  altered  from  that  of  the  London  volume, 
by  the  substitution  of  the  word  "  Elements1'  for  that  of  "  Manual,"  and  with  the  author's  sanction 
the  title  of  "  Elements"  is  still  retained  as  being  more  expressive  of  the  scope  of  the  treatise. 


To  say  that  it  is  the  best  manual  of  Physiology 
now  before  the  public,  would  not  do  sufficient  justice 
to  the  author. — Buffalo  Medical  Journal. 

In  his  former  works  it  would  seem  that  he  had 
exhausted  the  subject  of  Physiology.  In  the  present, 
aegivis  the  essence,  as  it  were,  of  the  whole. — JV.  Y. 
Journal  of  Me.dir.ine. 

Those  who  have  occasion  for  an  elementary  trea- 
tise on  Physiology,  cannot  do  better  than  to  possess 
themselves  of  the  manual  of  Dr.  Carpenter. — Medical 
Examiner. 


The  best  and  most  complete  exposd  of  modern 
Physiology,  in  one  volume,  extant  in  the  English 
language. — St.  Louis  Medical  Journal. 

With  such  an  aid  in  his  hand,  there  is  no  excuse 
for  the  ignorance  often  displayed  respecting  the  sub- 
jects of  which  it  treats.  From  its  unpretending  di- 
mensions, it  may  not  be  so  esteemed  by  those  anxious 
to  make  a  parade  of  their  erudition;  but  whoever 
masters  its  contents  will  have  reason  to  be  proud  »f 
his  physiological  acquirements.  The  illustrations 
are  well  selected  and  finely  executed. — Dublin  A'Ltd. 
Press. 


BY   THE   SAME   AUTHOR.      (I/I  Press.) 

THE  MICROSCOPE  AND  ITS  REVELATIONS.     In  one  handsome  volume, 

with  several  hundred  beautiful  illustrations. 

Various  literary  engagements  have  delayed  the  author's  progress  with  this  long  expected  work. 
It  is  now,  however,  in  an  advanced  slate  of  preparation,  and  may  be  expected  in  a  few  month*. 
The  importance  which  the  microscope  has  assumed  within  the  last  few  years,  bolh  as  a  guide  to 
the  practising  physician  who  wishes  to  avail  himself  of  the  progress  of  his  science,  and  as  an  indis- 
pensable assistant  to  the  physiological  and  pathological  observer,  has  caused  the  want  to  be  severely 
ifelt  of  a  volume  whioh  should  serve  as  a  guide  to  the  learner  and  a  book  of  reference  to  the  more 
Advanced  student.  This  want  Dr.  Carpenter  has  endeavored  to  supply  in  the  present  volume.  His 
great  practical  familiarity  with  the  instrument  and  all  its  uses,  and  his  acknowledged  ability  as  a 
teacher,  arc  a  sufficient  guarantee  that  the  work  will  prove  in  every  way  admirably  adapted  to  its 
purpose,  and  superior  to  any  as  yet  presented  to  the  scientific  world. 

BY   THE   SAME   AUTHOR. 

A  PRIZE  ESSAY  ON  THE  USE  OF  ALCOHOLIC  LIQUORS  IN  HEALTH 

AND  DISEASE.     New  edition,  with  a  Preface  by  D.  F.  CONDIE,  M.  D.,  and  explanations  of 
scientific  words.     In  one  neat  12mo.  volume,    pp.  178.     (Just  Issued.) 


CHELIUS   (J.  M.),   M.  D., 
Professor  of  Surgery  in  the  University  of  Heidelberg,  &c. 

A  SYSTEM  OF  SURGERY.     Translated  from  the  German,  and  accompanied 

with  additional  Notes  and  References,  by  JOHN  F.  SOUTH.     Complete  in  three  very  large  octavo 
volumes,  of  nearly  2200  pages,  strongly  bound,  with  raised  bands  and  double  titles. 


We  do  not  hesitate  to  pronounce  it.  the  best  and 
.  most  comprehensive  system  of  modern  surgery  with 
which  weareacquamted. — Medico-Ckirurgical  Re- 
view. 

The  fullest  and  ablest  digest  extant  of  all  that  re- 


lates to  the  present  advanced  state  of  surgical  pa- 
thology.— American  Medical  Journal. 

The  most  learned  and  complete  systematic  treatise 
now  extant.—  Edinburgh.  Medical  Journal. 


CLYMER  (MEREDITH),  M .  D.,  &c. 
FEVERS;     THEIR    DIAGNOSIS,    PATHOLOGY,    AND    TREATMENT. 

Prepared  and  Edited,  with  large  Additions,  from  the  Essays  on  Fever  in  Tweedie's  Library  <jl 
Practical  Medicine.     In  one  octavo  volume,  ol  600  pages. 


CHRISTISON  (ROBERT),  M.  D.,  V.  P.  R.  S.  E.,  &c. 
A  DISPENSATORY;  or,  Commentary  on  the  Pharmacopoeias  of  Great  Britain 

and  the  United  States;  comprising  the  Natural  History,  Description,  Chemistry,  Pharmacy.  Ac- 
tions, Uses,  and  Doses  of  the  Articles  of  the  Materia  Medica.  Second  edition,  revised  and  im- 
proved, with  a  Supplement  containing  the  most  important  New  Remedies.  With  copious  Addi- 
tions, and  two  hundred  and  thirteen  large  wood-engravings.  By  R.  EGLESFELD  GRIFFITH,  M.  D. 
In  one  very  large  and  handsome  octavo  volume,  of  over  1000  pages. 

It  is  not  needful  that  w^  should  compare  it  with        There  is  not  in  any  language  a  more  complete  and 
the  other  pharmacopoeias  extant,  which  enjoy  and    perfect  Treatise. — JV.  Y.  Annalist. 
merit  the  confidence  of  the  profession  :  it  is  enough  |      In   conciusjon)   we   nee()    Bcarcelv  say   that  we 


n  has  escaped  our  scrutiny.  We  cordially  recom- 


We  earnestly  recommend  Dr.  Christison's  Dis- 
rnend  this  work  to  such  of  our  readers  as  are  in  need  pensatory  to  all  our  readers,  as  an  indispensable 
of  a  Dispensatory.  They  cannot  make  choice  of  a  companion,  not  in  theStudy  only,  but  in  theSurgery 
(•etter. —  Wtsttrn  journ.  of  Medicine  and  Surgery.  also. — British  and  Foreign  Medical  Review. 


8 


BLANCHARD  &  LEA'S  MEDICAL 


CON  DIE  (D.  F.),  M.  D.,  &.C. 
A  PRACTICAL  TREATISE  ON  THE  DISEASES  OF  CHILDREN.    Fourth 

edition,  revised  and  augmented.  In  one  large  volume,  Svo.,  of  nearly  750  pages.  (Lately  Issued.) 
FROM  THE  AUTHOR'S  PREFACE. 

The  demand  for  another  edition  has  afforded  the  author  an  opportunity  of  again  subjecting  the 
entire  treatise  to  a  careful  revision,  and  of  incorporating  in  it  every  important  observation  recorded 
since  the  appearance  of  the  last  edition,  in  reference  to  the  pathology  and  therapeutics  of  the  several 
diseases  of  which  it  treats. 

In  the  preparation  of  the  present  edition,  as  in  those  which  have  preceded,  while  the  author  has 
appropriated  to  his  use  every  important  fact  that  he  has  found  recorded  in  the  works  of  others, 
having  a  direct  bearing  upon  either  of  the  subjects  of  which  he  treats,  and  the  numerous  valuable 
observations — pathological  as  well  as  practical — dispersed  throughout  the  pages  of  the  medical 
journals  of  Europe  and  America,  he  has,  nevertheless,  relied  chiefly  upon  his  own  observations  and 
experience,  acquired  during  a  long  and  somewhat  extensive  practice,  and  under  circumstances  pe- 
culiarly well  adapted  for  the  clinical  study  of  the  diseases  of  early  life. 

Every  species  of  hypothetical  reasoning  has,  as  much  as  possible,  been  avoided.  The  author  has 
endeavored  throughout  the  work  to  confine  himself  to  a  simple  statement  of  well-ascertained  patho- 
logical facts,  and  plain  therapeutical  directions — his  chief  desire  being  to  render  it  what  its  title 
imports  it  to  be,  A  PRACTICAL  TREATISE  ON  THE  DISEASES  OF  CHILDREN. 

Dr.  Condie's  scholarship,  acumen,  industry,  and  [      We  feel  assured  from  actual  experience  that  no 
practical  sense  are  manifested  in  this,  as  in  all  his  '  physician's  library  can  be  complete  without  a  copy 
numerous  contributions  to  science. — Dr.  Holmes' s    of  this  work. — N.  Y.  Journal  of  Medicine. 
Report  to  the  American  Medical  Association. 

__,,..          A  veritable  psediatnc  encyclopaedia,  and  an  honor 

Taken  as  a  whole,  in  our  judgment,  Dr.  Condie is  ;  to  Amcrican  medical  literature.— Okio  Medical  and 
Treatise  \s  the  one  from  the  perusal  of  which  the  ;  Surgical  Journal 
practitioner  iu  this  country  will  rise  with  the  great-  j 

est  satisfaction  — Western  Journal  of  Medicine  and  j  We  feel  persuaded  that  the  American  medical  pro- 
fession will  soon  regard  it  not  only  as  a  very  good, 
but  as  the  VERY  BEST  "  Practical  Treatise  on  the 
Diseases  of  Children." — American  MedicalJournal . 


Surgery. 

One  of  the  best  works  upon  the  Diseases  of  Chil- 
dren in  the  English  language. — Western  Lancet. 

Perhaps  the  most  full  and  complete  work  now  be- 
fore the  profession  of  the  United  States;  indeed,  we  !  work  on  the  diseases  of  children  in  the  English 
may  say  in  the  English  language.  It  is  vastly  supe-  language,  and,  notwithstanding  all  that  has  oeen 
rior  to  most  of  its  predecessors. — Transylvania  Med.  published,  we  still  regard  it  iu  that  light. — Medical 
Journal.  1  Examiner. 


We  pronounced   the  first  edition  to  he  the  best 


COOPER  (BRANSBY   B.),  F.  R.  S.3 

Senior  Surgeon  to  Guy's  Hospital,  &c. 

LECTURES  ON  THE  PRINCIPLES  AND    PRACTICE   OF   SURGERY. 

In  one  very  large  octavo  volume,  of  750  pages.    (Lately  Issued.) 

For  twenty-five  years  Mr.  Bransby  Cooper  has 
been  surgeon  to  Guy's  Hospital;  and  the  volume 
before  us  may  he  said  to  consist  of  an  account  of 
the  results  of  his  surgical  experience  during  that 
long  period.  We  cordially  recommend  Mr.  Bransby 


Lectures  as  a  most  valuable  addition  tc 


COOPER  (SIR  ASTLEY   P.),   F.  R.  S.,  &c. 
A  TREATISE  ON  DISLOCATIONS  AND  FRACTURES  OF  THE  JOINTS. 

Edited  by  BRANSBY  B.  COOPER,  F.  R.  S.,  &c.  With  additional  Observations  by  Prof.  J.  C. 
WARREN.  A  new  American  edition.  In  one  handsome  octavo  volume,  of  about  500  pages,  with 
numerous  illustrations  on  wood. 


BY   THE   SAME   AUTHOR. 


ON  THE  ANATOMY  AND  TREATMENT  OF  ABDOMINAL  HERNIA. 

One  large  volume,  imperial  Svo.,  with  over  130  lithographic  figures. 


BY   THE   SAME   AUTHOR. 

ON   THE   STRUCTURE  AND  DISEASES   OF  THE  TESTIS,  AND  ON 

THE  THYMUS  GLAND.     One  vol.  imperial  8vo.,  with  177  figures,  on  29  plates. 

BY   THE   SAME   AUTHOR. 

ON  THE  ANATOMY  AND  DISEASES   OF  THE  BREAST,  with  twenty- 

five  Miscellaneous  and  Surgical  Papers.     One  large  volume,  imperial  8vo.,  with  252  figures,  on 
36  plates. 

These  last  three  volumes  complete  the  surgical  writings  of  Sir  Astle^  Cooper.  They  are  very 
handsomely  printed,  with  a  large  number  of  lithographic  plates,  executed  in  the  best  style,  and  are 
presented  at  exceedingly  low  prices. 


CARSON   (JOSEPH),  M.  D., 

Professor  of  Materia  Medica  and  Pharmacy  in  the  University  of  Pennsylvania. 

SYNOPSIS  OF  THE  COURSE  OF  LECTURES  ON  MATERIA  MEDICA 

AND  PHARMACY,  delivered  in  the  University  of  Pennsylvania.    In  one  very  neat  octavo 
volume.  ol'208  pages. 


AND    SCIENTIFIC    PUBLICATIONS. 


CHURCHILL  (FLEET WOOD),  M.  D.,  M.  R.  I.  A. 
ON  THE  THEORY  AND  PRACTICE  OF  MIDWIFERY.  A  new  American, 

from  the  last  and  improved  English  edition.  Edited,  with  Notes  and  Additions,  by  D.  FRANCIS 
CONDIE,  M.  D.,  author  of  a  "Practical  Treatise  on  the  Diseases  of  Children,"  &c.  With  139 
illustrations.  In  one  very  handsome  octavo  volume,  pp.  510.  (Lately  Issued.) 


To  bestow  praise  on  a  book  that  has  received  such 
marked  approbation  would  be  superfluous.  We  need 
only  say,  therefore,  that  if  the  first  edition  was 
thought  worthy  of  a  favorable  reception  by  the 
medical  public.,  We  can  confidently  affirm  that  this 
will  be  found  much  more  so.  The  lecturer,  the 
practitioner,  and  the  student,  may  all  have  recourse 
to  its  pages,  and  derive  from  their  perusal  much  in- 
terest and  instruction  in  everything  relating  to  theo- 
retical and  practical  midwifery. — Dublin  Quarterly 
Journal  of  Medical  Science, 

A  work  of  very  great  merit,  and  such  as  we  can 
confidently  recommend  to  the  study  of  every  obste- 
tric practitioner. — London  Medical  Gazette. 

This  is  certainly  the  most  perfect  system  extant. 
It  is  the  best  adapted  for  the  purposes  of  a  text- 
book, and  that  which  he  whose  necessities  confine 
him  to  one  book,  should  select  in  preference  to  all 
others. — Southern  Medical  and,  Surgical  Journal. 

The  most  popular  work  on  midwifery  ever  issued 
from  the  American  press. — Charleston  Med.  Journal. 

Were  we  reduced  to  the  necessity  of  having  but 
one  work  on  midwifery,  and  permitted  to  choose, 
we  would  unhesitatingly  take  Churchill. — Western 
Med.  and  Surg.  Journal. 

It  is  impossible  to  conceive  a  more  useful  and 
elegant  manual  than  Dr.  Churchill's  Practice  of 
Midwifery. — Provincial  Medical  Journal. 

Certainly,  in  our  opinion,  the  very  best  work  on 
the  subject  which  exists. — If.  Y.  Annalist. 


•No  work  holds  a  higher  position,  or  is  more  de- 
serving of  being  placed  in  the  hands  of  the  tyro, 
the  advanced  student,  or  the  practitioner. — Medical 
Examiner. 

Previous  editions,  under  the  editorial  supervision 
of  Prof  R.  M.  Huston,  have  been  received  with 
marked  favor,  and  they  deserved  it;  but  this,  re- 
printed from  a  very  late  Dublin  edition,  carefully 
revised  and  brought  up  by  the  author  to  the  present 
time,  does  present  an  unusually  accurate  and  able 
exposition  of  every  important,  particular  embraced 
in  the  department  of  midwifery.  *  *  The  clearness, 
directness,  and  precision  of  its  teachings,  together 
with  the  great  amount  of  statistical  research  which 
its  text  exhibits,  have  served  to  place  it  already  in 
the  foremost  rank  of  works  in  tins  department  of  re- 
medial science. — N.  O.  Med.  and  Surg.  Journal. 

In  our  opinion,  it  forms  one  of  the  best  if  not  the 
very  best  text-book  and  epitome  of  obstetric  science 
which  we  at  present  possess  in  the  English  lan- 
guage.—  Monthly  Journal  of  Medical  Science. 

The  clearness  and  precision  of  style  in  which  it  is 
written,  and  the  great  amount  of  statistical  research 
which  it  contains,  have  served  to  place  it  in  the  first 
rank  of  works  in  this  department  of  medical  science. 
—  N.  Y.  Journal  of  Medicine. 

Few  treatises  will  be  found  better  adapted  as  a 
text-book  for  the  student,  or  as  a  manual  for  the 
frequent  consultation  of  the  young  practitioner. — 
American  Medical  Journal. 


BY   THE   SAME   AUTHOR. 


ON  THE  DISEASES  OF  INFANTS  AND  CHILDREN. 

handsome  volume  of  over  600  pages. 


In  one  large  and 


We  regard  this  volume  as  possessing  more  claims 
to  completeness  than  any  other  of  the  kind  with 
which  we  are  acquainted.  Most  cordially  and  earn- 
estly, therefore,  do  we  commend  it  to  our  profession- 
al brethren,  and  we  feel  assured  that  the  stamp  of 
their  approbation  will  indue  time  be  impressed  upon 
it.  After  an  attentive  perusal  of  its  contents,  we 
hesitate  not  to  say,  that  it  is  one  of  the  most  com- 
prehensive ever  written  upon  the  diseases  of  chil- 
dren, and  that,  for  copiousness  of  reference,  extent  of 
research,  and  perspicuity  of  detail,  it  is  scarcely  to 
be  equalled,  and  not  to  be  excelled,  in  any  lan- 
guage.— Dublin  Quarterly  Journal. 

After  this  meagre,  and  we  know,  very  imperfect 
notice  of  Dr.  Churchill's  work,  we  shall  conclude 
bj-  saying,  that  it  is  one  that  cannot  fail  from  its  co- 
piousness, extensive  research ,  and  general  accuracy, 
to  exalt  still  higher  the  reputation  of  the  author  in 
this  country.  The  American  reader  will  be  particu- 
larly pleased  to  find  that  Dr.  Churchill  has  done  full 
justice  throughout  his  work  to  the  various  A  mericun 
authors  on  this  subject.  The  names  of  Dewees, 
Eberle,  Condie,  and  Stewart,  occur  on  nearly  every 
page,  and  these  authors  are  constantly  referred  to  by 
the  author  in  terms  of  the  highest  praise,  and  with 
the  most  liberal  courtesy. — The  Medical  Examiner. 


The  present  volume  will  sustain  the  reputation 
acquired  by  the  author  from  his  previous  works. 
The  reader  will  find  in  it  full  and  judicious  direc- 
tions for  the  management  of  infants  at  birth,  and  a. 
compendious,  but  clear  account  of  the  diseases  to 
which  children  are  liable,  and  the  most  successful 
mode  of  treating  them.  \Ve  must  not  close  this  no- 
tice without  calling  attention  to  the  author's  style, 
which  is  perspicuous  and  polished  to  a  degree,  we 
regret  to  say,  not  generally  characteristic  of  medical 
works.  We  recommend  the  work  of  Dr.  Churchill 
most  cordially,  both  to  students  and  practitioners, 
as  a  valuable  and  reliable  guide  in  the  treatment  of 
the  diseases  of  children. — Am.  Journ.  of  the  Med. 
Sciences. 

We  know  of  no  work  on  this  department  of  Prac- 
tical Medicine  which  presents  so  candid  and  unpre- 
judiced a  statement  or  posting  up  of  our  actual 
knowledge  as  this. — 2V.  Y.  Journal  of  Medicine. 

Its  claims  to  merit  both  as  a  scientific  and  practi- 
cal work,  are  of  the  highest  order.  Whilst  we 
would  not  elevate  it  above  every  other  treatise  on 
the  same  subject,  we  certainly  be!  ieve  that  very  few 
are  equal  to  it,  and  none  superior. — Southern  Med. 
and  Surgical  Journal. 


BY   THE  SAME   AUTHOR. 


ESSAYS  ON  THE  PUERPERAL  FEVER,  AND  OTHER  DISEASES  PE- 
CULIAR TO  WOMEN.  Selected  from  the  writings  of  British  Authors  previous  to  the  close  of 
the  Eighteenth  Century.  In  one  neat  octavo  volume,  of  about  four  hundred  and  fifty  pages. 


To  these  papers  Dr.  Churchill  has  appended  notes, 
embodying  whatever  information  has  been  laid  be- 
fore the  profession  since  their  authors'  time.  He  hag 
also  prefixed  to  the  Essays  on  Puerperal  Fever, 
which  occupy  the  larger  portion  of  the  volume,  an 
interesting  historical  sketch  of  the  principal  epi- 


demics of  that  disease.  The  whole  forms  a  very 
valuable  collect  ion  of  papers,  by  professional  writers 
of  eminence,  onsomeof  the  most  important  accidents 
to  which  the  puerperal  female  is  liable. — American 
Journal  of  Medical  Sciences. 


10 


BLANCHARD    &    LEA'S    MEDICAL, 


CHURCHILL  (FLEETWOOD),    M.  D.,  M  .  R.  I .  A.,    &c. 

OX  THE  DISEASES  OF  WOMEN;  including  those  of  Pregnancy  and  Child- 

lied.  A  new  American  edition,  revised  by  the  Author.  With  Notes  and  Additions,  by  D  FRAN- 
CIS CONDIE,  M.  D.,  author  of  "A  Practical  Treatise  on  the.  Diseases  of  Children."  In  one  large 
and  handsome  octavo  volume,  with  wood-cuts,  pp.  684.  (Just  Issued.) 


We  now  regretfully  take  leave  of  Dr.  Churchill's 
book.  Had  our  typographical  limits  permitted,  we 
should  gladly  have  borrowed  more  from  its  richly 
stored  pages.  In  conclusion,  we  heartily  recom- 
mend it  to  the  profession,  and  would  at  the  same 
time  express  our  firm  conviction  that  it  will  not  only 
add  to  the  reputation  of  its  author,  but  will  prove  a 
work  of  great  and  extensive  utility  to  obstetric 
practitioners. — Dublin  Medical  Press. 

Former  editions  of  this  work  have  been  noticed  in 
previous  numbers  of  the  Journal.  The  sentiments  of 
high  commendation  expressed  in  those  notices,  have 
only  to  be  repeated  in  this;  not  from  the  fact  that 
the  profession  at  large  are  not  aware  of  the  high 
merits  which  this  work  really  possesses,  but  from  a 
desire  to  see  the  principles  and  doctrines  therein 
contained  more  generally  recognized,  and  more  uni- 
versally carried  out  in  practice. — ff.  Y.  Journal  of 
Medicine. 

We  know  of  no  author  who  deserves  that  appro- 
bation, on  "the  diseases  of  females,"  to  the  same 
extent  that  Dr.  Churchill  does.  His,  indeed,  is  the 
only  thorough  treatise  we  know  of  on  the  subject; 
and  it  may  be  commended  to  practitioners  and  stu- 
dents as  a  masterpiece  in  its  particular  department. 
The  former  editions  of  this  work  have  been  com- 
mended strongly  in  this  journal,  and  they  have  won 
their  way  loan  extended,  and  a  well-deserved  popu- 


larity. This  fifth  edition,  before  us.  is  well  calcu- 
lat.i-d  to  maintain  Dr.  Churchill's  high  reputation. 
It  was  revised  and  enlarged  by  the  author,  for  his 
American  publishers,  and  it  seems  to  us  that  there  is 
scarcely  any  species  of  desirable  information  on  its 
subjects  that  may  not  be  found  in  this  work. — The 
Western  Journal  of  Medicine  and  Surgery. 

We  are  gratified  to  announce  a  new  and  revised 
edition  of  Dr.  Churchill's  valuable  work  on  the  dis- 
eases of  females  We  have  ever  regarded  it  as  one 
of  the  very  best  works  on  the  subjects  embraced 
within  its  scope,  in  the  English  language;  and  the 
present  edition,  enlarged  and  revised  by  the  author, 
renders  it  still  more  entitled  to  the  confidence  of  the 
profession.  The  valuable  notes  of  Prof  Huston 
have  been  retained,  and  contribute,  in  no  small  de- 
gree, to  enhance  the  value  of  the  work.  It  is  a 
source  of  congratulation  that  the  publishers  have 
permitted  the  author  to  be,  in  this  instance,  his 
own  editor,  thus  securing  all  the  revision  which 
an  author  alone  is  capable  of  making. — The  Wester* 
Lancet. 

Asa  comprehensive  manual  for  students,  or  a 
work  of  reference  for  practitioners,  we  only  speak 
with  common  justice  when  we  say  that  it  surpasses 
any  other  that  has  ever  issued  on  the  same  sub- 
ject from  the  British  press. — The  Dublin  Quarterly 
Journal. 


DICKSON   (S.    H.),    M.  D., 

Professor  of  Institutes  and  Practice  of  Medicine  in  the  Medical  College  of  South  Carolina. 

ELEMENTS  OF  MEDICINE;   a  Compendious  View  of  Pathology  and  Thcra- 

peutics,  or  the  History  and  Treatment  of  Diseases.     In  one  large  and  handsome  octavo  volume 

of  nearly  800  pages     '(Now  Ready.) 

As  a  text- book  on  the  Practice  of  Medicine  for  the  student,  and  as  a  condensed  work  of  reference 
for  the  practitioner,  this  volume  will  have  strong  claims  on  the  attention  of  the  American  profession. 
Few  physicians  have  had  wider  opportunities,  than  the  author,  for  observation  and  experience,  and 
few  perhaps  have  used  them  belter.  As  the  result  of  a  life  of  study  and  practice,  therefore,  the 
present  volume  will  doubtless  be  received  with  the  welcome  it  deserves. 

From  the  Preface. 

The  present  volume  is  intended  as  an  aid  to  young  men  who  have  engaged  in  the  study  of  medi- 
cine, to  physicians  who  have  recently  assumed  the  responsibilities  of  practice,  and  to  my  fellow 
professors  of  the  Institutes  of  Medicine,  and  private  instructors  who  have  felt  the  difficulty  of  com- 
municating to  the  two  first  classes  the  knowledge  which  they  are  earnestly  seeking  to  acquire. 
Having  been  a  teacher  of  medicine  for  thirty  years,  and  a  student  more  than  forty,  I  must  have 
accumulated  some  experience  in  both  characters.  I  have  prepared  and  printed  for  {hose  in  attend- 
ance on  my  lectures  many  successive  manuals  or  text-books.  I  have  also  written  and  published 
several  volumes  on  medical  subjects  in  general.  The  following  pages  are  the  result  of  a  careful 
collation  of  all  that  has  been  esteemed  valuable  in  both,  with  such  matter  as  continued  study  and 
enlarged  experience  has  enabled  me  to  add. 


DEWEES   (W.    P.),   M.D.,    &.c. 
A   COMPREHENSIVE   SYSTEM  OF   MIDWIFERY.     Illustrated  by   occa- 

sional  Cases  and  many  Engravings.     Twelfth  edition,  with  the  Author's  last  Improvements  and 
Corrections.     In  one  octavo  volume,  of  600  pages.     (Just  Issued.) 

BY   THE   SAME   AUTHOR. 

A  TREATISE  ON  THE  PHYSICAL  AND  MEDICAL  TREATMENT  OF 

CHILDREN.     Tenth  edition.    In  one  volume,  octavo,  548  pages.     (Just  Issued.) 


BY   THE   SAME   AUTHOR. 


A  TREATISE  ON   THE   DISEASES   OF   FEMALES.     Tenth   edition. 

one  volume,  octavo,  532  pages,  with  plates.     (Just  Issued.) 


In 


DANA   (JAMES     D). 
ZOOPHYTES  AND  CORALS.     In  one  volume,  imperial  quarto,  extra  cloth, 

with  wood-cuts.    Also,  AN  ATLAS,  in  one  volume,  imperial  folio,  with  sixty-one  magnificent 
plates,  colored  after  nature.    Bound  in  half  morocco. 


DE    LA    BECHE   (SIR    HENRY    T.),   F.  R.  SM  &c. 
THE  GEOLOGICAL  OBSERVER.     In  one  very  large  and  handsome  octavo 

volume,  of  700  pages.     With  over  three  hundred  wood-cuts.     (Lately  Issued.) 


AND    SCIENTIFIC    PUBLICATIONS. 


11 


DRUITT   (ROBERT),   M.R.  C.S.,   &c. 
THE  PRINCIPLES  AND  PRACTICE  OF  MODERN  SURGERY.     A  new 

American,  from  the  improved  London  edition.  Edited  by  F.  W.  SARGENT,  M.  D.,  author  of 
"Minor  Surgery,"  &e.  Illustrated  with  one  hundred  and  ninety-three  wood-engravings.  In 
one  very  handsomely  printed  octavo  volume,  of  576  large  pages. 


Dr.  Drain's  researches  into  the  literature  of  his 
subject  have  been  not  only  extensive,  but  well  di- 
rected;  the  most  discordant  authors  are  fairly  and 
impartially  quoted,  and,  while  due  credit  is  given 
to  each,  their  respective  merits  are  weighed  with 
an  unprejudiced  hand.  The  grain  of  wheat  is  pre- 
served, and  the  chaiT  is  unmercifully  stripped  off. 
The  arrangement  is  simple  and  philosophical,  and 
the  style,  though  clear  and  interesting,  is  so  precise, 
that  the  book  contains  more  information  condensed 
into  a  few  words  than  any  other  surgical  work  with 
which  we  are  acquainted. — London  Medical  Times 
and  Gazette,  February  18,  1S54. 

No  work,  in  our  opinion,  equals  it  in  presenting 
so  much  valuable  surgical  matter  in  so  small  a 
compass. — St.  Louis  Med.  and  Surgical  Journal. 

Druitt's  Surgery  is  too  well  known  to  the  Ameri- 
can medical  profession  to  require  its  announcement 
anywhere.  Probably  no  work  of  the  kind  has  ever 
been  more  cordially  received  and  extensively  circu- 
lated than  this.  The  fact  that  it  comprehends  in  a 
comparatively  small  compass,  all  the  essential  ele- 
ments of  theoretical  and  practical  Sureery — that  it 
is  found  to  contain  reliable  and  authentic  informa- 
tion on  the  nature  and  treatment  of  nearly  all  surgi- 
cal affections — is  a  sufficient  reason  for  the  liberal 
patronage  it  has  obtained.  The  editor,  Dr.  F.  W. 
Sararent,  has  contributed  much  to  enhance  the  value 
of  the  work,  by  such  American  improvements  as  are 
calculated  more  perfectly  to  adapt  it  to  our  own 
views  and  practice  in  this  country.  It  abounds 
everywhere  with  spirited  and  life-like  illustrations, 
which  to  the  young  surgeon,  especially,  are  of  no 
minor  consideration.  Every  medical  man  frequently 
needs  just  such  a  work  as  this,  for  immediate  refe- 
rence in  moments  of  sudden  emergency,  when  he  has 
not  time  to  consult  more  elaborate  treatises. — The 
Ohio  Medical  and  Surgical  Journal. 

The  author  has  evidently  ransacked  every  stand- 
ard treatise  of  ancient  and  modern  times,  and  all  that 


;ery 
uch 


is  renlly  practically  useful  at  the  bedside  will  be 
found  in  a  form  at  once  clear,  distinct,  and  interest- 
ing.— Edinburgh  Monthly  Medical  Journal. 

Druitt's  work,  condensed,  systematic,  lucid,  and 
practical  as  it  is,  beyond  most  works  on  Surger 
accessible  to  the  American  student,  has  had  muc 
currency  in  this  country,  and  under  its  present  au- 
spices promises  to  rise  to  yet  higlier  favor. — The 
Western  Journal  of  Medicine  and  Surgery. 

The  most  accurate  and  ample  resume  of  the  pre- 
sent state  of  Surgery  that  we  are  acquainted  with. — 
Dublin  Medical  Journal. 

A  better  book  on  the  principles  and  practice  of 
Surgery  as  now  understood  in  England  and  America, 
has  not  been  given  to  the  profession. — Boston  Medi- 
cal and  Surgical  Journal. 

An  unsurpassable  compendium,  not  only  of  Sur- 
gical, but  of  Medical  Practice. — London  Medical 
Gazette. 

This  work  merits  our  warmest  commendations, 
and  we  strongly  recommend  it  to  young  surgeons  as 
an  admirable  digest  of  the  principles  and  practice  of 
modern  Surgery. — Medical  Gazette. 

It  may  be  said  with  truth  that  the  work  of  Mr. 
Druitt  affords  a  complete,  though  brief  and  con- 
densed view,  of  the  entire  field  of  modern  surgery. 
We  know  of  no  work  on  the  same  subject  having  the 
appearance  of  a  manual,  which  includes  so  many 
topics  of  interest  to  the  surgeon  ;  and  the  terse  man- 
ner in  which  each  has  been  treated  evinces  a  most 
enviable  quality  of  mind  on  the  part  of  the  author, 
who  seems  to  have  an  innate  power  of  searching 
out  and  grasping  the  leading  facts  and  features  of 
the  most  elaborate  productions  of  the  pen.  It  is  a 
useful  handbook  for  the  practitioner,  and  we  should 
deem  a  teacher  of  surgery  unpardonable  who  did  not 
recommend  it  to  his  pupils.  In  our  own  opinion,  it 
is  admirably  adapted  to  the  wants  of  the  student. — 
Provincial  Medical  and  Surgical  Journal. 


DUNGLISON,    FORBES,   TWEEDIE,    AND   CONOLLY. 
THE  CYCLOPAEDIA  OF  PRACTICAL  MEDICINE:  comprising  Treatises  on 

the  Nature  and  Treatment  of  Diseases,  Materia  Medica,  and  Therapeutics,  Diseases  of  Women 
and  Children,  Medical  Jurisprudence,  &c.  &c.  In  four  large  super  royal  octavo  volumes,  of 
3254  double-columned  pages,  strongly  and  handsomely  bound. 

*_!(;*  This  work  contains  no  less  than  four  hundred  and  eighteen  distinct  treatises,  contributed  by 
six-ty-eight  distinguished  physicians. 


The  most  complete  work  on  Practical  Medicine 
extant;  or,  at  least,  in  our  language. —  Buffalo 
Medical  ami  Surgical  Journal. 

For  reference,  it  is  above  all  price  to  every  prac- 
titioner.—  Western  Lancet. 

One  of  the  most  valuable  medical  publications  of 
the  day — as  a  work  of  reference  it  is  invaluable. — 
Western  Journal  of  Medicine  and  Surgery. 

It  has  been  to  ug,  both  as  learner  and   teacher,  a 

work  for  ready  and  frequent  reference,  one  in  which 
modern  English  medicine  is  exhibited  in  the  most 
advantageous  light. — Medical  Examiner. 

We  rejoice  that  this  work  is  to  be  placed  within 
the  reach  of  the  profession  in  this  country,  it  being 


unquestionably  one  of  very  great  value  to  the  prac- 
titioner. This  estimate  of  it  has  not  been  formed 
from  a  hasty  examination,  but  after  an  intimate  ac- 
quaintance derived  from  frequent  consultation  of  it 
during  the  past  nine  or  ten  years.  The  editors  are 
practitioners  of  established  reputation,  and  the  list 
of  contributors  embraces  many  of  the  most  eminent 
professors  and  teachers  of  London,  Edinburgh,  Dub- 
lin, and  Glasgow.  It  is,  indeed,  the  great  merit  of 
this  work  that  tlie  principal  articles  have  been  fur- 
nished by  practitioners  who  have  not  only  devoted 
especial  attention  to  the  diseases  about  which  they 
have  written,  but  have  also  enjoyed  opportunities 
for  an  extensive  practical  acquaintance  with  them, 
and  whose  reputation  carries  the  assurance  of  their 
competency  justly  to  appreciate  the  opinions  of 
others,  while  it  stumps  their  own  doctrines  with 
high  and  just  authority. — American  Medical  Journ. 


DUNGLISON    (ROBLEY),    M.D.. 

Professor  of  the  Institutes  of  Medicine  in  the  Jefferson  Medical  College,  Philadelphia. 

HUMAN  HEALTH;  or,  the  Influence  of  Atmosphere,  and  Locality,  Change  of 

Air  and  Climate,  Seasons,  Food,  Clothing,  Bathing,  Exercise,  Sleep,  &c.  &c.,  onHealthy  Man; 
constituting  Elements  of  Hygiene.  Second  edition,  with  many  modifications  and  additions.  In 
one  octavo  volume,  of  464  pages. 


BLANCHARD    &    LEA'S    MEDICAL 


DUNGLISON    (ROBLEY),    M.D., 

Professor  of  Institutes  of  Medicine  in  the  Jefferson  Medical  College,  Philadelphia. 

MEDICAL   LEXICON;    a  Dictionary  of  Medical  Science,  containing  a  concise 

Explanation  of  the  various  Subjects  and  Terms  of  Physiology,  Pathology,  Hygiene,  Therapeutics, 
Pharmacology)  Obstetrics,  Medical  Jurisprudence,  &c.  With  the  French  and  other  Synonymes  ; 
Notices  of  Climate  and  of  celebrated  Mineral  Waters;  Formulae  for  various  Officinal,  Empirical, 
and  Dietetic  Preparations,  etc.  TWELFTH  KDITION,  revised.  In  one  very  thick  octavo  volume,  ot 
over  nine  hundred  large  double-columned  pages,  strongly  bound  in  leather,  with  raised  bands. 
(fiest  Issued.) 

Every  successive  edition  of  this  work  bears  the  marks  of  the  industry  of  the  author,  and  of  his 
determination  to  keep  it  fully  on  a  level  with  the  most  advanced  state  of  medical  science.  Thus 
nearly  FIFTEEN  THOUSAND  WORDS  have  been  added  to  it  within  the  last  few  years.  As  a  complete 
Medical  Dictionary,  therefore,  embracing  over  FIFTY  THOUSAND  DEFINITIONS,  in  all  the 
branches  of  the  science,  it  is  presented  as  meriting  a  continuance  of  the  great  favor  and  popularity 
which  have  carried  it,  within  no  very  long  space  of  time,  to  a  twelfth  edition. 

Every  precaution  has  been  taken  in  the  preparation  of  the  present  volume,  to  render  its  mecha- 
nical execution  and  typographical  accuracy  worthy  of  its  extended  reputation  and  universal  use. 
The  very  extensive  additions  have  been  accommodated,  without  materially  increasing  the  bulk  ol 
the  volume  by  the  employment  of  a  small  but  exceedingly  clear  type,  cast  for  this  purpose.  The 
press  has  been  watched  with  great  care,  and  every  effort  used  to  insure  the  verbal  accuracy  so  ne- 
cessary to  a  work  of  this  nature.  The  whole  is  printed  on  fine  white  paper  ;  and,  while  thus  exhi- 
biting in  every  respect  so  great  an  improvement  over  former  issues,  it  is  presented  at  the  original 
exceedingly  low  price. 


We  welcome  it  cordially ;  it  is  an  mlmirahle  work, 
and  indispensable  to  all  literary  medical  men.  The 
labor  which  has  been  bestowed  upon  it  is  something 
prodigious.  The  work,  however,  has  now  been 
done,  and  we  are  hnppy  in  the  thought  that  no  hu- 
man being  will  have  again  to  undertake  the  same 
gigantic  tas-k.  Revised  and  corrected  from  time  to 
time,  Dr.  Dunglison's  "  Medical  Lexicon"  will  last 
for  centuries. — British  and  Foreign  Med.  Chirurg. 
Review. 

The  fact  that  this  excellent  and  learned  work  has 
passed  through  eight  editions,  and  that  a  ninth  is 
rendered  necessary  by  the  demands  of  the  public, 
affords  .1  sufficient  evidence  of  the  general  apprecia- 
tion of  Dr.  Dunglison's  labors  by  the  medical  pro- 


fession in  England  and  America.     It  is  a  book  which  i  of  refere'n£ 


readers  to  its  peculiar  merits;  and  we  need  do 
little  more  than  state,  in  reference  to  the  present 
reissue,  that,  notwithstanding  the  large  additions 
previously  made  to  it,  no  fewer  than  four  thou- 
sand terms,  not  to  be  found  in  the  preceding  edi- 
tion, are  contained  in  the  volume  bi-fore  us. — 
Whilst  it  is  n  wonderful  monument  of  its  author's 
erudition  and  industry,  it  is  also  a  work  of  great 
practical  utility,  as  we  can  testify  from  our  own 
experience;  for  we  keep  it  constantly  within  our 
reach,  and  make  very  frequent  reference  to  it, 
nearly  always  finding  in  it  the  information  we  seek. 
— British  and  Foreign  Med.-Ckirurg.  Review. 

It  has  the  rare  merit  that  it  certainly  has  no  rival 
in   the  English   language  for  accuracy   and  extent 


The   terms  generally   include  short 


Times  and  Gazette.  information .     The  author's  labors  have  been  pro- 

In  taking  leave  of  our  author,  we  feel  compelled  i  perly  appreciated  by  his  own  countrymen  ;  and  we 
to  confess  that  his  work  bears  evidence  of  almost 
incredible  labor  having  been  bestowed  upon  its  com- 
position.—  Edinburgh  Journal  of  Med.  Sciences. 
A  miracle  of  labor  and  industry  in  one  who  has 
written  able  and  voluminous  works  on  nearly  every 
branch  of  medical  science.  There  could  be  no  more 


can  only  confirm  their  judgment,  by  recommending 
this  most  useful  volume  to  the  notice  of  our  cisat- 
lantic readers.  No  medical  library  will  be  complete 
without  it. — London  Med.  Gazette. 

It  is  certainly  more  complete  and  comprehensive 
than   any   with  which  we   are  acquainted   in   the 


useful  book  to  the  student  or   practitioner,  in  the    English    language.     Few,   in  fact,  could   be  found 

present  advancing  age,  than  one  in  winch  would  be    bet|er  qu!lljf£d  fh;in  Dr.  i)unglison  for  the  produc- 

found,  in  addition  to  the  ordinary  meaning  and  den- .,  tion   o?  Bnch   a   work.     Learned,  industrious,  per- 

vation  ot  medical  terms — so  many  of  which  are  of 

modern  introduction — concise  descriptions  of  their 

explanation  and  employment ;  and  all  this  and  much 

more  is  contained  in  the  volume  before  us.     It  is 

therefore  almost  as  indispensable  to  the  other  learned 

professions  as  to  our  own.     In  fact,  to  all  who  may 

haveoccasion  to  ascertain  the  meaning  of  any  word 

belonging  to  the  many  branches  of  medicine.    From 


severing,  and  accurate,  he  brings  to  the  task  all 
the  peculiar  talents  necessary  for  its  successful 
performance;  while,  at  the  same  time,  his  fami- 
liarity with  the  writings  of  the  ancient  and  modern 
"  masters  of  our  art,"  renders  him  skilful  to  note 
the  exact  usage  of  the  several  terms  of  science, 
and  the  various  modifications  which  medical  term 
itiology  has  undergone  with  the  change  of  theo- 


u  careful  examination  of  the  present  edition   we  can  ,  rieg  £/  the  progre|s  of  improvement.  —  American 
vouch  for  its  accuracy    and  for  it.  being  brought  <  Journal  of  t\K  §Ieliical  Sciences. 


voucn  tor  its  accuracy,  and  tor  its  being  broug 
quite  up  to  thedate  of  publication  ;  the  author  stat 
in  his  preface  that  he  hasadded  to  it  about  four  thou- 
sand terms,  which  are  not  to  be  found  in  the  prece- 
ding one.  —  Dublin  Quarterly  Journal  of  Medical 
Sciences. 

On   the  appearance  of  the  last   edition   of   this 
valuable  work,   we   directed  the  attention  of  our 


J/M 

One  of  the  most  complete  and  copious  known  to 
the  cultivators  of  medical  science. — Boston  Med. 
Journal. 

The  most  comprehensive  and  best  English  Dic- 
tionary of  medical  terms  extant. — Buffalo  Medical 
Journal. 


BY   THE   SAME   AUTHOR. 


THE  PRACTICE  OF  MEDICINE.     A  Treatise  on  Special  Pathology  and  The- 

rapeutics.     Third  Edition.     In  two  large  octavo  volumes,  of  fifteen  hundred  pages. 


Upon  every  topic  embraced  in  the  work  the  latest 
information  will  be  found  carefully  posted  up. — 
Medical  Examiner. 

The  student  of  medicine  will  find,  in  these  two 
elegant  volumes,  a  mine  of  facts,  a  gathering  of 


precepts  and  advice  from  the  world  of  experience, 
that   will  neive  him  with   courage,  and  faithfu ." 
direct  him  in  his  efforts  to  relieve  the  physical  si 


ferings  of  the  race. — Boston  Medical  and  Surgical 
Journal . 

It  is  certainly  the  most  complete  treatise  of  which 
we  have  any  knowledge. —  Western  Journal  of  Medi- 
cine and  Surgery. 

One  of  the  most  elaborate  treatises  of  the  kind 
we  have. — Southern  Med.  and  Surg.  Journal. 


AND    SCIENTIFIC    PUBLICATION'S. 


13 


DUNGLISON    (ROBLEY),    M.D., 

Professor  of  Institutes  of  Medicine  in  the  Jefiersou  Medical  College,  Philadelphia. 

HUMAN    PHYSIOLOGY.     Seventh   edition.     Thoroughly  revised    and  exten- 

sively  modified  and  enlarged,  with  nearly  five  hundred  illustrations.     In  two  large  and  hand- 
somely printed  octavo  volumes,  containing  nearly  1450  pages. 
It  hue  long  since  taken  rank  as  one  of  the  medi-  !  Physiology  in  the  English   langunge,  tmd  is  highly 

cal  classics  of  our  language.     To  say  that   it  is  l>y  '  creditable  to  the  author  and  publishers. — Canadian. 

far  the  best  text-book  of  physiology  ever  published     Medical  Journal. 

in  this  country,   is  but  echoing   the  general  testi-  • 

mony  of  the  profession. — N.  Y.  Journal  of  Medicine. 


There  is  no  single  book  we  would  recommend  to 
the  student  or  physician,  with  greater  confidence 
than  the  present,  because  in  it  will  be  found  a  mir- 
ror of  almost  every  standard  physiological  work  of 
the  day.  We  most  cordially  recommend  the  work 
to  every  member  of  the  profession,  and  no  student 


The  most  complete  and  sntisfnctory  system  of 
Physiology  in  the  English  language. — Ariier.  Med. 
Journal. 

The  best  work  of  the  kind  in  the  English  lan- 
guage.— Silliman's  Journal. 

The  most  fjull  and  complete  system  of  Physiology 


should  be  without  it.    It  is  the  completes!  work  on  |  in  our  language. — Western  Lancet. 
BY  THE   SAME   AUTHOR.      (Just  Issued.) 

GENERAL    THERAPEUTICS    AND    MATERIA  MEDIC  A;   adapted  for  a 

Medical  Text-book.     Fifth  edition,  much  improved.     With  one  hundred  and  eighty-seven  illus- 
trations,   lu  two  large  and  handsomely  printed  octavo  vols.,  of  about  1100  pages. 
The  new  editions  of  the  United  States  Pharmacopeia  and  those  of  London  and  Dublin,  have  ren- 
dered necessary  a  thorough  revision  of  this  work.     In  accomplishing  this  the  author  Iras  spared  no 
pains  in  rendering  it  a  complete  exponent  of  all  that  is  new  and  reliable,  both  in  the  departments 
of  Therapeutics  and  Maieria  Medica.     The  book  has  thus  been  somewhat  enlarged,  and  a  like  im- 
provement will  t>e  found  in  every  department  of  its  mechanical  execution.     As  a  convenient  text- 
book for  the  student,  therefore,  containing  within  a  moderate  compass  a  satisfactory  resume  of  its 
important  subject,  it  is  again  presented  as  even  more  worthy  than  heretofore  of  the  very  great  favor 
which  it  has  received. 

In  this  work  of  Dr.  Dunglison,we  recognize  the        As  a  text-book  for  students,  for  whom  it  is  par- 
same  untiring  industry  in  the  collection   and  em-     ticularly  designed,   we   know  of  none   superior  to 
bodying  of  facts  on  the  several  subjects  of  which  he    it. — St.  Louis  Medical  and  Surgical  Journal. 
treats,  that   has  heretofore  distinguished  him,  and        T  ,... 

we  cheerfully  point  to  these  volumes,  as  two  of  the        Ifc  Purports  to  be  a  new  edition,  but  it  is  rather 
most  interesting  that  we  know  of.     In  noticing  the    ?  new  book>  8O  greatly  has  it  been  improved,  both 
additions  to  tins,  the  fourth  edition,  there  is  very     m   lfh?  amount  and  quality  of  the  matter  which  it 
little  in  the  periodical  or  annual   literature  of  the    contains.— A'.  O.  Medical  and  Surgical  Journal. 
profession,   published    in   the    interval   which    has 

elapsed  since  the  issue  of  the  first,  that  has  escaped  We  bespeak  for  this  edition,  from  the  profession, 
the  careful  search  of  the  author.  As  a  book  for  an  increase  of  patronage  over  any  of  its  lormer 
reference,  it  is  invaluable.—  Charleston  Med.  Jour-  ones>  on  5ccrou.nt.  of  lts  increased  merit.  — A.  1. 
Ml  and  Review.  ;  Journal  of  Medicine. 

It  may  be  said  to  be  the  work  now  upon  the  sub-        We  consider  this  work  unequalled. — Boston  Mid . 
Jects  upon  which  it  treats.—  Western  Lancet.  '•  and  Surg.  Journal. 

BY   THE   SAME   AUTHOR. 

NEW  REMEDIES,  WITH  FORMULAE  FOR  THEIR  ADMINISTRATION. 

Sixth  edition,  with  extensive  Additions.     In  one  very  large  octavo  volume,  of  over  750  pages- 
One  of  the  most  useful  of  the  author's  works. —    diseases  and  for  remedies,  will  be  found  greatly  to 
Southern  Medical  and  Surgical  Journal.  enhance  its  value. — New  York  Med.  Gazette. 

The  great  learning  of  the  author,  and  his  remark- 
able industry  in  pushing  his  researches  into  every 
source  whence  information  is  derivable,  has  enabled 
him  to  throw  together  an  extensive  mass  of  facts 
and  statements,  accompanied  by  full  reference  to 
authorities;  which  last  feature  renders  the  work 
practically  valuable  to  investigators  who  desire  to 
examine  the  original  papers. — The  American  Journal 
of  Pharmacy. 


This  well-known  and  standard  book  has  now 
reached  its  sixth  edition,  and  has  been  enlarged  and 
improved  by  the  introduction  of  all  the  recent,  gifts 
to  therapeutics  which  the  last  few  years  have  so 
richly  produced,  including  the  anesthetic  agents, 
&c.  This  elaborate  and  useful  volume  should  be 
found  in  every  medical  library,  for  as  a  book  of  re- 
ference, for  physicians,  it  is  unsurpassed  by  any 
other  work  in  existence,  and  the  double  index  for 


DE  JONGH  (L.  J.),  M.  D.,  &c. 
THE  THREE  KINDS   OF  COD-LIVER  OIL,  comparatively  considered,  with 

their  Chemical  and  Therapeutic  Properties.  Translated,  with  an  Appendix  and  Cases,  by 
EDWARD  CAREY,  M  D.  To  which  is  added  an  article  on  the  subject  from  "Dunglison  on  New 
Remedies."  In  one  small  12mo.  volume,  extra,  cloth. 


DAY  (GEORGE  E.),  M .  D. 
A  PRACTICAL  TREATISE  ON  THE  DOMESTIC  MANAGEMENT  AND 

MORE  IMPORTANT  DISEASES  OF  ADVANCED  LIFE.  With  an  Appendix  on  a  new 
and  successful  mode  of  treating  Lumbago  and  other  forms  of  Chronic  Rheumatism.  One  volume, 
•octavo,  226  pages. 


FRICK  (CHARLES),  M.  D. 
RENAL    AFFECTIONS;    their  Diagnosis  and  Pathology. 

Oue  volume,  royal  12ruo.,  extra  cloth. 


With  illustrations 


14 


BLANCHARD    &   LEA'S    MEDICAL 


ERICHSEN    (JOHN), 
Professor  of  Surgery  in  University  College,  London,  &c. 

THE  SCIENCE  AND  ART  OF  SURGERY;  BEING  A  TREATISE  ON  SURGICAL 

INJURIES,  DISEASES,  AND  OPKRATIONS.  Edited  by  JOHN  H.  BRINTON,  M.  D.  initiated  with 
three  hundred  and  eleven  engravings  on  wood.  In  one  large  and  handsome  octavo  volume,  of 
over  nine  hundred  closely  printed  pages.  (Just  Issued.) 


It  is,  in  our  humble  judgment,  decidedly  the  best 
hook  of  the  kind  in  the  K.nglish  language.  Strange 
;";it  just  such  hooks  are  not oftener  produced  by  pub 
lie  teachers  of  surgery  in  this  country  and  Great 
Britain  Indeed,  it  is  a  matterof  great  astonishment, 
but  no  less  true  than  astonishing,  that  of  ihe  rnany 
works  on  surgery  repul.-lished  iu  this  country  within 
the  last  fifteen  or  twenty  years  as  text-books  for 
medical  snuients,  this  is  the  oiily  one,  that  even  ap- 
proximates to  the  fulfilment  of  the  peculiar  wains  of 
voungmen  just  entering  upon  t>>e  study  of  this  branch 
of  the  profession. —  Western  Jour,  of  Mest.  and  Surgery. 

Embracing,  as  will  be  perceived,  the  whole  surgi- 
cal domain,  and  enrh  division  of  itself  almost  com- 
plete and  perfect,  each  chapter  full  and  explicit,  each 
subject  faithfully  exhibited,  we  can  only  express  our 
extimate  of  it  in  the  ag^resate.  We  consider  it  an 
excellent  contribution  to  surgery,  as  probably  the 
best  single  volume  now  extant  on  the  subject,  and 
with  great  pleasure  we  add  it  to  our  text-books  — 
Nashville  Journal  of  Medicine  and  Sit.rgf.ry 

Its  value  is  greatly  enhanced  by  a  very  copious 
well-nrniiwed  index.  We  regard  this  as  one  of  the 
most  valuable  contributions  to  modern  surgery.  To 
one  entering  his  novitiate  of  practice,  we  regard  it 


the  most  serviceable  guide  which  he  can  consult.  He 
will  find  a  fulness  of  detail  leading  him  through  every 
step  of  the  operation,  and  not  deserting  him  until  the 
final  issue  of  the  case  is  decided.  For  the  same  rea- 
son WP  recommend  it  to  those  whose  routine  of  prac- 
tice lies  in  such  parts  of  the  country  that  they  must 
rarely  encounter  cases  requiring  surgical  manage- 
ment.—  Stethoscope. 

Prof.  "Rrjclisen's  work,  for  its  size,  has  not  been 
surpassed ;  his  nine  hundred  and  eigiit  pages,  pro- 
fu-fly  illustrated,  are  rich  in  physiological,  patholo- 
gical, and  operative  suggestions,  doctrines,  details, 
and  processes;  and  will  prove  a  reliable  resource 
for  information,  both  to  physician  and  surgeon,  in  the 
hour  of  peril — N.  0.  Ale.d.  and  Surg.  Journal. 

We  are  acquainted  with  no  other  work  wherein 
so  much  good  sense,  sound  principle,  and  practical 
inferences,  stamp  every  page.  To  say  more  of  the 
volume  would  be  useless;  to  say  less  would  he  doing 
injustice  to  a  production  which  we  consider  above 
all  others  iit  the  present  day,  and  superior  and  more 
complete  than  the  many  excellent  treatises  of  the 
Knglifth  and  Scotch  surgeons,  and  this  is  no  small 
encomium. — American  Lancet. 


ELLIS  (BENJAMIN),  M.D. 
THE   MEDICAL   FORMULARY:   being  a  Collection  of  Prescriptions,  derived 

from  the  writings  and  practice  of  many  of  the  most  eminent  physicians  of  America  and  Europe. 
Together  wiih  the  usual  Dietetic  Preparations  and  Antidotes  for  Poisons.  To  which  is  added 
an  Appendix,  on  the  Endermic  use  of  Medicines,  and  on  the  use  of  Ether  and  Chloroform.  The 
whole  accompanied  with  a  few  brief  Pharmacetitic  and  Medical  Observations.  Tenth  edition, 
revised  and  much  extended  by  ROBERT  P.  THOMAS,  M.  D.,  Professor  of  Materia  Medica  in  the 
Philadelphia  College  of  Pharmacy.  In  one  neat  octavo  volume,  of  two  hundred  and  ninety-six 
pages.  (Lately  Issued.) 

It  will  prove  particularly  useful  to  students  and 
young  practitioners,  as  the  most  important  prescrip- 


After  an  examination  of  the  new  matter  and  the 
alterations,  we  believe  the  reputation  of  the  work 
built  np  by  the  author,  and  the  late  distinguished 
editor,  will  continue  to  flourish  under  the  auspices 
of  the  present  editor,  who  has  the  industry  and  accu- 
racy, and,  we  would  say,  conscientiousness  requi- 
site for  the  responsible  task. — American  Journal  of 
Pharmacy,  March,  1854. 


tions  employed  in  modern  practice,  which  lie  scat 
tered  through  our  medical  literature,  are  here  col- 
lected and  ^conveniently  arranged  for  reference. — 
Charleston  Med.  Journal  and  Review. 


FOWNES  (GEORGE),   PH.  D.,  &c. 
ELEMENTARY    CHEMISTRY;    Theoretical  and  Practical.    With  numerous 

illustrations.  A  new  American,  from  the  last  and  revised  London  edition.  Edited,  with  Addi- 
tions, by  ROBERT  BRIDGES,  M.  D.  In  one  large  royal  12mo.  volume,  of  over  550  pages,  with  181 
wood-cuts,  sheep,  or  extra  cloth.  (Now  Ready.) 


We  know  of  no  better  text-book,  especially  in  the 
difficult  department  of  organic  chemistry,  upon 
which  it  is  particularly  full  and  satisfactory.  We 
would  recommend  it  to  preceptors  as  a  capital 
••  office  book"  for  their  students  who  are  beginners 
in  Chemistry.  It  is  copiously  illustrated  with  ex- 
cellent wood-cuts,  and  altogether  admirably  "got 
up." — iV.  J.  Medical  Reporter,  March,  1854. 

A  standard  manual,  which  has  long  enjoyed  the 
reputation  of  embodying  much  knowledge  in  a  small 
space.  The  author  hasachieved  tlie  difficult  task  of 
condensation  with  masterly  tact.  His  book  is  con- 
cise without  being  dry,  and  brief  without,  being  too 
dogmatical  or  general. —  Virginia  Med.  and  Surgical 
Journal. 


The  work  of  Dr.  Fownes  has  long  been  before 
the  public,  and  its  merits  have  been  fully  appreci- 
ated as  the  best  text-book  on  chemistry  now  in 
existence.  We  do  not,  of  course,  place  it  in  a  rank 
superior  to  the  works  of  Brande,  Graham,  Turner, 
Gregory,  or  Gmelin,  but  we  say  that,  as  a  work 
for  students,  it  is  preferable  to  any  of  them. — Lon- 
don Journal  of  Medicine. 

A  work  well  adapted  to  the  wants  of  the  student. 
It  is  an  excellent  exposition  of  the  chief  doctrines 
and  facts  of  modern  chemistry.  Thesizeof  the  work, 
and  still  more  the  condensed  yet  perspicuous  style 
in  which  it  is  written,  absolve  it  from  the  charges 
very  properly  urged  against  most  manuals  termed 
popular. — Edinburgh  Monthly  Journal  of  MeJical 
Science. 


FLINT  (AUSTIN),  M .  D., 

Professor  of  the  Theory  and  Practice  of  Medicine  in  the  University  of  Louisville,  &c. 

THE  PRINCIPLES  AND  PRACTICE  OF  PHYSICAL  EXPLORATION, 

applied  to  the  Diagnosis  of  Diseases  affecting  the  Organs  of  Respiration.    In  one  handsome 
octavo  volume.     (In  Press.) 

The  reputation  already  acquired  by  the  author  with  respect  to  his  researches  on  this  and  kindred 
topics,  is  sufficient  guarantee  that  he  will  accomplish  his  object  in  presenting  the  student  with  a 
pood  practical  text-book,  which  will  facilitate  the  acquirement  of  a  knowledge  oflb.it>  dilRctilt  sub- 
ject. The  work  will  be  ready  in  lime  for  the  Fall  sessions. 


AND   SCIENTIFIC    PUBLICATIONS. 


FERGUSSON   (WILLIAM),  F.  R.  S., 
Professor  of  Surgery  in  King's  College,  London,  &c. 

A  SYSTEM  OF  PRACTICAL  SURGERY.     Fourth  American,  from  the  third 

and  enlarged  London  edition.     In  one  large  and  beautifully  printed  octavo  volume,  of  al>out  seven 
hundred  pages,  with  three  hundred  and  ninety-three  handsome  illustrations.     (Just  Issued.) 
The  most  important  subjects  in  connection  with  j      No  work  was  ever  written  which  more   nearly 


practical  surgery  which  have  been  more  recently 
brought  under  the  notice  of,  and  discussed  by,  the 
surgeons  of  Great  Britain,  are  fully  aad  dispassion- 
ately considered  by  Mr.  Fergusson,  and  that  which 
was  before  \vanting  has  now  been  supplied^  so  that 
we  can  now  look  upon  it  as  a  work  on  practical  sur- 
eery  instead  of  one  on  operative  surgery  alone. 
There  was  some  ground  formerly  for  the  complaint 
before  alluded  to,  that  it  dwelt  too  exclusively  on 
operative  surgery  ;  but  this  defect  is  now  removed, 
and  the  book  is  more  than  ever  adapted  for  the  pur- 
poses of  the  practitioner,  whether  he  confines  him- 
self more  strictly  to  the  operative  department,  or 
follows  surgery  on  a  more  comprehensive  scale. — 
ttttdical  Times  and  Gazette. 


comprehended  the  necessities  of  the  student  and 
practitioner,  and  was  more  carefully  arranged  to 
that  single  purpose  than  this. — N.  Y.  Med.  and  Surg. 
Journal. 

The  addition  of  many  new  pages  makes  this  work 
more  tlianever  indispensable  to  the  student  and  prac- 
titioner.— Ranking'!  Abstract. 

Among  the  numerous  works  upon  surgery  pub- 
lished of  late  years,  we  know  of  none  we  value 
more  highly  than  the  one  before  us.  It  is  perhaps 
the  very  best,  we  have  for  a  text-book  and  for  ordi- 
nary reference,  being  concise  anil  eminently  practi- 
cal.— Southern  Med.  and  Surg.  Journal. 


GRAHAM   (THOMAS),   F.  R.  S., 
Professor  of  Chemistry  in  University  College,  London,  &e. 

THE  ELEMENTS  OF  CHEMISTRY.     Including  the  application  of  the  Science 

to  the  Arts.     With  numerous  illustrations.    With  Notes  and  Additions,  by  ROBERT  BRIDGES, 
M.  D.,  &c.  &c.     Second  American,  from  the  second  and  enlarged  London  edition 
PART  I.  (Lately  Isxiifsl)  large  8vo.,  430  pages,  1S5  illustrations. 
PART  II.  (Preparing)  to  match. 

The  great  changes  which  the  science  of  chemistry  has  undergone  within  the  last  few  years,  ren- 
der a  new  edition  of  a  treatise  like  the  present,  almost  a  new  work.  The  author  has  devoted 
several  years  to  the  revision  of  his  treatise,  and  has  endeavored  to  embody  in  it  every  fact  and 
inference  of  importance  which  has  been  observed  and  recorded  by  the  great  body  of  chemica! 
investigators  who  are  so  rapidly  changing  the  face  of  the  science.  In  this  manner  the  work  has 
been  greatly  increased  in  <ize,  and  the  number  of  illustrations  doubled  ;  while  the  labors  of  the  editor 
have  been  directed  towards  the  introduction  of  such  matters  as  have  escaped  the  attention  of  the 
author,  or  as  have  arisen  since  the  publication  of  the  first  portion  of  this  edition  in  London,  in  18">G. 
Printed  in  handsome  style,  and  at  a  very  low  price,  it  is  therefore  confidently  presented  to  the  pro- 
fession and  the  student  as  a  very  complete  and  thorough  text-book  of  this  important  subject. 

GRIFFITH  (ROBERT   E.),   M.  D.f  &c. 

A  UNIVERSAL  FORMULARY,  containing  the  methods  of  Preparing  and  Ad- 
ministering Officinal  and  other  Medicines.  The  whole  adapted  to  Physicians  and  Pharmaceu- 
tists. SECOND  EDITION,  thoroughly  revised,  with  numerous  additions,  by  ROBERT  P.  THOMAS. 
M.  D.,  Professor  of  Materia  Medica  in  the  Philadelphia  College  of  Pharmacy.  In  one  large  and 
handsome  octavo  volume,  of  over  six  hundred  pages,  double  columns.  (Just  Issued.) 
It  was  a  work  requiring  much  perseverance,  and  |  It  is  one  of  the  most  nsef'il  books  a  country  practi- 


published  was  looked  upon  as  by  far  the  besi 
work  of  its  kind  thai  had  issued  from  the  American 
pres«.  being  free  of  much  of  the  Trasiiy.  and  embrac- 


ingmost  ofthf -. .oil-officinal  fornwte  used  or  known  i  a#ng  phvsiciail.   is   rcally  {mmeiMe.-^M/oi.  Med. 


tioner  can  possibly  have  in  his  possession. — Medical 
Chronicle 
The  amount  of  useful,  every-day  matter,  for  a  prac- 


in  American.  English,  or  French  practice,  arranged 
under  tlie  head?  of  the  several  consiituenldrugs.  plac 
ing  the  receipt  under  its  more  important  constituent. 
Prof  Thoma*  has  certainl>  ••  improved."  as  well  as 
added  o  iliis  Formulary,  and  has  rendered  it  addition- 
ally deserving  of  ilie  confidence  of  pharmae.eulislj 
and  physicians.  —  Amtrican  Journal  of  Pharmacy  . 

We  are  happy  to  announce  a  new  and  improved 
edition  of  ttus.  one  of  the  most  valuable  and  useful 
works  lhat  have  emanated  from  an  American  pen. 
It  would  do  credit  to  any  country,  and  will  he  found 
of  daily  u>e'~uiriess  to  practitioners  of  medicine;  it  is 
better  adapted  10  their  purpose?  ihnn  the  disptsnsato 
ries  —  Southern  Alni.  and  Surg  Journal 

A  new  edition  of  iliU  well-known  work,  edited  by 
R.  P.  Thomas.  M  D..  afford*  occasion  for  renewing 


and  Surg.  Journal. 

Thi»  is  a  work  of  six  hundred  and  fifty  on-  pasres, 
embracing  all  on  the  subject  of  preparing  and  admi- 
nistering medicines  thai  can  he  desired  by  the  physi- 
cian and  pharmaceutist. —  Wtstern  Lancet. 

In  f  l\ort.  it  is  a  full  and  complete  work  of  the  kind, 
and  should  be  in  the  hands  of  every  physician  and 
apothecary. —  O  Med.  and  Surg.  Juurnal 

We  predict  n  great  sale  for  this  work,  and  we  espe- 
cially recommend  it  to  all  medical  teachers. — Rich- 
mond Stethoscope. 

This  edition  of  Dr.  Griffith's  work  has  been  greatly 
improved  by  the  revision  and  ample  additions  of  Dr. 
Thomas,  and  is  now,  we  believe,  one  of  tne  most 


K.  F.  inomas.  M    u..  atlora.-  occasion  lor  renewing  j  Thomas,  and  is   now.  we   believe,  one  ot  tne  roos 
our  commendation  of  so  useful  a  handbook,  which  !  complete  works  of  Us  kind  in  any  language     Th 
ought  to  be  universally  studied  by   medical  men  of    additions  amount  to   about  seventy   pages,  arid    no 
every  class,  ami  made  use  of  by  way  of  reference  by 
office   pup>ls.  a*  a  standard   authority.     It  has  been 
much  enlarged,  and   now  condenses  a  vast  amount 


of  needful  and  neeessnry  knowledge  in  small  corn- 


effort  has  been  spared  to  include  in  them  all  the  re- 
cent improvements  which  have  bne.il  published  in 
medical  journals,  and  systematic  treatises.  A  work 
of  this  kind  appears  10  us  indispensable  to  the  physi- 


re  cordially  recoru- 


pa*s     Tlie  more  ot'such  books  iff  better  for  the  pro-  I  ciau.  and  lliTc  is  none  we  can  rnor 
Ic-ssion  and  tlie  public  -  X.  V.  Med.  (Jazttte.  in.;nd.—  If.  Y.  Journal  of  Medicine. 

BY   THE   SAME   AUTHOR. 

MEDICAL  BOTANY;  or,  a  Description  of  all  the  more  important  Plants  used 

in  Medicine,  and  of  their  Properties,  Uses,  and  Modes  of  Administration.     In  one  large  octavo 
volume,  of  704  pages,  handsomely  printed,  with  nearly  350  illustrations  on  wood. 

GREGORY  (WILLIAM),   F.  R.  S.  E., 
LETTERS    TO  A  CANDID    INQUIRER    ON    ANIMAL    MAGNETISM. 

la  one  neat  volume,  royal  12ino.,  extra  cloth,    pp.  384. 


BLANCHARD  &  LEA'S  MEDICAL 


GROSS  (SAMUEL  D.),   M.  D., 

Professor  of  Surgery  in  the  University  of  Louisville,  &c. 

A   PRACTICAL    TREATISE    ON    THE    DISEASES,    INJURIES,   AND 

.MALFORMATION'S  OF  THE  UKINAKY  BLADDER,  THE  PROSTATE  GLAND,  AND 

THE  URETHRA.     Second  Edition,  revised  and  much  enlarged,  wiili  one  hundred  and  eighty- 

tour  illustrations.     In  one  large  and  very  htmdsoine  octavo  volume,  of  over  nine  hundred  pages. 

(Now  Ready.) 

The  author  has  availed  himself  of  the  opportunity  afforded  by  a  call  for  a  new  edition  of  this 
work,  to  thoroughly  revise  and  render  it  in  every  respect  worthy,  so  far  as  in  his  power,  of  the  very 
flattering  reception  which  has  been  accorded  to  it  by  'lie  profession.  The  new  matter  thus  added 
amounts  to  almost  one-third  of  the  original  work,  while  the  number  of  illustrations  has  been  nearly 
doubled.  These  additions  pervade  every  portion  of  the  work,  which  thus  has  rather  the  aspect  of 
a  new  treatise  than  a  new  edition.  In  its  present  improved  form,  therefore,  it  may  confidently  be 
|i:<  <cntcd  as  a  complete  and  reliable  storehouse  of  information  on  this  important  class  of  diseases, 
and  as  in  every  way  fitted  to  maintain  the  position  which  it  has  acquired  in  Europe  and  in  this 
<;ounlry,  as  the  standard  of  authority  on  the  subjects  treated  of. 

On  the  appearance  of  the  first  edition  of  this  work,  |  away  this  reproach  ;  and  so  completely  hag  the  task 
the  lending  English  medical  review  predicted  that  it  !  been  fulfilled,  that  we  venture  to  predict  for  Dr. 
would  have  a  "  permanent  place  in  the  literature  of  Gross's  treatise  a  permanent  place  in  the  literature 
surgery  worthy  to  rank  with  the  best  works  of  the  of  surgery,  worthy  to  rank  with  the  best  works  of 
present  age."  This  prediction  has  been  amply  ful-  i  the  present  age.  Not  merely  is  the  matter  good, 
filled.  l)r.  Gross's  treatise  h;is  been  found  to  sup-  i  but  the  getting  up  of  the  volume  is  most  creditable 
ply  completely  the  want  which  has  been  felt  ever  '  to  transatlantic  enterprise;  the  paper  and  print 
since  the  elevation  of  surgery  to  the  rnnk  of  science,  would  do  creel  it  to  a  first-rate  London  establishment  ; 
t>f  a  good  practical  treatise  on  the  diseases  of  the  ;  and  the  numerous  wood-cuts  which  illustrate  it,  de- 
'ibuUer  and  its  accessory  organs.  Philos  iphical  in  :  monstrate  that  America  is  makin.;  rapid  advances  in 
its  design,  methodical  in  its  arrangement,  ample  and  this  department  of  art.  We  have,  indeed,  unfeigned 
<•.  ii'ul  in  its  practical  details,  it  may  in  truth  he  said  pleasure  in  congratulating  all  concerned  in  this  pub- 
tolvave  scarcely  anything  to  be  desired  on  so  im-  ;  lication,'  on  the  result  of  their  labours;  and  expe- 
portnnt  a  subject,  and  with  the  additions  and  modi-  rienec  a  feeling  something  like  what  animates  a  long- 
licatinns  resulting  from  future  discoveries  and  im-  expeeranthu8bandman,who,offentimesdisappointed 
provernents,  it  will  probably  remain  one  of  the  most  by  the  produce  of  a  favorite  field,  is  at  l.'ist  agree- 
vnluable  works  on  this  subject  so  long  as  the  science  !  ably  surprised  by  a  stately  crop  which  may  bear 
of  medicine  shall  exist  —  Boston  Mecl.  and  Surg.  '•  comparison  with  any  of  its  former  rivals.  The 
Journal,  June  7,  1S55.  :  grounds  of  our  high  appreciation  of  the  work  will 

A  volume  replete  with  truths  and  principles  of  the    b,e  "''vious  as  vye  proceed  ;  and  we  doubt  not  that 

utmost  value  in  the  investigation  of  these  diseases.—  !  the  present  facilities  for  obtaining  American  books 

African  Medical  Journal.  Wl11  induce  many  of  our  readers  to  verify  our  re- 

,  •  commendation  by  their  own  perusal  of  it.  —  British 

Dr.   Gross  has  brought  all  his  learning,   expen-    and  Foreign  Medico-Chirurgical  Review. 
ence,  tact,  and  judgment  to  the  task,  and  has  pro-  i      ,„,, 

duced  a  work  worthy  of  his  high  reputation.  Ve  !  Whoever  will  peruse  the  vast  amount  of  valuable 
feel  perfectly  safe  in  recommending  it  to  our  read-  practical  information  it  contains,  and  which  we 
graph  unequalled  in  interest  and  i  have  be.el?  nniible  even  to  notice,  will,  we  think, 
practca  vaue  t,v  any  other  on  the  subject  in 
language.  —  Western  Journal  of  Med.  and  Surg. 

It  has  remained  for  an  American  writer  to  wipe 

BY  THE  SAME  AUTHOR.      (J  list  Issued). 

A  PRACTICAL  TREATISE  ON  FOREIGN  BODIES  IN  THE  AIR-PAS- 

SAGES.     In  one  handsome  octavo  volume,  with  illustrations,    pp.  468. 

A  very  elaborate  work.  It  is  a  complete  summary  a  most  interesting  and  hitherto  a  most  neglected  (!e- 
of  the  whole  subject,  and  will  be  a  useful  book  of  ;  partment  of  surgical  pathology  and  practice.  —  St. 


«rs   us   a    monograph    unequalled  . 

practical  value  t,v  any  other  on  the  subject  in  our    ?Sree  wlth  «?'.tliat  tn(ir?  ls  no  work  m  t!ie  En?llsh 


language  which  can  make  anj'  just  pretensions  to 
be  its  equal. — iV.  Y.  Journal  of  Medicine. 


reference. — British  and  Foreign  Medico-C/iirurg. 


Louis  Med.  and  Surg.  Journal,  May,  JS55. 


Surgical  authors,  isolated  reports  in  medical  pe- 
riodicals and  modern  surgeons  '  blend  their  common 
toil"  to  make  a  book  which  exhausts  the  subject, 


Review. 

A  highly  valuahlebook  of  reference  on  a  most  im- 
portant subject  in    the  practice  of  medicine.     We 

conclude,   by  recommending  it  to  our  renders,  fully  and  must  forever  remain  the  standard  work  on  the 

persuaded  t/iat   its  perusal  will   afford  them   much  management  of  this  accident. — Buffalo  Med.  Journ. 
practi ;al  information  well  conveyed    evidently  de-  \      We  consit,er  ,i,is  work  one  of  the  most  important 

nvec  from  considerable  experience  and  deduced  from  of  the  re(.,,nt  additions  to  practical  surgery.     Con- 

an   ample   collection   of  facts.  —  Dublin  quarterly  tHinir,g   ni|  that  has  been  recorded  relating  to  the 

Journal,  May,  1855.  c,.,ss  »f  ac(    • 


In  this  valuable  monograph  Dr.  Gross  hns  cer- 


nccidents  of   which    it   treats,   admirably 

p  .   ...       arranged  and  systematized,  it  should  find  a  place  in 

fninly  struck  a  new  lead  in  Surgery,  and  i«  entitled     every  medical  library. — Montreal  Med.  Chronicle. 
to  the  credit  of  having  illustrated  and  systematized  I 

BY  THE  SAME  AUTHOR.     (Preparing.) 

A  SYSTEM  OF  SURGERY;  Diagnostic,  Pathological,  Therapeutic,  and  Opera- 

live.     With  very  numerous  engravings  on  wood. 

BY   THE   SAME    AUTHOR. 

ELEMENTS  OF  PATHOLOGICAL  ANATOMY;  illustrated  by  colored  En- 

Cravings,  and  two  hundred  and  fifty  wood-cuts.    Second  edition,  thoroughly  revised  and  greatly 

enlarged.    In  one  very  large  and  handsome  imperial  octavo  volume,  pp.  822. 

We  recommend  it  as  the  most  complete,  and,  on  i  The  colored  engravings  and  wood-cuts  are  exceed- 


t.he  whole,  tlie  least  defective  compilation  on  the 
subject  in  the  English  language.— Brit,  and  For. 
Med.  Journal. 

It    is  altogether  the  most  complete  exposition  of 


ingly  well  executed,  arid  the  entire  getting  upof  the 
work  does  much  credit  to  the  enterprising  publishers. 
We  regard  it  ns  one  of  the  most  valuable  works 
ever  issued  from  the  American  press,  and  it  does 
irrcnt  honor  alike  to  the  author,  and  the  country  of 


Pathological  Anatomy  i,,  our  language  —American  '  ?rcat  ll"nor  alike  to  tne  author,  and  tl 
Journal  of  Medical  Sciences.  his  birth.— N.  Y.  Journal  of  Medicine. 


It  is  the  most  complete  and  useful  systematic  work 


We  commend  it  to  the  attention  of  the  profession 


n  1'uthological  Anatomy  in  the  English  language.  '  ?s  (me  l>f  tne  llest  p*tnnt  up»n  the  subject  on  which 


it  treats. — Southern  Journal  Med.  and  Pharmacy. 


AND    SCIENTIFIC    PUBLICATIONS.  17 

GLUGE  (GOTTLIEB),   M.  D., 

Professor  of  Physiology  and  Pathological  Anatomy  in  the  University  of  Brussels,  &c. 

AN  ATLAS   OF   PATHOLOGICAL   HISTOLOGY.     Translated,  with  Notes 

and  Additions,  by  JOSKPH  LEIDY,  M.  D.,  Professor  of  Anatomy  in  the  University  of  Pennsylva- 
nia. In  one  volume,  very  large  imperial  quarto,  with  three  hundred  and  twenty  figures,  plain 
and  colored,  on  twelve  copperplates. 


This  being,  as  far  as  we  know,  the  only  work  in 
which  pathological  histology  is  separately  treated 
of  in  a  comprehensive  manner,  it  will,  we  think,  for 
this  reason,  he  of  infinite  service  to  those  who  desire 
to  investigate  the  subject  systematically,  and  who 
have  felt  the  difficulty  of  arranging  in  their  mind 


the  unconnected  observations  of  a  great  number  of 
authors.  The  development  of  the  morbid  tissues, 
and  the  formation  of  abnormal  products,  may  now 
be  followed  and  studied  with  the  sume  ease  and 
satisfaction  as  the  best  arranged  system  of  phy- 
siology.— American  Med.  Journal. 


GARDNER  (D.  PEREIRA),  M.  D. 
MEDICAL  CHEMIST KY,  for  the  use  of  Students  and  the  Profession:  being  a 

Manual  of  the  Science,  with  its  Applications  to  Toxicology,  Physiology,  Therapeutics,  Hygiene, 
&c.     In  one  handsome  royal  12mo.  volume,  of  about  400  pages,  with  illustrations. 


HASSE  (C.  E.),   M.  D. 

AN  ANATOMICAL  DESCRIPTION  OF  THE  DISEASES  OF  RESPIRA- 
TION AND  CIRCULATION.     Translated  and  Edited  by  SWA  INK.     In  one  volume,  octavo. 

HARRISON  (JOHN),   M.D. 
AN   ESSAY  TOWARDS  A  CORRECT  THEORY  OF  THE  NERVOUS 

SYSTEM.    In  one  octavo  volume,  292  pages. 

HUNTER  (JOHN). 
TREATISE  ON   THE  VENEREAL  DISEASE.     With  copious  Additions,  by 

DR.  PH.  RICORD,  Surgeon  to  the  Venereal  Hospital  of  Paris.     Edited,  with  additional  Notes,  by 
F.  J.  BESTEAD,  M.  D.     In  one  octavo  volume,  with  plates     (Now  Ready.)    \3JT  See  RICOKD. 
ALSO,  HUNTER'S  COMPLETE  WORKS,  with  Memoir,  Notes,  &c.  &c.    In  four  neat  octavo 
volumes,  with  plates. 

HUGHES   (H.    M.),  M .  D.., 
Assistant  Physician  to  Guy's  Hospital,  &c. 

A  CLINICAL  INTRODUCTION  TO  THE   PRACTICE   OF  AUSCULTA- 

TION,  and  other  Modes  of  Physical  Diagnosis,  in  Diseases  of  the  Lungs  and  Heart.     Second 
American  from  the  Second  and  Improved  London  Edition.  In  one  royal  ]2mo.  vol.  pp.  30-4. 
It  has  been  carefully  revised  throughout.     Some  small  portions  have  been  erased ;  much  has 
been,  I  trust,  amended;  and  a  great  deal  of  new  matter  has  been  added;  so  that,  though  funda- 
mentally it  is  the  same  book,  it  is  in  many  respects  a  new  work. — Preface. 

HORNER  (WILLIAM  E.),  M.  D., 

Professor  of  Anatomy  in  the  University  of  Pennsylvania. 

SPECIAL    ANATOMY    AND    HISTOLOGY.     Eighth  edition.     Extensively 

revised  and  modified.     In  two  large  octavo  volumes,  of  more  than  one  thousand  pages,  hand- 
somely printed,  with  over  three  hundred  illustrations. 

This  work  has  enjoyed  a  thorough  and  laborious  revision  on  the  part  of  the  author,  with  the 
view  of  bringing  it  fully  up  to  the  existing  state  of  knowledge  on  the  subject  of  general  and  special 
anatomy.  To  adapt  it  more  perfectly  to  the  wants  of  the  student,  he  has  introduced  a  large  number 
of  additional  wood-engravings,  illustrative  of  the  objects  described,  while  the  publishers  have  en- 
deavored to  render  the  mechanical  execution  of  the  work  worthy  of  the  extended  reputation  which 
it  has  acquired.  The  demand  which  has  carried  it  to  an  EIGHTH  EDITION  is  a  sufficient  evi- 
dence of  the  value  of  the  work,  and  oi  its  adaptation  to  the  wants  of  the  student  and  professional 
reader. 

HOBLYN  (RICHARD  D.),  A.  M . 
A  DICTIONARY  OF  THE  TERMS  USED  IN  MEDICINE  AND  THE 

COLLATERAL   SCIENCES.     New  and  much  improved  American  Edition.     Revised,  with 
numerous  Additions,  from  the  last  London  edition,  by  ISAAC  HAYS,  M.  D.,  &c.     In  one  large 
royal  12mo.  volume,  of  over  four  hundred  pages,  double  columns.     (Now  Ready.) 
In  passing  this  work  a  second  time  through  the  press,  the  editor  has  subjected  it  to  a  very  tho- 
rough revision,  making  such  additions  as  the  progress  of  science  has  rendered  desirable,  and  snp- 
plying  any  omissions  that  may  have  previously  existed.     As  a  concise  and  convenient  Dictionary 
of  Medical  Terms,  at  an  exceedingly  low  price,  it  will  therefore  be  found  of  great  value  to  the  stu- 
dent and  practitioner. 

JONES  (T.   WHARTON),   F.  R.  S.,  &c. 
THE  PRINCIPLES  AND  PRACTICE  OF   OPHTHALMIC    MEDICINE 

AND  SURGERY.    Edited  by  ISAAC  HAYS,  M.  D.,  &c.     In  one  very  neat  volume,  large  royal 
12mo.,  of  529  pages,  with  four  plates,  plain  or  colored,  and  ninety-eight  wood-cuts. 


The  work  amply  sustains,  in  every  point  the  al- 
ready high  reputation  of  the  author  as  an  ophthalmic 
surgeon  as  well  as  a  physiologist  and  pathologist. 
The  book  is  evidently  the  result  of  much  labor  and 
research,  and  has  been  written  with  the  greatest 
care  and  attention.  We  entertain  little  doubi  that 
this  book  will  become  what  its  author  hoped  it 


might  become,  a  manual  for  daily  reference  and 
consultation  by  the  student  and  the  general  practi- 
tioner. The  work  is  marked  by  that  correctness, 
clearness,  and  precision  of  style  which  distinguish 
all  the  productions  of  the  learned  author. — British 
and  Foreign  Medical  Review. 


18 


BLANCHARD    &    LEA'S    MEDICAL 


JONES  (C.    HANDHELD),  F.  R.  S.,  &.   EDWARD   H.   SIEVEKING,   M.D., 

Assistant  Physicians  and  Lecturers  in  St.  Mary's  Hospital,  London. 

A  MANUAL  OF  PATHOLOGICAL   ANATOMY.     First  American  Edition, 

Revised.     With  Iliree  hundred  and  ninety-seven  handsome  wood  engravings.     In  one  large  and 
beautiful  octavo  volume  of  nearly  seven  hundred  and  fifty  pages.     (Just  Issued.) 

In  a  work  like  the  present,  intended  as  a  text-book  for  the  student  of  pathology,  accurate  engrav- 
ings of  the  various  results  of  morbid  action  are  of  the  greatest  assistance.  The  American  pub- 
lishers have,  therefore,  considered  that  the  value  of  the  work  might  lie  enhanced  by  increasing  the 
number  of  illustrations,  and,  with  this  object,  many  wood-cuts,  from  the  best  authorities,  have  been 
introduced,  increasing  the  number  from  one  hundred  and  sixty-seven,  in  the  London  Edition,  to 
three  hundred  and  ninety-seven  in  this.  The  selection  of  these  wood-cuts  has  been  made  by  a 
competent  member  of  the  profession,  who  has  supervised  the  progress  of  the  work  through  the 
pi-ess,  with  the  view  of  securing  an  accurate  reprint,  and  of  correcting  such  errors  as  had  escaped 
the  attention  of  the  authors. 

With  these  improvements,  the  volume  is  therefore  presented  in  the  hope  of  supplying  the  ac- 
knowledged want  of  a  work  which,  within  a  moderate  compass,  should  embody  a  condensed  and 
accurate  digest  of  the  present  state  of  pathological  science,  as  extended  by  recent  microscopical, 
chemical,  and  physiological  researches. 

As  a  concise  text-book,  containing,  in  a  condensed  '  authors  have  not  attempted  to  intrude  new  views  on 
form,  a  complete  outline  of  what  is  known  in  the  their  professional  brethren,  but  simply  to  lay  before 
domain  of  Pathological  Anatomy,  it  is  perhaps  the  i  them,  what  has  long  been  wanted,  an  outline  of  the 
best  work  in  ihe  English  language.  Its  great  merit  \  present  condition  of  pathological  anatomy.  In  this 
consists  in  its  completeness  and  brevity,  and  in  this  |  they  have  been  completely  successful.  The  work  is 
respect  it  supplies  a  great  desideratum  in  our  lite-  one  of  the  best  compilations  which  we  have  ever 
raturc.  Heretofore  the  student  of  pathology  was  !  perused.  The  opinions  and  discoveries  of  all  the 
obliged  to  glean  from  a  great  number  of  monographs,  |  leading  pathologistsand  physiologists  a  re  engrossed, 
and  the  field  was  so  extensive  that  !>ut  few  cultivated  |  so  that  by  reading  any  subject  treated  in  the  book 
it  with  any  degree  of  success.  The  authors  of  the  '  you  have  a  synopsis  of  the  views  of  the  most  ap- 
present  work  have  sought  to  corrrct  this  defect  by  j  proved  authors. — Charleston  Medical  Journal  and 
placing  before  the  reader  a  summary  of  ascertained  '  Review. 


facts,  together  witli  the  opinions  of  the  most  eminent 
pathologists  both  of  the  Old  and  New  World.    As  a 


We  have  no  hesitation  in   recommending   it  as 
worthy  of  careful  and  thorough  study  by  every  mem- 


siinple  work  of  reference,  therefore,  it,  is  of  great  j  ber  ,/,,,„  profess'ion,  old,  or  young.— tf.  W.  Med. 
value  to  the  student  of  pathological  anatomy,  and  j  and  Surg_  JournaL 
should   be  in   every  physician's  library. —  Western  \ 

Lancet.  From  the  casual  examination  we  have  given  we 

are  inclined  to  regard  it  as  n  text-book,  plain,  ra- 

A\e  urge  upon  our  readers  and  the  profession  gene-     tional   and  intelligible,  such  a  book  as  the  practical 

rally  the  importance  of  informing  themselves  in  re-  !  man  neecls  for  dal|y  reference.     For  this  reason  it 

gard  to  modern  views  of  pathology,  and  recommend    will  be  like|y  to  be  ianrely  useful,  as  it  suits  itself 

to  them  to  procure  the  work  before  us  as  the  best!  to  those  busy  men  who  have  little  time  for  minute 

f  obtaining  this  information.— Stethoscope,     j  investigation,  and  prefer  a  summary  to  an  elaborate 

In  offering  the  above  titled  work  to  the  public,  the  1  treatise.— Buffalo  Medical  Journal. 


•KIRKES  (WILLIAM   SENHOUSE),    M.  D., 

Demonstrator  of  Morbid  Anatomy  at  St.  Bartholomew's  Hospital,  &c.;  and 

JAMES   PAGET,  F.  R.  S., 

Lecturer  on  General  Anatomy  and  Physiology  in  St.  Bartholomew's  Hospital. 

A    MANUAL    OF    PHYSIOLOGY.     Second  American,  from  the  second  and 

improved  London  edition.    With  one  hundred  and  sixty-five  illustrations.     In  one  large  and 
handsome  royal  12mo.  volume,     pp.  550.     (Jkist  Issued.) 

In  the  present  edition,  the  Manual  of  Physiology     the  practitioner  who  has  but  leisure  to  refresh  his 
ns  been  brought  up  to  the  actual  condition  of  the     memory,  this  book  is  invaluable,  as  it  contains  all 


science,  and  fully  sustains  the  reputation  which  it 
has  already  so  deservedly  attained.  We  consider 
the  work  of  MM.  Kirkes  and  Paget  to  constitute  one 
of  the  very  best  handbooks  of  Physiology  we  possess 
— presenting  just  such  an  outline  of  the  science,  com- 
prising an  account  of  its  leading  facts  and  generally 
admitted  principles,  as  the  student  requires  during 
his  attendance  upon  a  course  of  lectures,  or  for  re- 
ference whilst  preparing  for  examination. —  Am. 
Medical  Journal . 

We  need  only  say,  that,  without  entering  into  dis- 
cussions of  unsettled  questions,  it  contains  all  the 
recent  improvements  in  this  department,  of  medical 
science.  For  the  student  beginning  this  study,  and 


that  it  is  important  to  know,  without  special  details, 
which  are  read  with  interest  only  by  those  who 
would  make  a  specialty,  or  desire  to  possess  a  criti- 
cal knowledge  of  the  subject. — Charleston  Medical 
Journal. 

One  of  the  best  treatises  that  can  be  put  into  the 
hands  of  the  student. — London  Medical  Gazette. 

Particularly  adapted  to  those  who  desire  to  pos- 
sess a  concise  digest  of  the  facts  of  Human  Physi- 
ology.— British  and  Foreign  Med.-Chirurg.  Review. 

We  conscientiously  recommend  it  as  an  admira- 
ble "  Handbook  of  Physiology."— London  Journal 
of  Medicine, 


KNAPP  (F.),  PH.  D.,  &.c. 
TECHNOLOGY ;  or,  Chemistry  applied  to  the  Arts  and  to  Manufactures.    Edited, 

with  numerous  Notes  and  Additions,  by  Dr.  EDMUND  RONALDS  and  Dr.  THOMAS  RICHARDSON. 
First  American  edition,  with  Notes  and  Additions,  by  Prof.  WALTER  R.  JOHNSON.  In  two  hand- 
some octavo  volumes,  printed  and  illustrated  in  the  highest  style  of  art,  with  about  five  hundred 
wood-engravings. 


LONGET   (F.  A.) 

TREATISE  ON  PHYSIOLOGY.  With  numerous  Illustrations.  Translated 
from  the  French  by  F.  G.  Smith,  M.  D.,  Professor  of  Institutes  of  Medicine  in  the  Pennsylvania 
Medical  College,  (Preparing.) 


AND    SCIENTIFIC    PUBLICATIONS.  19 

LEHMANN    (G.   C.) 
PHYSIOLOGICAL    CHEMISTRY.      Translated  by  GEORGE  E.  DAT,  M.  D., 

and  edited  by  Prof.  R.  E.  ROGERS,  of  the  University  of  Pennsylvania.    In  two  large  octavo 
volumes,  with  handsome  illustrations.     (Nearly  Ready.) 

This  great  work,  universally  recognized  as  the  most  complete  and  authoritative  exposition  of  its 
intricate  and  important  subject  in  its  most  advanced  Condition,  will  receive  every  care  tlurii 
passage  through  the  press,  under  the  superintendence  of  Prof.  Rogers,  to  insure  the  entire  uccuracy 
indispensable  to  a  work  of  this  character.  It  will  be  further  improved  by  the  distribution  in  the 
appropriate  places  throughout  the  text  of  the  numerou*  additions  and  corrections  embodied  in  the 
Appendix,  while  a  number  of  illustrations  will  be  introduced  from  "  Funke's  Atlas  of  Physiological 
Chemistry."  The  publishers,  therefore,  trust  that  it  will  be  found  a  complete  and  accurate  edition, 
and  in  every  respect  worthy  of  the  reputation  of  the  work. 

The  progress  of  research  in  this  department  is  so  and  exact  view  of  its  present  aspect,  should  lose  no 

rapid,  that   Prof.    Lchmann's   treatise  must  he  re-  time  in  attaching  themselves  to  the  Society  by  which 

yarded   as    having    completely   superseded   that   of  it  is  in  course  of  publication. — British  and  Foreign 

Simon;  anil  iill  who  desire  to  possess  a  systematic  Medico-Ckirurgical  Review. 

work  on   "in-Biological  Chemistry  by  a  man  who  is        The  work  of  Lehm!lnn  8tands  unrival]ed   as   the 

thoroughly  qualified,  both  by  his  physiological  and  mO8t  (SrnnrfreheDSjVe  book  of  reference  and  informa- 

cheimcal  Bcqairements,  by  his  own  eminence  as  an  tion  cxtill|t  on  every  branch  of  the  subject  on  which 

experimentalist,  and  by  the  philosophic  impartiality  lt  treats.- JMm6«rff  Monthly  Journal  of  Medical 

of  las  habits  of  thought,  to  afford  a  comprenensive  science 


LAWRENCE  (W.),   F.  R.  S.,  &c. 
A  TREATISE    ON    DISEASES    OF    THE    EYE.     A    new  edition,   edited, 

with  numerous  additions,  and  243  illustrations,  by  ISAAC  HAYS,  M.  D.,  Surgeon  to  Wills  Hospi- 
tal, &c.  In  one  very  large  and  handsome  octavo  volume,  oi"950  pages,  strongly  bound  in  leather 
with  raised  bands.  (Lately  Ignited.)  • 

This  work  is  so  universally  recognized  as  the  standard  authority  on  the  subject,  that  the  pub- 
lishers in  presenting  this  new  edition  have  only  to  remark  that  in  its  preparation  the  editor  has 
carefully  revised  every  portion,  introducing  additions  and  illustrations  wherever  the  advance  of 
science  has  rendered  them  necessary  or  desirable.  In  this  manner  it  will  be  found  to  cpn- 
tain  over  one  hundred  pages  more  than  the  last  edition,  while  the  list  of  wood-engravings 
has  been  increased  by  sixty-seven  figures,  besides  numerous  improved  illustrations  substituted 
for  such  as  were  deemed  imperfect  or  unsatisfactory.  The  various  important  contributions  to 
ophthalmologic.il  science,  recently  made  by  Dalrymple,  Jacob,  Walton,  Wilde,  Cooper,  &c., 
both  in  the  form  of  separate  treatises  and  contributions  to  periodicals,  have  been  carefully 
examined  by  the  editor,  and,  combined  with  the  results  of  his  own  experience,  have  been 
freely  introduced  throughout  the  volume,  rendering  it  a  complete  and  thorough  exponent  of 
the  most  advanced  state  of  the  subject. 

In  a  future  number  we  shall  notice  more  at  length  octavo  pages- has  enabled  both  author  and  editor  to 
this  admirahle  treatise -the  safest  guide  and  most  do  justice  to  all  the  details  of  this  sutiject,  and  crn- 
comprehensive  work  of  reference,  which  is  within  dense  in  this  single  volume  the  present  state  or"  our 
the  reacli  of  all  classes  of  the  profession. — Stetko-  knowledge  of  the  whole  science  in  this  department, 
scope,  March,  1854.  i  whereby  its  practical  value  cannot  be  excelled.  We 

|  heartily  commend  it,  especially  as  a  book  of  refe- 

This  standard  text-book  on  the  department  of  :  rence,  indispensable  in  every  medical  library.  The 
which  it  treats,  has  not  been  superseded,  by  any  or  additions  of  the  American  editor  very  greatly  en- 
all  of  the  numerous  publications  on  the  subject  ,  hance  the  value  of  the  work,  exhibiting  the  learning 
heretofore  issued.  Nor  with  the  multiplied  improve-  ;  and  experience  of  Dr.  Hays,  in  the  light  in  which  he 
inents  of  Dr.  Hays,  the  American  editor,  is  it  at  all  ought  to  be  held,  as  a  standard  authority  on  all  sub- 
likely  that  this  great  work  will  cease  to  merit  the  jects  appertaining  to  this  specialty,  to  which  he  has 
confidence  and  preference  of  students  or  practition-  j  rendered  so  many  valuable  contributions. — N.  Y. 
era.  Its  ample  extent — nearly  one  thousand  large  1  Medical  Gazette. 


LEE  (ROBERT),   M .  D.,  F.  R.  S.,  &c. 
CLINICAL    MIDWIFERY;    comprising  the   Histories  of  Five  Hundred  and 

Forty-five  Cases  of  Difficult,  Preternatural,  and  Complicated  Labor,  with  Commentaries.  From 
the  second  London  edition.  In  one  royal  12mo.  volume,  extra  cloth,  of  238  pages. 

LUDLOW    (J.    L.),    M.  D., 
Lecturer  on  Clinical  Medicine  at  the  Philadelphia  Almshouse,  &c. 

A  MANUAL  OF  EXAMINATIONS  upon  Anatomy  and  Physiology,  Surgery, 

Practice  of  Medicine,  Chemistry,  Obstetrics,  Materia  Medica,  Pharmacy,  and  Therapeutics. 
Designed  for  Students  of  Medicine  throughout  the  United  States.  A  new  edition,  revised  and 
extensively  improved.  In  one  large  royal  12mo.  volume,  with  several  hundred  illustrations. 
(Preparing.) 

LISTON  (ROBERT),   F.  R.  S.,  &c. 
LECTURES  ON  THE  OPERATIONS  OF  SURGERY,  and  on  Diseases  and 

Accidents  requiring  Operations.  Edited,  with  numerous  Additions  and  Alterations,  by  T.  D. 
MUTTER,  M.  D.  In  one  large  and  handsome  octavo  volume,  of  566  pages,  with  216  wood-cuts. 

LALLEMAND  (M.). 

THE    CAUSES,    SYMPTOMS,    AND    TREATMENT    OF    SPERMATOR- 

RHCEA.  Translated  and  edited  by  HENRY  J.  McDouGAL.  In  one  volume,  octavo,  320  pages. 
Second  American  edition.  (Just  Issued.) 


•JO 


BLANCHARD    &    LEA'S    MEDICAL 


LA   ROCHE   (FU,    M.  D.,  &c. 

PNEUMONIA ;  its  Supposed  Connection,  Pathological  and  Etiological,  with  Au- 
tumnal Fever:-,  including-  an  Inquiry  into  the  Existence  and  Morbid  Agency  of  Malaria.  In  one 
handsome  octavo  volume,  extra  cloth,  of  000  pages. 


A  more  simple,  clear,  and  forcible  exposition  of  , 
the  groundless  nature  and   dangerous   tendency  of  i 
certain   pathological   nnd  etiological    heresies,  has 
seldom  been  presented  to  our  notice. — N.  Y.  Journal 
of  Medicine  and  Collateral  Science. 

This  work  should  be  carefully  studied  by  Southern 
physicians,  embodying  as  it  does  the  reflections  of 
an  original  thinker  and  close  observer  on  a  subject 
peculiarly  their  own. —  Virginia  Med.  a/id  Surgical 
Journal. 

The  author  had  prepared  us  to  expect  a  treatise 
from  him,  by  his  brief  papers  on  kindred  topics  in 


the  periodical  press,  and  yet  in  the  work  before  us 
he  has  exhibited  an  amount  of  industry  »nd  learning, 
research  and  ability,  beyond  what  we  are  accustomed 
to  discover  in  modern  medical  writers;  while  his 
own  extensive  opportunities  for  observation  and 
experience  have  been  improved  by  the  most  laudable 
diligence,  and  display  a  familiarity  with  the  whole 
subject  in  every  aspect,  which  commands  both  our 
respect  and  confidence.  As  a  corrective  of  prevail  sit 
and  mischievous  error,  sought  to  be  propagated  by 
novices  and  innovators,  we  could  wish  that  Dr.  La 
Roche's  book  could  be  widely  read. — N.  Y.  Medical 
Gazette. 


BY  THE  SAME  AUTHOR.      (Now  Ready.) 

YELLOW  FEVER,  considered  in  its  Historical,  Pathological,  Etiological,  and 

Therapeutical  Relations.  Including  a  Sketch  of  the  Disease  a*  it  has  occurred  in  Philadelphia 
from  1 099  to  185-4,  with  an  examination  of  the  connections  between  it  and  the  fevers  known  under 
the  same  name  in  other  parts  of  temperate  as  well  as  in  tropical  regions.  In  two  large  and 
handsome  octavo  volumes  of  nearly  1500  pages. 

The  publishers  are  happy  in  being  able  to  announce  the  appearance  of  this  great  work. 
As  the  result  of  many  years  of  study  and  observation,  and  as  acorn  plete  resume  of  all  that  has  been 
•written  on  the  subject,  it  will  at  once  take  its  place  as  the  standard  authority  and  work  of  reference 
on  the  important  questions  brought  under  consideration.  • 


LARDNER  (DIONYSIUS),   D.  C.  L.,  &c. 
HANDBOOKS    OF    NATUEAL    PHILOSOPHY    AND 


ASTRONOMY. 


Revised,  with  numerous  Additions,  by  the  American  editor.  FIRST  COURSE,  containing  Mecha- 
nics, Hydrostatics,  Hydraulics,  Pneumatics,  Sound,  and  Optics.  In  one  large  royal  12rno. 
volume,  of  750  pages,  with  424  wood-cuts.  SECOND  COURSE,  containing  Heat,  Electricity,  Mag- 
netism, and  Galvanism,  one  volume,  large  royal  12mo.,  of  450  pages,  with  250  illustrations. 
THIRD  COURSE  (  now  ready),  containing  Meteorology  and  Astronomy,  in  one  large  volume,  royal 
12mo.  of  nearly  eight  hundred  pages,  with  thirty-seven  plates  and  two  hundred  wood-cuts.  The 
whole  complete  in  three  volumes,  of  about  two  thousand  large  pages,  with  over  one  thousand 
figures  on  steel  and  wood.  Any  volume  sold  separate. 
The  various  sciences  treated  in  this  work  will  be  found  brought  thoroughly  up  to  the  latest  period. 


MACKENZIE   (W.),    M.D., 

Surgeon  Oculist  in  Scotland  in  ordinary  to  Her  Majesty,  &c.  &c. 

A  PRACTICAL   TREATISE  ON   DISEASES    AND  INJURIES  OF   THE 

EYE.  To  which  is  prefixed  an  Anatomical  Introduction  explanatory  of  a  Horizontal  Section  of 
the  Human  Eyeball,  by  THOMAS  WHARTON  JONES,  F.  R.  S.  From  the  Fourth  Revised  and  En- 
lars-ed  London  Edition.  With  Notes  and  Additions  by  ADDINELL  HEWSON,  M.  D-,  Surgeon  vo 
Wills  Hospital,  &c.  <fcc.  In  one  very  large  and  handsome  octavo  volume,  with  plates  and  numerous 
•wood-cuts.  (Now  Ready.) 

The  reputation  which  this  work  has  universally  attained  will  te  enhanced  by  the  present  edition. 
Besides  the  thorough  revision  by  the  author  which  it  has  enjoyed  in  recently  passing  through  the 
press  in  London,  the  additions  by  the  editor  embrace  whatever  is  necessary  to  adapt  it  com- 
pletely to  the  wants  of  the  American  practitioner,  constituting  it  a  library  of  Ophthalmic  Medicine 
and  Surgery. 

The  treatise  of  Dr.  Mackenzie  indisputably  holds  1  accordance  with  the  advances  in  the  science  which 


the  first  place,  and  forms,  in  respect  of  learning  and 
research,  an  Encyclopaedia  unequalled  in  extent  by 


have  been  made  of  late  years.    Nothing  worthy  of 
repetition  upon  any  branch  of  the  subject  appears  to 


any  other  work  of  the  kind, either  English  orforeign.  :  have  escaped  the  author's  notice.    We  consider  it 
— Dixon  on  Diseases  of  the  Eye.  !  the  duty  of  every  one  who  has  the  love  of  his  profes- 

'  sion  and  the  welfare  of  his  patient  at  heai  t,  to  make 


it  displayed,  the  thorough  acquaintance  with  the 
subject,  practically  as  well  as  theoretically. and  the 
able  manner  in  which  the  author's  stores  of  learning 
and  experience  were  rendered  available  for  general 
use,  at  once  procured  for  the  first  edition,  as  well  on 
the  continent  as  in  this  country,  that  high  position 
as  a  standard  work  which  each  successive  edition 
has  more  firmly  established,  in  spite  of  the  attrac- 
tions of  several  rivals  of  no  mean  ability.  This,  the 
fourth  edition,  has  been  in  a  great  measure  re-writ- 
ten ;  new  matter,  to  the  extent  of  one  hundred  and 
fifty  pages,  has  been  added,  and  in  several  instances 


The  fourth  edition  of  this  standard  work  will  no 
doubt  be  as  fully  appreciated  as  the  three  former  edi- 
tions. It  is  unnecessary  to  say  a  word  in  its  praise, 
for  the  verdict  has  already  been  passed  upon  it  by 
the  most  competent  judges,  and  u  Mackenzie  on  the 
Kye"  has  justly  obtained  a  reputation  which  it  is 
no  figure  of  speech  to  call  world-wide. — British  and 
Foreign  Medico-Chirurgical  Review. 

This  new  edition  i.f  Dr.  Mackenzie's  celebrated 
treatise  on  diseases  of  the  eye,  is  truly  a  miracle  of 
industry  and  learning.  We  need  scarcely  say  that 
he  has  entirely  exhausted  the  subject  of  his  specialty. 


formerly  expressed  opinions  have  been  modified  in    — Dublin  Quarterly  Journal. 


AND    SCIENTIFIC    PUBLICATIONS. 


21 


MEIGS  (CHARLES  D.),  M.  D., 
Professor  of  Obstetrics,  &c.  in  the  Jefferson  Medical  College.  Philadelphia. 

ON    THE    NATURE,     SIGNS,    AND    TREATMENT    OF    CHILDBED 

FEVEft.     In   a  Series  of  Letters  addressed  to  the  Students  of  his  Class.     In  one  handsome 

octavo  volume,  of  three  hundred  and  sixty-five  pages.    (Now  Ready.) 

The  instructive  nnd   interesting   author   of  this  I      This  book  will  add  more  to  his  fame  th:m  either 


of  those  which  bear  his  mime.  Indeed  we  doulit 
whether  any  material  improvement  will  be  made  on 
the  teachings  of  this  volume  for  a  century  to  come, 
since  it  is  so  eminently  practical,  and  based  on  pro- 
found knowledge  of  the  science  and  consummate 
skill  in  the  nrt  of  healing,  and  ratified  by  an  ample 
and  extensive  experience,  sucli  as  few  men  have  the 
industry  or  good  fortune  to  acquire. — IV.  Y.  Med. 
Gazette, 


work,  whose  previous  labors  in  the  department  <f 
medicine  which  lie  so  sedulously  cultivates,  have 
placed  his  countrymen  under  deep  and  abiding  obli- 
gations, again  challenges  their  admiration  in  the 
fresh  ami  vigorous,  attractive  and  racy  pages  before 
us.  It  is  a  delectable  book.  *  *  *  This  treatise 
up'in  child-bed  fevers  will  have  an  extensive  sale, 
being  destined,  as  it  deserves,  to  find  a  place  in  the 
library  of  every  practitioner  who  scorns  to  lag  in  the 
rear  of  his  bret.'iren. — Nashville  Journal  of  Medi- 
tine  and  Surgery. 

BY   THE   SAME   AUTHOR. 

WOMAN:  HER  DISEASES  AND  THEIR  REMEDIES.     A  Series  of  Lee- 

lures  to  his  Class.     Third  and  Improved  edition.     In  one  large  and  beautifully  printed  octavo 

volume.     (Just  Issued.)     pp.  672. 

The  gratifyin?  appreciation  of  his  labor?,  as  evinced  by  the  exhaustion  of  two  large  impressions 
cW'  this  work  within  a  few  years,  has  not  been  lost  upon  the  author,  who  has  endeavored  in  every 
way  to  render  it  worthy  of  the  favor  with  which  it  has  been  received.  The  opportunity  thus 
afforded  fora  second  revision  has  been  improved,  and  the  work  is  now  presented  as  in  every  way 
superior  to  ils  predecessors,  additions  and  alterations  having  been  made  whenever  the  advance  of 
science  has  rendered  them  desirable.  The  typographical  execution  of  the  work  will  also  be  found 
to  have  undergone  a  similar  improvement  and  the  work  is  now  confidently  presented  as  in  every 
way  worthy  the  position  it  has  acquired  as  the  standard  American  texl-book  ou  the  Diseases  ol 
Females. 

It  contains  a  v;ist  amount  of  practical  knowledge,  I  such  bold  relief,  as  to  produce  distinct  impressions 
by  one  who  has  accurately  observed  and  retained  I  upon  the  mind  and  memory  of  the  reader.  —  The 
the,  experience  of  n.any  years,  and  who  tells  the  re-  i  Charleston  Med.  Journal. 

s.itt  in  a  free,  familiar,  and  pleasant  manner.— Dub-  I      Profess()r   Meigs   has  enlarged  and  amended  this 
I, n  Quarterly  Journal.  !  great  work,  for  such  it   unquestionably  is,  having 

There  is  an  off-hand  fervor,  a  glow,  nnd  a  warm-  passed  the  ordeal  of  criticism  at  home  and  abroad, 
heartedness  infecting  the  effort  of  Dr.  Meigs,  which  but  been  improved  thereby  J  for  in  this  new  edition 
is  entirely  captivating,  and  which  absolutely  hur-  the  author  has  introduced  real  improvements,  and 
ries  the  reader  through  from  beginning  to  end.  Be-  i  increased  the  value  and  utility  of  the  book  im- 


sides,  the  book  teems  with  solid  instruction,  and 
it  shows  the  very  highest  evidence  of  ability,  viz., 
the  clearness  with  which  the  information  is  pre- 
sented. \Ve  know  of  no  better  test  of  one's  under- 
standing a  subject  than  the  evidence  of  the  pfjwer 


measurably.  It  presents  so  many  novel,  bright, 
and  sparkling  thoughts;  such  an  exuberance  of  new 
ideas  on  almost  every  page,  that  we  confess  our- 
selves to  have  become  enamored  with  the  book 
and  its  author ;  and  cannot  withhold  our  congratu- 


mling  a 

of  lucidly  explaining  it.     The  most  elementary,  as  j  lations  from  our  Philadelphia  confreres,  that  such  a 
well  as  the  obscurest  subjects,  under  the  pencil  of    teacher  is  in  their  service. — JV.  If.  Med.  Gazette. 
Prof.  Meigs,  are  isolated  and  made  to  stand  out  in  | 

BY   THE  SAME   AUTHOR. 

OBSTETRICS:  THE  SCIENCE  AND   THE   ART.     Second  edition,  revised 

and  improved.     With  one  hundred  and  thirty-one  illustrations.     In  one  beautifully  printed  octavo 
volume,  of  seven  hundred  and  fifty-two  large  pages.     (Lately  Publislwd.) 

The  rapid  demand  for  a  second  edition  of  this  work  is  a  sufficient  evidence  that  it  has  supplied 
a  desideratum  of  the  profession,  notwithstanding  the  numerous  treatises  on  the  same  subject  which 
have  appeared  within  the  last  few  years.  Adopting  a  system  of  his  own,  the  author  has  combined 
the  leading  principles  of  his  interesting  and  diificult  subject,  with  a  thorough  exposition  of  its  rules 
of  practice,  presenting  the  results  of  long  and  extensive  experience  and  of  familiar  acquaintance 
with  all  the  modern  writers  on  this  department  of  medicine.  As  an  American  Treati:-e  on  Mid- 
wifery, which  has  at  once  assumed  the  position  of  a  classic,  it  possesses  peculiar  claims  to  the  at- 
tention and  study  of  the  practitioner  and  student,  while  the  numerous  alterations  and  revisions 
which  it  has  undergone  in  the  present  edition  are  shown  by  the  great  enlargement  of  the  work, 
which  is  not  only  increased  as  to  the  size  of  the  page,  but  also  in  the  number. 

BY  THE  SAME  AUTHOR.     (Now  Ready.) 

A  TREATISE  ON  ACUTE  AND  CHRONIC  DISEASES  OF  THE  NECK 

OF  THE  UTERUS.     With  numerous  plates,  drawn  and  colored  from  nature  iu  the  highest 
style  of  art.    In  one  handsome  octavo  volume,  extra  cloth. 

The  object  of  the  author  in  this  work  has  been  to  present  in  a  small  compass  the  practical  results 
of  hi*  long  experience  in  this  important  and  distressing  class  of  diseases.  The  great  changes  intro- 
duced into  practice,  and  the  acce^sions  to  our  knowledge  on  the  subject,  writhin  the  last  few  years, 
re.-ulting  from  the  use  of  the  metroscope,  brings  within  the  ordinary  practice  of  every  physician 
numerous  cases  which  were  formerly  regarded  as  incurable,  and  renders  of  great  value  a  work  like 
the  present  combining  practical  directions  for  diagnosis  and  treatment  with  an  ample  series  of  illus- 
trations, copied  accurately  from  colored  drawings  made  by  the  author,  after  nature. 


BY   THE   SAME   AUTHOR. 

OBSERVATIONS   ON    CERTAIN    OF    THE    DISEASES 

CHILDREN.    In  one  handsome  octavo  volume,  of  214  pages. 


OF    YOUNG 


22 


MACLISE   (JOSEPH),    SURGEON. 
SURGICAL   ANATOMY.     Forming   one  volume,   very  large   imperial   quarto. 

With  sixty-eight  large  and  splendid  Plates,  drawn  in  the  best  style  and  beautifully  colored.  Con- 
taining one  hundred  and  ninety  Figures,  many  of  them  the  size  of  life.  Together  with  copious 
and  explanatory  letter-press.  Strongly  and  handsomely  bound  in  extra  cloth,  being  one  of  the 
cheapest  and  best  executed  Surgica  works  as  yet  issued  in  this  country. 

Copies  can  be  sent  by  mail,  in.  five  parts,  done  up  in  stout  covers. 

This  great  work  being  now  concluded,  the  publishers  confidently  present  it  to  the  attention  of  the 
profession  as  worthy  in  every  respect  of  their  approbation  and  patronage.  No  complete  work  ol 
the  kind  has  yet  been  published  in  the  English  language,  and  it  therefore  will  supply  a  want  long 
felt  in  this  country  of  an  accurate  and  comprehensive  Atlas  of  Surgical  Anatomy  to  which  the 
student  and  practitioner  can  at  all  times  refer,  to  ascertain  the  exact  relative  position  of  the  various 
portions  of  the  human  frame  towards  each  other  and  to  the  surface,  as  well  as  their  abnormal  de- 
viations. The  importance  of  such  a  work  to  the  student  in  the  absence  of  anatomical  material,  and 
to  the  practitioner  when  about  attempting  an  operation,  is  evident,  while  the  price  of  the  book,  not- 
withstanding the  large  size,  beauty,  and  finish  of  the  very  numerous  illustrations,  is  so  low  as  to 
place  it  within  the  reach  of  every  member  of  the  profession.  The  publishers  therefore  confidently 
anticipate  a  very  extended  circulation  for  this  magnificent  work. 


One  of  the  greatest  artistic  triumphs  of  the  age 
in  Surgical  Anatomy. — British  American  Medical 
Journal. 

Too  much  cannot  be  said  in  its  praise;  indeed, 
we  have  not  language  to  do  it  justice. — Ohio  Medi- 
cal and  Surgical  Journal. 

The  most  admirable  surgical  atlas  we  have  seen. 
To  the  practitioner  deprived  of  demonstrative  dis- 
sections upon  the  human  subject,  it  is  an  invaluable 
companion. — N.  J.  Medical  .Reporter. 

The  most  accurately  engraved  and  beautifully 
colored  plates  we  have  ever  seen  in  an  American 
book — one  of  the  best  and  cheapest  surgical  works 
ever  published. — Buffalo  Medical  Journal. 

It  is  very  rare  that  so  elegantly  printed,  go  well 
illustrated,  and  so  useful  a  work,  is  offered  at  so 
moderate  a  price. — Charleston  Medical  Journal. 

Its  plates  can  boast  a  superiority  which  places 
them  almost  beyond  the  reach  of  competition. — Medi- 
cal Examiner. 

Every  practitioner,  we  think,  should  have  a  work 
of  this  kind  within  reach. — Southern  Medical  and 
Surgical  Journal. 

No  such  lithographic  illustrations  of  surgical  re- 
gions have  hitherto,  we  think,  been  given. — Boston 
Medical  and  Surgical  Journal. 

As  a  surgical  anatomist,  Mr.  Maclise  has  proba- 
bly no  superior. — British  and  Foreign  Medico-Chi- 
rurgical  Review. 

Of  great  value  to  the  student  engaged  in  dissect- 
ing, and  to  the  surgeon  at  a  distance  from  the  means 


of  keeping  up  his  anatomical  knowledge. — Medical 
Times. 

The  mechanical  execution  cannot  be  excelled. — 
Transylvania  Medical  Journal. 

A  work  which  has  no  parallel  in  point  of  accu- 
racy and  cheapness  in  the  English  language. — N.  Y. 
Journal  of  Medicine. 

To  all  engaged  in  the  study  or  practice  of  their 
profession,  such  a  work  is  almost  indispensable. — 
Dublin  Quarterly  Medical  Journal. 

No  practitioner  whose  means  will  admit  should 
fail  to  possess  it. — Kanking's  Abstract. 

Country  practitioners  will  find  these  plates  of  im- 
mense value. : — iV.  Y.  Medical  Gazette. 

We  are  extremely  gratified  to  announce  to  the 
profession  the  completion  of  this  truly  magnificent 
work,  which,  as  a  whole,  certainly  stands  unri- 
valled, both  for  accuracy  of  drawing,  beauty  of 
coloring,  and  all  the  requisite  explanations  of  the 
subject  in  hand. — The  New  Orleans  Medical  and 
Surgical  Journal. 

This  is  by  far  the  ablest  work  on  Surgical  Ana- 
tomy that  has  come  under  our  observation.  We 
know  of  no  other  work  that  would  justify  a  stu- 
dent, in  any  degree,  for  neglect  of  actual  dissec- 
tion. In  those  sudden  emergencies  that  so  often 
arise,  and  which  require  the  instantaneous  command 
of  minute  anatomical  knowledge,  a  work  of  this  kind 
keeps  the  details  of  the  dissecting-room  perpetually 
fresh  in  the  memory. — The  Western  Journal  of  Medi- 
cine and  Surgery. 

The  very  low  price  at  which  this  work  is  furnished,  and  the  beauty  of  its  execution, 
require  an  extended  sale  to  compensate  the  publishers  for  the  heavy  expenses  incurred. 


MULLER  (PROFESSOR  J.),   M.D. 
PRINCIPLES  OF  PHYSICS   AND  METEOROLOGY.     Edited,  with  Acldi- 

lions,  by  R..  EGLESFF.LD  GRIFFITH,  M.  D.     In  one  large  and  handsome  octavo  volume,  extra 
cloth,  with  550  wood-cuts,  and  two  colored  plates,    pp.  636. 

The  Physics  of  MOller  is  a  work  superb,  complete,  |  tion  to  the  scientific  records  of  this  country  may  be 
unique:  thegreatest  want  known  to  English  Science  |  duly  estimated  by  the  fact  that  the  cost  of  the  origi- 
could  not  have  been  better  supplied.  The  work  is  nal  drawings  and  engravings  alone  has  exceeded  the 
of  surpassing  interest.  The  value  of  this  contribu-  sum  of  £'2,000. — Lancet. 


MAYNE  (JOHN),  M.  D.,  M.  R.  C.  S. 
A  DISPENSATORY  AND  THERAPEUTICAL  REMEMBRANCER.   Com- 

prising  the  entire  lists  of  Materia  Medica,  with  every  Practical  Formula  contained  m  the  three 
Britir-h  Pharmacopoeias.  With  relative  Tables  subjoined,  illustrating,  by  upwards  of  six  hundred 
and  sixty  examples,  the  Extemporaneous  Forms  and  Combinations  suitable  for  the  different 
Medicines.  Edited,  with  the  addition  of  the  Formulae  of  the  United  States  Pharmacoposia,  by 
R.  EGLESFELD  GRIFFITH,  M.  D.  In  one  12mo.  volume,  extra  cloth,  of  over  300  large  pages. 


MATTEUCCI  (CARLO). 
LECTURES  ON  THE  PHYSICAL  PHENOMENA  OF  LIVING  BEINGS. 

Edited  by  J.  PEREIRA,  M.  D.     In  one  neat  royal  12mo.  volume,  extra  cloth,  with  cuts,  388  pages. 


AND    SCIENTIFIC    PUBLICATIONS. 


23 


MILLER  (JAMES),   F.  R.  S.  E., 

Professor  of  Surgery  in  the  University  of  Edinburgh.  &c. 

PRINCIPLES  OF  SURGERY.     Third  American,  from  the  second  and  revised 

Edinburgh  edition.  Revised,  with  Additions,  by  F.  W.  SARGENT,  M.  D-,  author  of  "  Minor  Sur- 
gery," &c.  In  one  large  and  very  beautiful  volume,  of  seven  hundred  and  rifiy-two  pages,  with 
two  hundred  and  forty  exquisite  illustrations  on  wood. 

This  edition  is  far  superior,  both  in  the  abundance  I  gunge.  This  opinion,  deliberately  formed  after  a 
and  quality  of  its  material,  to  any  of  the  preceding.  !  careful  study  of  the  first  edition,  we  have  had  no 
We  hope  it  will  be  extensively  read,  and  the  sound  i  cause  to  chancre  on  examining  the  second.  This 
principles  which  are  herein  Laugh t  treasured  up  for  edition  has  undergone  thorough  revision  by  the  au- 


future  application.  The  work  takes  rank  with 
Watson's  Practice  of  Physic;  it  certainly  does  not 
fall  behind  that  great  work  in  soundness  of  princi- 
ple or  depth  of  reasoning  and  research.  No  physi- 
cian who  values  his  reputation,  or  seeks  the  interests 
ol'his  clients,  can  acquit  himself  before  his  God  and 
the  world  without  making  himself  familiar  with  the 
sound  and  philosophical  views  developed  in  the  fore- 
going book. — Neio  Orleans  Meet,  and  Surg.  Journal. 
Without  doubt  the  ablest  exposition  of  the  prin- 
ciples of  that  branch  of  the  healing  art  in  any  Ian- 


thor;  many  expressions  have  been  modified,  and  a 
mass  of  new  matter  introduced.  The  book  is  got  up 
in  the  finest  style,  and  is  an  evidence  of  the  progress 
of  typography  in  our  country. — Charleston  Medical 
Journal  and  Review. 

We  recommend  it  to  both  student  and  practitioner, 
feeling  assured  that  as  it  now  comes  to  us.  it  pre- 
sents the  most  satisfactory  exposition  of  the  modern 
doctrines  of  the  principles  of  surgery  to  be  found  in 
any  volume  in  any  language. — N.  Y.  Journal  of 
Medicine. 


BY  THE  SAME  AUTHOR.     (Lately  Published.) 

THE  PRACTICE  OF   SURGERY.     Third  American  from  the  second   Eim- 

burgh  edition.     Edited,  with  Additions,  by  F.  W.  SARGENT,  M.  D  ,  one  of  the  Surgeons  to  Will's 

Hospital,  &c.     Illustrated  by  three  hundred  and  nineteen  engravings  on  wood.     In  one  large 

octavo  volume,  of  over  >even  hundred  pages. 

No  encomium  of  ours  could  add  to  the  popularity  |  By  the  almost  unanimous  voice  of  the  profession, 
of  Miller's  Surgery.  Its  reputation  in  this  country  his  works,  both  on  the  principles  and  praclice  of 
is  unsurpassed  by  that  of  any  other  work,  and,  when  surgery  have  been  assigned  the  highest,  rank.  If  we 
taken  in  connection  with  the  author's  Principles  of  were  limited  to  but  one  work  on  surgery,  that  one 
Surgery,  constitu'es  a  whole,  without  reference  to  \  should  be  Miller's,  as  we  regard  it  as  superior  to  all 
which  no  conscientious  surgeon  would  be  willing  j  others. — St.  Louis  Med.  and  Surg.  Journal. 
art  The  additions,  by  Dr.  Sargent, 


to  practice  his 

have  materially  enhanced  the  value  of  the  work. — 

Southern  Medical  and  Surgical  Juurnal. 

It  is  seldom  that  two  volumes  have  ever  made  so 


Theauthor  distinguished  alike  as  a  practitioner 
and  writer,  has  in  this  and  his  "  Principles,"  pre- 
sented to  the  profession  one  of  the  most  completeand 
reliable  systems  of  Surgery  extant.  His  style  of 


profound  an  impression  in  so  short  a  time  as  the  writin?  js  original,  impressive,  and  engaging,  ener- 
<  Principles"  and  the  "Practice"  of  Surgery  by  |  tj  cWise.  and'lucid.  Few  have  the  faculty  of 
Mr.  Miller— or  so  richly  merited  the  reputation  they  ,  condensing  so  much  in  small  space,  and  at  the  same 
have  acquired.  The  author  is  an  eminently  sensi-  time  so  ptrsjsteatly  holding  the  attention;  indeed, 
ble,  practical  and  well-informed  man,  who  knows  j  he  appears  to  make  the  very  process  of  condensation 
exactly  what  he  is  talking  about  and  exactly  how  to  j  a  me.ins  of  eliminating  attractions.  Whether  as  a 
talk  it.— Kentucky  Medical  Recorder.  j  text.book  for  students  or  a  book  of  reference  for 

The  two  volumes  together  forma  complete  expose  j  practitioners,  it  cannot  be  too  strongly  recommend- 
of  the  present  state  of  Surgery,  and  they  ought  to  be  !  ed. — Southern  Journal  of  the  Medical  and  Physical 
on  the  shelves  of  every  surgeon. — N.  J.  Med.  Re-  \  Sciences, 
porter.  I 


MALGAIGNE  (J.   F.). 

.OPERATIVE  SURGERY,  based  on  Normal  and  Pathological  Anatomy.  Trans- 
lated from  the  French,  by  FREDERICK  BRITTAN,  A.  B.,  M.  D.  With  numerous  illustrations  on 
wood.  In  one  handsome  octavo  volume,  of  nearly  six  hundred  pages. 


MOHR  (FRANCIS),  PH.  D.,  AND  REDWOOD  (TH  EOPH  I  LUS). 
PRACTICAL    PHARMACY.     Comprising  the  Arrangements,   Apparatus,  and 

Manipulations  of  the  Pharmaceutical  Shop  and  Laboratory.  Edited,  with  extensive  Additions, 
by  Prof.  WILLIAM  PROCTER,  of  the  Philadelphia  College  of  Pharmacy.  In  one  handsomely 
printed  octavo  volume,  of  570  pages,  with  over  500  engravings  on  wood. 

NEILL   (JOHN),    M.  D., 

Professor  of  Surgery  in  the  Pennsylvania  Medical  College,  &c. 

OUTLINES  OF  THE  ARTERIES.     With   short   Descriptions.     Designed   for 

the  Use  of  Medical  Students.  With  handsome  colored  plates.  Second  and  improved  edition. 
In  one  octavo  volume,  extra  cloth. 

OUTLINES  OF  THE  NERVES.     With  short  Descriptions.     Designed  for  the 

Use  of  Medical  Students.  With  handsome  plates.  Second  and  improved  edition.  In  one  octavo 
volume,  extra  cloth. 

OUTLINES   OF  THE  VEINS   AND   LYMPHATICS.     With  short  Descrip- 

lions.  Designed  for  the  Use  of  Medical  Students.  With  handsome  colored  plates.  In  one  octavo 
volume,  extra  cloth. 

ALSO — The  three  works  done  up  in  one  handsome  volume,  half  bound,  with  numerous  plates,  pre- 
senting a  complete  view  of  the  Circulatory,  Nervous,  and  Lymphatic  Systems. 

This  book  should  be  in  the  hand  of  every  medical 
student.  It  is  cheap,  portable,  and  precisely  the 
thing  needed  in  studying  an  important,  though  diffi- 
cult part  of  Anatomy.  —  Boston  Med.  and  Surg. 
Journal. 


We  recommend  every  student  of  medicine  to  pur- 
chase a  copy  of  this  work,  as  a  labor-saving  ma- 
chine, admirably  adapted  to  refresh  the  memory, 
with  knowledge  gained  by  lectures,  dissections, 


und  the  reading  of  larger  works. — N.  Y.  Journal  of 
Medicine. 

This  work  is  from  the  pen  of  a  Philadelphia  ana- 
tomist, whose  familiar  knowledge  of  the  subject  has 
been  a.ded  by  the  press,  the  result  of  which  is  a  vo- 
lume of  great  beauty  and  excellence.  Its  fine  exe- 
cution commends  it  to  the  student  of  Anatomy.  It 
requires  no  other  recommendations. —  Western  Journ. 
of  Medicine  and  Surgery. 


24  BLANCHARD   &    LEA'S    MEDICAL 

NEILL  (JOHN),   M.  D., 

Surgeon  to  the  Pennsylvania  Hospital, &c.;  and 

FRANCIS  GURNEY   SMITH,   M.D., 

Professor  of  Institutes  of  Medicine  in  the  Pennsylvania  Medical  College. 

AN  ANALYTICAL  COMPENDIUM  OF  THE  VARIOUS  BRANCHES 

OF  MEDICAL  SCIENCE  ;  for  the  Use  and  Examination  of  Student?.  Second  edition,  revised 
and  improved.  In  one  very  large  and  handsomely  printed  royal  12mo.  volume,  of  over  one 
thousand  pages,  with  three  hundred  and  fifty  illustrations  on  wood.  Strongly  bound  in  leather, 
with  raised  bands. 

The  speedy  sale  of  a  large  impression  of  this  work  has  afforded  to  the  authors  gratify  ins  evidence 
of  the  correctness  of  the  views  which  actuated  them  in  its  preparation.  In  meeting  the  demand 
for  a  second  edition,  they  have  therefore  been  desirous  to  render  it  more  worthy  of  the  favor  with 
which  it  has  been  received.  To  accomplish  this,  they  have  spared  neither  time  nor  labor  in  embo- 
dying in  it  Midi  discoveries  and  improvements  as  have  been  made  since  its  first  appearance,  and 
such  alterations  M  have  been  suggested  by  its  practical  use  in  the  class  and  examination-room. 
Considerable  modifications  have  thus  been  introduced  throughout  all  the  departments  treated  of  in 
the  volume,  but  more  especially  in  the  portion  devoted  to  the  "Practice  of  Medicine,"  which  has 
been  entirely  rearranged  and  rewritten. 

Notwithstanding  the  enlarged  size  and  improved  execution  of  this  work,  the  price  has  not  been 
increased,  and  it  is  confidently  presented  as  one  of  the  cheapest  volumes  now  before  the  profession. 


In  the  rapid  course  of  lectures,  where  work  for 
the  students  is  heavy,  and  review  necessary  for  an 
examination,  a  compend  is  not  only  valuable,  but 
it  is  almost  a  sine  qua  non.  The  one  before  us  is, 
in  most  of  the  divisions,  the  most  unexceptionable 
of  all  books  of  the  kind  that  we  know  of.  The 
newest  and  soundest  doctrines  and  the  latest  im- 
provements nnd  discoveries  are  explicitly,  though 
concisely,  laid  before  the  student.  Of  course  it  is 
useless  for  us  to  recommend  it  to  all  last  course 
students,  but  there  is  a  class  to  whom  we  very 
sincerely  commend  this  cheap  book  as  worth  its 
weight  in  silver  —  that  class  is  the  graduates  in 
medicine  of  more  than  ten  years'  standing,  who 
have  not  studied  medicine  since.  They  will  perhaps 
find  out  from  it  that  the  science  is  not  exactly  now 
what  it  was  when  they  left  it  off. — The  Stethoscope 


Having  made  free  use  of  this  volume  in  our  ex- 
aminations of  pupils,  we  can  speak  from  experi- 
ence in  recommending  it  as  an  admirable  compend 
for  students,  and  as  especially  useful  to  preceptors 
who  examine  their  pupils.  It  will  save  the  teacher 
much  labor  by  enabling  him  readily  to  recall  all  of 
the  points  upon  which  his  pupils  should  be  ex- 
amined. A  work  of  this  sort  should  be  in  the  hands 
of  every  one  who  takes  pupils  into  his  office  with  a 
view  of  examining  them ;  and  this  is  unquestionably 
the  best  of  its  class.  Let  every  practitioner  who  has 
pupils  provide  himself  with  it,  and  he  will  find  the 
labor  of  refreshing  his  knowledge  so  much  facilitated 
tliHt  he  will  be  able  to  do  justice  to  his  pupils.'it  very 
little  cost  of  time  or  trouble  to  himself. — Transyl- 
vania Med.  Journal. 


NELIGAN  (J.    MOORE),  M.  D.,  M.  R.  I.  A.,  &c. 
A   PRACTICAL   TREATISE   ON   DISEASES   OF   THE    SKIN.     In  one 

neat  royal  12mo.  volume,  of  334  pages. 

OWEN  (PROF.    R.), 

Author  of  "  Lectures  on  Comparative  Anatomy,"  "  Archetype  of  the  Skeleton,"  &c. 

ON  THE  DIFFERENT  FORMS  OF  THE  SKELETON,  AND  OF  THE 

TEETH.     One  vol.  royal  12mo.,  with  numerous  illustrations.    (Just  Issued.) 
The  name  of  the  distinguished  author  is  a  sufficient  guarantee  that  this  little  volume  will  prove 
a  satisfactory  manual  and  guide  to  all  students  of  Comparative  Anatomy  and  Osteology.     The  im- 
portance of  this  subject  in  geological  investigations  will  also  render  this  work  a    most  valuable 
assistant  to  those  interested  in  that  science. 


PHILLIPS  (BENJAMIN),   F.  R.  S.,  &c. 
SCROFULA ;    its  Nature,  its  Prevalence,  its  Causes,  and  the  Principles  of  its 

Treatment.    In  one  volume,  octavo,  with  a  plale.     pp.  350. 

PANCOAST  (J.),  M.  D., 

Professor  of  Anatomy  in  the  Jefferson  Medical  College,  Philadelphia,  &c. 

OPERATIVE  SURGERY;  or,  A  Description  and  Demonstration  of  the  various 

Processes  of  the  Art ;  including  all  the  New  Operations,  and  exhibiting  the  State  of  Surgical 

Science  in  its  present  advanced  condition.     Complete  in  one  roval  4to.  volume,  of  380  ; 

letter-press  description  and  eighty  large  4to.  plates,  comprising  486  illustrations.     Second  edition, 

improved. 

This  excellent  work  is  constructed  on  the  model  cerned,  we  are  proud  as  an  American  to  say  that, 
of  the  French  Surgical  Works  by  Velpesn  and  Mai-  OF  ITS  KIXD  IT  HAS  NO  SUPERIOR. — JV.  Y.  Journal  of 
gaigne;  and,  so  far  as  the  English  language  is  con-  Medicine. 


PARKER    (LANGSTON), 

Surgeon  to  the  Queen's  Hospital,  Birmingham. 

THE  MODERN  TREATMENT  OF  SYPHILITIC  DISEASES,  BOTH  PRI- 
MARY AND  SECONDARY;  comprising  the  Treatment  of  Constitutional  and  Confirmed  Syphi- 
lis, by  a  safe  and  successful  method.  With  numerous  Cases,  Formulae,  and  Clinical  Observa- 
tions. From  the  Third  and  entirely  rewritten  London  edition.  In  one  neat  octavo  volume, 
of  31>i  pages.  (Just  Issued.) 

Few  of  our  renders  can  require  to  be  informed  and  in  some  parts  has  been  rewritten,  it  is  incum- 
that  Mr.  Lang  (ton  Parker  has  for  some  years  held  bent  on  us  to  describe  a  few  of  its  more  salient  fea- 
one  of  the  h  ghest  positions  as  nn  authority  on  the  tures.  *  *  *  We  can  heartily  recommend  Mr.  Par- 
treatment  of  syphilis.  He  cannot,  therefore,  be  in  ker's  Modern  Treatment  of  Syphilitic  Disenses  ns 
the  position  of  one  who  requires  the  aid  of  the  re-  an  admirable  exposition  of  the  subject  of  which  it 
viewer  to  enable  him  to  bring  to  light  a  first  work  ;  treats.— Association  Medical  Journal. 
but  as  liia  book  has  undergone  an  entire  revision,  ' 


AND   SCIENTIFIC    PUBLICATIONS. 


25 


(Now  Complete.) 

PEREIRA  (JONATHAN),  M.  D.,  F.  R.  S.,  AND  L.  S. 
THE    ELEMENTS    OP    MATERIA    MEDICA    AND    THERAPEUTICS. 

Third  American  edition,  enlarged  and  improved  by  the  author;  including:  Notices  of  most  of  the 
Medicinal  Substances  in  use  in  the  civili/ed  world,  and  forming  an  Encyclopaedia  of  Muleria 
Medica.  Edited,  with  Additions,  by  JOSKPII  CAKSON,  M.  D.,  Professor  of  Maleria  Medica  and 
Pharmacy  in  the  University  of  Pennsylvania.  In  two  very  large  octavo  volumes  of  2100  pages, 
on  small  "type,  with  over  four  hundred  and  fifty  illustrations. 
VOLUME  I. — Lately  issued,  containing  the  Inorganic  Maleria  Medica,  over  800  pages,  with  145 

illustrations. 

VOLUME  II. — Now  ready,  embraces  the  Organic  Materia  Medica,  and  forms  a  very  large  octavo 
volume  of  1250  pages,  with  two  plales  and  three  hundred  handsome  wood-cuts. 
The  present  edition  of  this  valuable  and  standard  work  will  enhance  in  every  respect  its  well- 
deserved  reputation.  The  care  bestowed  upon  its  revision  by  the  author  may  be  estimated  by  t!ie 
fact  that  ils  size  has  been  increased  by  about  five  hundred  pages.  Tliese  additions  have  extended 
to  every  portion  of  the  work,  a'.id  embrace  not  only  the  materials  afforded  by  the  recent  editions  of 
the  pharmacopoeias,  but  also  all  the  important  information  accessible  to  the  care  and  industry  of 
the  author  in  treatises,  essays,  memoirs,  monographs,  and  from  correspondents  in  various  parts  of 
the  globe.  In  this  manner  the  work  comprises  the  most  recent  and  reliable  information  respecting 
all  the  articles  of  the  Materia  Medica,  their  natural  and  commercial  history,  chemical  and  thera- 
peutical properties,  preparation,  uses,  doses,  and  modes  of  administration,  brought  up  to  the  present 
time,  with  a  completeness  not  to  be  met  with  elsewhere.  A  considerable  portion  of  the  work 
which  preceded  the  remainder  in  London,  has  also  enjoyed  the  advantage  of  a  further  revision  by 
the  author  expressly  for  this  country,  and  in  addition  to  this  the  editor,  Professor  Carson,  has  made 
whatever  additions  appeared  desirable  to  adapt  it  thoroughly  to  the  U  S.  Pharmacopeia,  and  to 
the  wants  of  the  American  profession.  An  equal  improvement  will  likewise  be  observable  in  every 
department  of  its  mechanical  execution.  It  is  printed  from  new  type,  on  good  white  paper,  with  a 
greatly  extended  and  improved  series  of  illustrations. 

Gentlemen  who  have  the  first  volume  are  recommended  to  complete  their  copies  without  delay. 
The  first  volume  will  no  longer  be  sold  separate. 

When  we  remember  that  Philology,  Natural  His-  '  Medica,  although  completed  under  the  supervision  of 
tory,  Botany,  Chemistry,  Physics,  and  the  Micro-     ot.hers,  is  by  far   the  most  elaborate  treatise  in  th« 
scope,  are  all  brought  forward  to  elucidate  the  sub-  '  English  language,  and  will,  while  medical  literature 
ject,  one  cannot  fail  to  see  that  r.he  reader  has  here     is  cherished,  continue  a  monument  alike  honorable 
a  work  worthy  of  the  name  of  an  encyclopedia  of!  to   his  genius,  as   to   his   learning  and  industry. — 
Materia  Medica.     Our  own  opinion  of  its  merits  is  i  American  Journal  of  Pharmacy,  March,  1854. 
that  of  its  editors,  and  also  that  of  the  whole  profes-  ! 
sion,   both  of  this  and  foreign   counlrics-namely,        Th<;  W9r.k'  m  its  present  shape,  and  so  far  as  can 


that  in  copiousness  of  details,  in  extent,  variety, 


be  judged  from  the  portion  before  the  public,  forms 


and  accuracy  of  information,  and  in  lucid'explana-  I  tlie   m()st  comprehensive  and  complete  treatise   on 
ti<m  of  difficult  and  recondite  subjects,  it  surpasses     materia  medica  extant  in  the  English  language.— 

Dr.    Pereira   has   been  nt  great  pains  to  introduce 


all  other  works  on   Materia  Medica   hitherto  puh-     f r-   f 

lished."  We  cannot  close  this  nbfice  withbuFallud-    lnto  ''Vs  work,  not  only  all  the  information  on  the 


ferredtobyit.  The  illustrationshave  been  increased,  either  for  preparing  medicines,  or  for  certain  pur- 
and  this  edition  by  Dr.  Carson  cannot  well  be  re-  !  Poses  m  the  arts  connected  with  materia  medica 
garded  in  any  other  light  than  that  of  a  treasure  |  and  the  practice  of  medicine.  The  accounts  of  the 
which  should  be  found  in  the  library  of  every  physi-  j  physiological  and  therapeutic  effects  of  remedies  are 
cian.— New  York  Journal  of  Medical  and  Collateral  !  Slven  wlth  ffreat  clearness  and  accuracy,  and  in  a 


Science,  March,  1851. 


manner,  calculated   to   interest  as  well  as  instruct 


I  the  reader. — The  Edinburgh  Medical  and  Surgical 
The  third  edition  of  his  "Elements  of  Materia  j  Journal. 


PEASELEE  (E.   R.),   M.  D., 

Professor  of  Anatomy  and  Physiology  in  Dartmouth  College,  <fec. 

HUMAN  HISTOLOGY,  in  its  applications  to  Physiology  and  General  Pathology; 

designed  as  a  Text-Book  for  Medical  Students.     With  numerous  illustrations.     In  one  handsome 

royal  12mo.  volume.     (Preparing.) 

The  subject  of  this  work  is  one,  the  growing  importance  of  which,  as  the  basis  of  Anatomy  and 
Physiology,  demands  for  it  a  separate  volume.  The  book  will  therefore  supply  an  acknowledged 
deficiency  in  medical  text-books,  while  the  name  of'the  author,  and  his  experience  as  a  teacher  for 
the  fast  thirteen  years,  is  a  guarantee  that  it  will  be  thoroughly  adapted  to  the  use  of  the  student. 


PIRRIE  (WILLIAM),  F.  R.  S.  E., 

Professor  of  Surgery  in  the  University  of  Aberdeen. 

THE    PRINCIPLES  AND  PRACTICE  OF  SURGERY.    Edited  by  JOHN 

NEILL,  M.  D.,  Professor  of  Surgery  in  the  Penna.  Medical  College,  Surgeon  to  the  Pennsylvania 
Hospital,  &c.     In  one  very  handsome  octavo  volume,  of  780  pages,  with  316  illustrations. 


We  know  of  no  other  surgical  work  of  a  reason- 
able size,  wherein  there  is  so  much  theory  und  prac- 
tice, or  where  subjects  are  more  soundly  or  clearly 
taught. — The  Stethoscope. 

There  ia  scarcely  a  disease  of  the  bone  or  soft 
parts,  fracture,  or  dislocation,  that  is  not  illustrated 
by  accurate  wood-engravings.  Then,  again,  every 
instrument  employed  by  the  surgeon  is  thus  repre- 
sented. These  engravings  are  not  only  correct,  but 


arrived.  Prof.  Pirrie,  in  the  work  before  us,  has 
elaborately  discussed  the  principles  of  surgery,  and 
a  safe  and  effectual  practice  predicated  upon  them. 
Perhaps  no  work  upon  this  subject  heretofore  issued 
is  so  full  upon  the  science  of  the  art  of  surgery. — 
Nashville  Journal  of  Medicine  and  Surgery. 

One  of  the  best  treatises  on  surgery  in  the  English 
language. — Canada  Med.  Journal. 

Our  impression  is,  that,  as  a  manual  for  students, 


really  beautiful,  showing  the  astonishing  degree  of  j  Pirrie's  is  the  best  work  extant. —  Western  Med.  and 
perfection  to  which  the  art  of  wood-engraving  has  |  S«rg-.  Journal. 


2tt  BLANCHARD    &    LEA'S   MEDICAL 

PARRISH    (EDWARD), 
Lecturer  on  Practical  Phnrmacy  and  Materia  Medica  in  the  Pennsylvania  Academy  of  Medicine,  &c. 

A  PRACTICAL  INTRODUCTION   TO  PHARMACY.     Designed  as  a  Text- 

Hook  for  the  Student,  and  as  a  Guide  to  the  Physician  and  Pharmaceutist.  With  numerous 
Formula?  and  Illustrations.  In  one  handsome  octavo  volume.  (Nearly  Ready.) 
The  want  of  an  elementary  text-book  on  this  subject  has  long  been  felt  and  acknowledged 
While  vast  slores  of  information  on  all  the  collateral  branches  of  pharmacy  are  contained  in  such 
works  as  Mohr  and  Redwood,  the  U.  S.  Dispensatory,  the  Pharmacopoeia,  Pereira,  and  others, 
there  has  been  no  compendious  manual  presenting  within  a  moderate  compass,  and  in  systematic 
order,  the  innumerable  minor  details  which  make  up  the  everyday  business  of  those  who  dispense 
medicines.  It  has  been  the  object  of  the  author  to  supply  this  want,  and  while  to  the  pharmaceutist 
Mich  a  work  is  manifestly  indispensable,  its  utility  will  hardly  be  less  to  the  country  practitioner, 
residing  at  a  distance  from  drug  stores,  and  obliged  to  dispense  the  remedies  which  he  prescribes. 
Familiarized  with  the  elements  of  therapeutics  and  the  essentials  of  materia  medica,  by  hi*  at- 
tendance at  lectures,  he  has  hitherto  been  obliged  to  learn  for  himself  the  details  of  prescribing, 
compounding,  and  preparing  medicines.  The  volume  commences  with  a  chapter  on  the"outiit:I 
(A'  the  country  physician,  describing  the  different  articles,  their  various  kinds  and  comparative  ad- 
vantages ;  the  Pharmacopoeia  is  described,  explained,  and  commented  upon,  its  contents  classified 
and  arranged  so  as  to  be  easily  comprehended  and  referred  to;  all  the  operations  of  pharmacy  are 
given  in  minute  detail,  and  under  each  head  the  various  preparations  are  specified  to  which  it  i* 
applicable,  with  directions  for  making  them,  giving  in  this  manner  a  comprehensive  and  practical 
vie  A'  of  the  maleria  medica,  with  much  valuable  information  regarding  all  the  more  important  ar- 
ticles. All  the  officinal  formulae  are  thus  presented,  with  directions  for  their  preparation  and  use, 
together  with  many  empirical  ones  of  interest,  and  numerous  new  ones  derived  from  the  practice 
ol  distinguished  physicians.  Especial  attention  has  been  bestowed  on  the  NEW  REMEDIES,  th« 
more  important  of  which  are  minutely  described,  particularly  those  derived  from  our  indigenous 
plants,  which  have  of  late  attracted  so  much  attention,  and  which  the  author  has  thoroughly 
investigated.  The  chapters  on  extemporaneous  pharmacy  contain  clear  and  accurate  instruction* 
for  writing  prescriptions,  selecting,  combining,  dispensing,  and  compounding  medicines,  making 
powders,  pills,  mixtures,  ointments,  &c.  &c.,  with  formulae;  and  the  work  concludes  with  an  ap- 
pendix of  valuable  hints  and  advice  to  those  purchasing  articles  connected  with  their  profession. 
Numerous  tables  interspersed  throughout  elucidate  the  various  subjects,  which  are  rendered  still 
clearer  by  a  large  number  of  engravings.  Care  has  been  taken  in  all  instances  to  indicate  and 
describe  the  simplest  apparatus  and  procedures  affording  satisfactory  results.  The  long  experience 
of  the  author,  both  as  a  teacher  of  pharmacy,  and  as  a  practical  pharmaceutist,  is  sufficient  guarantee 
of  his  familiarity  with  the  wants  and  necessities  of  the  student,  and  of  his  ability  to  satisfy  them. 


ROKITANSKY  (CARLJ,    M.D., 
Curator  of  the  Imperial  Pathological  Museum,  and  Professor  at  the  University  of  Vienna,  Ac. 

A    MANUAL   OF    PATHOLOGICAL    ANATOMY.     Four  volumes   octavo, 

bound  in  two.     (Now  Ready.) 

Vol.  I. — Manual  of  General  Pathological  Anatomy.     Translated  by  W.  E.  SWAINE. 
Vol.  II. — Pathological  Anatomy  of  the  Abdominal  Viscera.     Translated  by  EDWARD  SIEVEKING, 

M.  D. 
Vol.  III. — Pathological  Anatomy  of  the  Bones,  Cartilages,  Muscles,  and  Skin,  Cellular  and  Fibrous 

Tissue,  Serous  and  Mucous  Membrane,  and  Nervous  System.     Translated  by  C.  H.  MOORE. 
Vol.  IV. — Pathological  Anatomy  of  the  Organs  of  Respiration  and  Circulation.     Translated  by  G. 

E.  DAY. 

To  render  this  large  and  important  work  more  easy  of  reference,  and  at  the  same  time  less  cum- 
brous and  costly,  the  publishers  have  arranged  the  four  volumes  in  two,  retaining,  however,  the 
separate  paging,  &c. 

The  publishers  feel  much  pleasure  in  presenting  to  the  profession  of  the  United  States  the  great 
work  of  Prof.  Rokitansky,  which  is  universally  referred  to  as  the  standard  of  authority  by  the  pa- 
thologists  of  all  nations.  Under  the  auspices  of  the  Sydenham  Society  of  London,  the  combined 
labor  of  four  translators  has  at  length  overcome  the  almost  insuperable  difficulties  which  have  s«. 
long  prevented  the  appearance  of  the  work  in  an  English  dress,  while  the  additions  made  from 
various  papers  and  essays  of  the  author  present  his  views  on  all  the  topics  embraced,  in  the-ir  latest 
published  ibrm.  To  a'  work  so  widely  known,  eulogy  is  unnecessary,  and  the  publishers  would 
merely  state  that  it  contains  the  results  of  not  less  than  THHITY  THOUSAND  post-mortem  examina- 
tions made  by  the  author,  diligently  compared,  generalized,  and  wrought  into  one  complete  antl 
harmonious  system. 

RJGBY  (EDWARD),   M.  D., 
Physician  to  the  General  Lying-in  Hospital,  Sec. 

A   SYSTEM   OF   MIDWIFERY.     With   Notes  and   Additional   Illustrations. 

Second  American  Edition.     One  volume  octavo,  422  pages. 

ROYLE  (J.  FORBES),   M.  D. 
MATERPA  MEDICA  AND  THERAPEUTICS;  including  the  Preparations  of 

the  Pharmacopoeia*  of  London,  Edinburgh,  Dublin,  and  of  the  United  States.  With  many  new 
medicines.  Edited  by  JOSEPH  CARSON,  M.  D.,  Professor  of  Materia  Medica  and  Pharmacy  in 
the  University  of  Pennsylvania.  With  ninety-eight  illustrations.  In  one  large  octavo  volume, 
of  about  seven  hundred  pages. 


This  work  is,  indeed,  a  most  valuable  one,  and 
will  fill  up  an  important  vacancy  that  existed  be- 
tween Dr.  Percira's  most  learned  and  complete 
system  of  Materia  Medica,  anO  the  class  of  pro- 


ductions on  the  other  extreme,  which  are  neces- 
sarily imperfect  from  their  small  extent.— Eritifk 
and  Foreign  Medical  Review. 


AND    SCIENTIFIC    PUBLICATIONS.  27 

RAMSBOTHAM  (FRANCIS  H.),   M.D. 
THE  PRINCIPLES  AND  PRACTICE  OF  OBSTETRIC  MEDICINE  AND 

SURGERY,  in  reference  to  the  Process  of  Parturition.    A  new  and  enlarged  edition,  thoroughly 
revised  by  the  Author.     With  Addition;*  by  W.  V.  KEATING,  JM.  D.     In  one  large  and  handsome 
imperial  octavo  volume,  of  650  pages,  with  sixty-four  beautiful  Plates,  and  numerous;  Wood-cuts 
in  the  text,  containing  in  all  nearly  two  hundred  large  and  beautiful  figures.  (Now  Ready.) 
In  calling  the  attention  of  the  profession  to  the  new  edition  of  this  standard  work,  the  publishers 
would  remark  that  no  efforts  have  been  spared  to  secure  for  it  a  continuance  and  extension  of  the 
remarkable  favor  with  which  it  has  been  received.     The  last  London  issue,  which  was  considera- 
bly enlarged,  has  received  a  further  revision  from  the  author,  especially  for  this  country.     Its  pas- 
sage through  the  press  here  has   been  supervised  by  Dr.  Keating,  who  has  made  numerous  addi- 
tions with  a  view  of  presenting  more  fully  whatever  was   necessary  to  adapt  it  thoroughly  to 
American  modes  of  practice.     In  its  mechanical  execution,  n  like  superiority  over  former  editions 
will  be  found.     The  plates  have  all  been  re-engraved  in  a  new  and  beautiful  style  ;  many  additional 
illustrations  have  been  introduced,  and  in  every  point  of  typographical  finish  it  will  be  found  one  of 
the  handsomest  issues  of  the  American  press.     In  its  present  improved  and  enlarged  form  the  pub- 
lishers therefore  confidently  ask  for  it  a  place  in  every  medical  library,  as  a  text-book  for  the  student, 
or  a  manual  for  daily  reference  by  the  practitioner. 

From  Prof.  Hodge,  of  the  University  of  Pa. 

To  the  American  public,  it  is  most  valuable,  from  its  intrinsic  undoubted  excellence,  and  &B  being 
the  best  authorized  exponent  of  British  Midwifery.  Its  circulation  will,  1  trust,  be  extensive  throughout 
our  country. 

The  publishers  have  shown  their  appreciation  of  cine  and  Surgery  to  our  library,  and  confidently 
the  merits  of  this  work  and  secured  its  success  by  recommend  it  to  our  readers,  with  the  assurance 
the  truly  elegant  style  in  which  they  have  brought  that  it  will  not  disappoint  their  most  sanguiiie  ex- 
it out,  excelling  themselves  in  its  production,  espe-  pectations. —  Western  Lancet. 

cially  in  its  plates.  It  is  dedicated  to  Prof.  Meigs,  !t  is  unnecessary  to  sav  anything  in  regard  to  the 
and  has  the  emphatic  endorsement  of  Prof.  Hodge,  utjiity  of  this  work  It  -„  Kiready  appreciated  in  our 
as  the  best  exponent  01  British  Midwifery.  \\  e  country  for  the  value  of  the  matter,  the  clearness  of 
know  of  no  text-book  which  deserves  in  all  respects  its  styie  .,nd  the  fulness  ()f  its  illustrations.  To  the 
to  be  more  highly  recommenced  to  students,  and  we  physician's  library  it  is  indispensable,  while  to  the 
could  wish  to  see  it  m  thehandsof  every  practitioner,  stu(jeiit  as  a  text-book,  from  which  to  extract  the 
for  they  will  find  it  invaluable  for  relerence.— Med.  n,!lterial  for  laying  the  foundation  of  an  educiition  on 
irazette.  •  obstetrical  science,  it  has  no  superior. — Ohio  lied. 

But  once  in  a  long  time  some  brilliant  genius  rears    and  Surg.  Journal. 
his  head  above  the  horizon  of  science,  and  illumi-  ' 

nates  and  purifies  every  department  that  he  investi-  .  ^  e  will  only  arid  that  the  student  will  learn  from 
gates ;  and  his  works  become  types,  by  which  innu-  I1  a"  be  need  to  know,  and  the  practitioner  will  find 
inerable  imitators  model  their  feeble  productions.  lt-  as  a  b"ok  of  reference,  surpassed  by  none  other.— 
Such  a  genius  we  find  in  the  younger  Ramsbotliam,  .  Stethoscope. 

and  such  a  type  we  find  in  the  work  now  before  us.  The  character  and  merits  of  Dr.  Ramsbotham's 
The  binding,  paper,  type,  the  engravings  anil  wood-  work  are  so  well  known  and  thoroughly  established, 
cuts  are  all  so  excellent  as  to  make  this  book  one  of  that  comment  is  unnecessary  and  praise  superfluous. 
the  finest  specimens  of  the  art  of  printing  that  have  The  illustrations,  which  are  numerous  and  accurate, 
given  such  a  world-wide  reputation  to  its  enterpri-  !  are  executed  in  the  highest  style  of  art.  We  cannot 
sing  and  liberal  publishers.  We  welcome  Rams-  i  too  highly  recommend  the  work  to  our  readers. — St. 
botham's  Principles  and  Practice  of  Obstetric  Medi-  '  Louis  Med  and  Surg.  Journal. 

RICORD  (P.),   M.  D., 
Surgeon  to  the  Hopital  du  Midi.  Paris,  &c. 

ILLUSTRATIONS  OF  SYPHILITIC  DISEASE.   Translated  from  the  French, 

by  THOMAS  F.  BETTO.N,  M.  D.  With  the  addition  of  a  History  of  Syphilis,  and  a  complete  Bib- 
liography and  Formulary  of  Remedies,  collated  and  arranged,  by  PAUL  B.  GODDARD,  M.D.  With 
fifty  large  quarto  plates,  comprising  one  hundred  and  seventeen  beautifully  colored  illustrations. 
Ill  one  large  aud  handsome  quarto  volume. 

BY  THE  SAME  AUTHOR.     (Lately  Published.) 

A  TREATISE  ON  THE  VENEREAL  DISEASE.     By  JOHN  HUNTER,  F.  R.  S. 

With  copious  Additions,  by  PH.  RICORD,  M.  D.  Edited,  with  Notes,  by  FREEMAN  J.  BUMSTEAD, 
M.  D.  In  one  handsome  octavo  volume,  of  520  pages,  with  plates. 

Every  one  will  recognize  the  attractiveness  and!  In  the  notes  to  Hunter,  the  master  substitutes  him- 
value  which  this  work  derives  from  ihus  presen'ing  j  self  for  his  interpreters,  and  gives  his  original  thoughts 
the  opinions  of  these  two  masters  side  by  side.  But.  to  the  world,  in  a  summary  form  it  is  true,  but  in  a 
it  must  be  admiited.  what  has  made  the  fonune  of  lucid  and  perfectly  inte.llisible  manner.  lii  conclu- 
the  book,  is  the  fact  that  ii  contains  the  "most  com-  j  sion  we  can  say  that  this  is  incomestably  the  best 
p'ete  embodiment  of  the  veritable  doctrines  of  the  treatise  on  syphilis  with  which  we  are  acquainted, 
Hopital  du  Midi."  which  has  ever  been  made  public.  ;  and.  as  we  do  not  often  employ  the  phrase,  we  may 
The  doctrinal  kiras  of  M.  Ricord.  ;dea?  which,  if  not  be  excused  for  expressing  the  hope  that  it  may  find 
universally  adopted,  are  ineoiilesiably  dominant,  have  a  place  in  ihe  library  of  every  physician  —  Virginia 
heretofore  only  been  interpreted  by  more  or  less  (skilful  Med.  and  Surg  Journal. 
secretaries,  somei.mi-s  accredited  and  sometimes  not.  j 

BY   THE   SAME    AUTHOR. 

LETTERS  ON  SYPHILIS,  addressed  to  the  Chief  Editor  of  the  Union  .Modicale. 

With  an  Introduction,  by  Aniedee  Latour.  Translated  by  \V.  P.  Lattimore,  M.  D.  In  one  neat 
octavo  volume  of  270  pages. 

BY   THE   SAME   AUTHOR. 

A  PRACTICAL  TREATISE  ON  VENEREAL  DISEASES.     With  a  Thera- 

peutical  Summary  and  Special  Formulary.  Translated  by  SIDNEY  DOANE,  M.  D.  Fourth  edition. 
One  volume,  octavo,  .340  pages. 


28 


BLANCHARD    &   LEA'S    MEDICAL 


SMITH    (HENRY    H.),   M.  D., 

Professor  of  Surgery  in  the  University  of  Pennsylvania.  &c. 

MINOR  SURGERY;  or,  Hints  on  the  Every-day  Duties  of  the  Surgeon.  Illus- 
trated by  two  hundred  and  forty-seven  illustrations.  Third  and  enlarged  edition.  In  one  hand- 
some royal  12mo.  volume,  pp.  456. 


And  a  capital  little  book  it  is.  .  .  Minor  Surgery, 
we  repeat,  is  really  Major  Surgery,  anil  anything 
which  teaches  it  is  worth  having.  So  we  cordially 
recommend  this  little  bonk  of  Dr.  Smith's.— Med.- 
CMr.  Review. 

This  beautiful  little  work  has  been  compiled  with 
a  view  to  the  wants  of  the  profession  in  the  matter 
of  bandaging,  &c.,und  well  and  ably  has  the  author 
performed  his  labors.  Well  adapted  to  give  the 
requisite  information  on  the  subjects  of  which  it 
treats. — Medical  Examiner. 

The  directions  are  plain,  and  illustrated  through- 
out with  clear  engravings. —  London  Lnncet. 

One  of  the  best  works  they  can  consult  on  the 
subject  of  which  it  treats. — Southern  Journal  of 
Medicine  and  Pharmacy. 


A  work  such  as  the  present  is  therefore  highly 
useful  to  tUe  student,  and  we  commend  this  one 
to  their  attention. — American  Journal  of  Medical 
Sciences. 

No  operator,  however  eminent,  need  hesitate  to 
consult  this  unpretending  yet  excellent  book.  Those 
who  are  young  in  the  business  would  find  Dr.  Smittvs 
treatise  a  necessary  companion,  after  once  under- 
standing its  true  character. — Boston  Med.  and  Surg. 
Journal, . 

No  young  practitioner  should  be  without  this  little 
volume;  and  we  venture  to  assert,  that  it  may  be 
consulted  by  the  senior  members  of  the  profession 
with  more  real  benefit,  than  the  more  volum  nous 
works. —  Western  Lancet. 


BY   THE   SAME    AUTHOR,    AND 

HORNER  (WILLIAM  E.),   M.D., 
L:ite  Professor  of  Anatomy  in  the  University  of  Pennsylvania. 

AN  ANATOMICAL  ATLAS,  illustrative  of  the  Structure  of  the  Human  Body. 

In  one  volume,  large  imperial  octavo,  with  about  six  hundred  and  fifty  beautiful  figures. 


These  figures  are  well  selected,  and  present  a 
complete  and  accurate  representation  of  that  won- 
derful fabric,  the  human  body.  The  plan  of  this 
Atlas,  which  renders  it  so  peculiarly  convenient 
for  the  student,  and  its  superb  artistical  execution, 
have  been  already  pointed  out.  We  must  congratu- 


late the  student  upon  the  completion  of  this  Atlas, 
as  it  is  the  most  convenient  work  of  the  kind  tnat 
has  yet  appeared  ;  and  we  must  add,  the  very  beau- 
tiful manner  in  which  it  is  "  got  up"  is  so  creditable 
to  the  country  as  to  be  flattering  to  our  national 
pride. — American  Medical  Journal. 


SARGENT  (F.  W.),   M.  D. 
ON  BANDAGING  AND  OTHER  POINTS   OF  MINOR  SURGERY.     In 

one  handsome  royal  12mo.  volume  of  nearly  400  pages,  with  128  wood-cuts. 

The  very  best  manual  of  Minor  Surgery  we  have  j  We  have  carefully  examined  this  work,  and  find  it 
seen  ;  an  American  volume,  with  nearly  four  hundred  well  executed  and  admirably  adapted  to  the  use  of 
pages  of  good  practical  lessons,  illustrated  by  about  the  student.  Besides  the  subjects  usually  embraced 
one  hundred  and  thirty  wood-cuts.  In  these  days  in  works  on  Minor  Surgery,  there  is  a  short  chapter 
of  "trial,"  -when  a  doctor's  reputation  hangs  upon  '  on  bathing,  another  on  anaesthetic  agents,  and  an 
a  clove  hitch,  or  the  roll  of  a  bandage,  it  would  be  appendix  of  formulae.  The  author  has  given  an  ex- 
well,  perhaps,  to  carry  such  a  volume  as  Mr.  Sar-  cellentwork  on  this  subject, and  his  publishers  have 
gent's  always  in  our  coat-pocket,  or,  at  all  events,  illustrated  and  printed  it  in  most  beautiful  style. — 
to  listen  attentively  to  his  instructions  at  home. —  The  Charleston  Medical  Journal. 
Buffalo  Med.  Journal. 


SKEY  (FREDERICK  C.),   F.  R.  S.,  &c. 
OPERATIVE  SURGERY.     In  one  very  handsome  octavo  volume  of  over  650 

pages,  with  about  one  hundred  wood-cuts. 


SHARPEY  (WILLIAM),    M.D.,    JONES   QUAIN,    M.D.,   AND 
RICHARD   QUAIN,    F.  R.  S.,  &c. 

HUMAN  ANATOMY.     Revised,  with  Notes  and  Additions,  by  JOSEPH  LEIDY, 

M.  D.     Complete  in  two  large  octavo  volumes,  of  about  thirteen  hundred  pages.     Beautifully 
illustrated  with  over  five  hundred  engravings  on  wood. 


It  is  indeed  a  work  calculated  to  make  an  era  in 
,  anatomical  study,  by  placing  before  the  student 
every  department  of  his  science,  with  a  view  to 
the  relative  importance  of  each  ;  and  so  skilfully 
have  the  different  parts  been  interwoven,  that  no 
one  who  makes  this  work  the  basis  of  his  studies, 
will  hereafter  have  any  excuse  for  neglecting  or 
undervaluing  any  important  particulars  connected 
with  the  structure  of  the  human  frame;  and 
whether  the  bias  of  his  mind  lead  him  in  a  more 
especial  manner  to  surgery,  physic,  or  physiology, 
he  will  find  here  a  work  at  once  so  comprehensive 
and  practical  as  to  defend  him  from  exclusiveness 
--•'  --J  nedantry  on  the  other.— 


on  the  one  hand,  and  pedc 
Monthly  Journal  and  Retr 
Sciences. 


We  have  no  hesitation  in  recommending  this  trea- 
tise on  anatomy  as  the  most  complete  on  that  sub- 
ject in  the  English  language;  and  the  only  one, 
perhaps,  in  any  language,  which  brings  the  state 
of  knowledge  forward  to  the  most  recent  disco- 
veries.— The  Edinburgh  Med.  and  Surg.  Journal. 

Admirably  calculated  to  fulfil  the  object  for  which 
it  is  intended. — Provincial  Medical  Journal. 

The  most  complete  Treatise  on  Anatomy  in  the 
English  language. — Edinburgh  Medical  Journal. 

There  is  no  work  in  the  English  language  tn  lie 
preferred  to  Dr.  Quain's  Element*  of  Anatomy. — 


•aspect  of  the   Medical  j  London  Journal  of  Medicine 


STANLEY  (EDWARD). 
A  TREATISE  ON  DISEASES  OF  THE   BONES.     In  one  volume,  octavo, 

extra  cloth,  286  pages. 

SOLLY  (SAMUEL),   F.  R.  S. 
THE    HUMAN    BRAIN;    its  Structure,  Physiology,  and  Diseases.     With  a 

Description  of  the  Typical  Forms  of  the  Brain  in  the  Animal  Kingdom.     From  the  Second  and 
much  enlarged  London  edition.     In  one  octavo  volume  of  500  pages,  with  120  wood-cuts. 


AND    SCIENTIFIC    PUBLICATIONS.  29 

STILLE  (ALFRED),   M.  D. 
PRINCIPLES    OF    GENERAL    AND    SPECIAL    THERAPEUTICS.     In 

handsome  octavo.     (Preparing.) 

SIMON    (JOHN),  F.  R.  S. 
GENERAL    PATHOLOGY,    as   conducive  to  the   Establishment  of  Rational 

Principles  for  the  Prevention  and  Cure  of  Disease.  A  Course  of  Lectures  delivered  at  St. 
Thomas's  Hospital  during  the  summer  Session  of  1830.  In  one  uc-at  octavo  volume,  of  212 
pages. 

SMITH  (W.   TYLER),  M.  D., 

Physician  Accoucheur  to  St.  Mary's  Hospital,  &c. 

ON   PARTURITION,    AND   THE   PRINCIPLES    AND   PRACTICE   OF 

OBSTETRICS.     In  one  large  duodecimo  volume,  of  400  pages. 

BY  THE  SAME  AUTHOR. — (Now  Ready.) 

A  PRACTICAL  TREATISE  ON  THE  PATHOLOGY  AND  TREATMENT 

OF  LEUCORRIICEA.     With  numerous  illustrations.     In  one  very  handsome  octavo  volume  of 

aixmt  250  pajres. 

The  investigation  of  the  pathology  and  treatment  j  work  will  he  sufficient  to  prove  its  value,  and  we 


of  leucorrhcBrt  is  n  task  that  may  well  engage  the 
time  and  energies  of  the  most  philosophical  and 
skilled  physician  ;  and  there  are  few  men  more  capa- 
ble of  conducting  and  deducing  important  observa- 
tions from  sucli  a  study  than  the  author  of  the  pre- 
sent treatise,  l/r.  Tvler  Smith's  previous  researches. 


hope  more  than  enough  to  induce  every  practitioner 
to  study  it  for  himself. — The  Lancet. 

The  above  list  contains  simply  the  general  head- 
ings of  the  different  chapters;  to  have  enumerated 
all  the  subjects  discussed,  or  to  have  made  further 
extracts,  would  have  compelled  us  much  to  exceed 


no  t  less  than  ins  aevotmn  to  physiology  and  scientific  I  our  ijmjts.  This,  however,  we  scarcely  regret: 
medi  cine,  point  him.,  lit  as  one  eminently calculated  |  becrln8e  we  think  a  perusal  of  the  extracts  given 
to  throw  light  on  many  subjects,  which  less  able  wlll  im(uce  tne  reader  to  examine  the  worfc  for  hira- 
men  might  tail  to  elucidate.  \Ve  consequently  take  i  gelf .  ami  we  woui<j  advise  all  who  are  anxious  for 
his  work  in  hand  with  high  expectations  and  we  '  corr'oct  ideas  respecting  these  discharges,  and  their 
nave  not  been  in  the  least  disappointed.  The  fore-  !  sources,  to  possess  themselves  of  it.— Dublin  JVTtrf. 
going  cursory  examination  of  Dr.  Tyler  Smith's  ;  press_ 


SIBSON    (FRANCIS),    M.  D., 

Physician  to  St.  Mary's  Hospital. 

MEDICAL  ANATOMY.     Illustrating  the  Form,  Structure,  and  Position  of  the 

Internal  Organ.*  in  Health  and  Disease.     In  large  imperial  quarto,  with  splendid  colored  plates. 
To  match  "Maclise's  Surgical  Anatomy."    Part  I.     (Nearly  Ready.) 


SCHOEDLER  (FRIEDRICH),   PH.D., 

Professor  of  the  Natural  Sciences  at  Worms,  &c. 

THE   BOOK   OF   NATURE;    an  Elementary  Introduction  to  the  Sciences  of 

Physics,  Astronomy,  Chemistry,  Mineralogy,  Geology,  Botany,  Zoology,  and  Physiology.  First 
American  edition,  with  a  Glossary  and  other  Additions  and  Improvements;  from  the  second 
English  edition.  Translated  from  the  sixth  German  edition,  by  HENRY  MKDLOCK,  F.  C.  S.,  <kc. 
In  one  thick  volume,  small  octavo,  of  about  seven  hundred  pages,  with  679  illustrations  on  wood. 
Suitable  for  the  higher  Schools  and  private  students.  (Now  Ready.) 


TOMES  (JOHN),    F.  R.  S. 
A  MANUAL  OF  DENTAL  PRACTICE.     Illustrated  by  numerous  engravings 

on  wood.     In  one  handsome  volume.     (Preparing.) 


TRANSACTIONS  OF   THE   AMERICAN    MEDICAL   ASSOCIATION. 
VOLUME  VIII,  for  1855,  8vo.,  extra  cloth.     (Nearly  Ready.') 

A  few  complete  sets  can  still  be  had,  in  eight  volumes,  price  ?"S.     Applications  and  remittances 

to  be  made  to  CASPAR  WISTER,  M.  D.,  Treasurer,  Philadelphia. 
*#*  These  volumes  are  published  by  and  sold  for  account  of  the  Association. 


TODD  (R.  B.),   M.  D.,  AND  BOWMAN  (WILLIAM),   F.  R.  S. 
PHYSIOLOGICAL    ANATOMY  AND    PHYSIOLOGY   OF  MAN.     With 

numerous  handsome  wood-cuts.    Parts  I,  II,  and  III,  in  one  octavo  volume,  552  pages.     Part  IV 

will  complete  the  work. 

The  first  portion  of  Part  IV,  wilh  numerous  original  illustrations,  was  published  in  the  Medical 
News  and  Library  for  1853,  and  the  completion  will  be  issued  immediately  on  its  appearance  in 
London.  Those  who  have  subscribed  since  the  appearance  of  the  preceding-  portion  of  the  work 
can  have  the  three  parts  by  mail,  on  remittance  of  $2  50  to  the  publishers. 


TOYNBEE  (JOSEPH),   F.  R.  S., 

Aural  Surgeon  to  St.  Mary's  Hospital,  &c. 

A  MANUAL  OF  AURAL  SURGERY;  being  a  complete  Treatise  on  Diseases 

of  the  Ear.     Illustrated  with  numerous  engravings  on  wood,  from  original  drawings.     In  on« 
octavo  volume.     (Preparing.) 


30  kBLANCHARD    &    LEA'S    MEDICAL 

TANNER    (T.    HJ,    M.  D., 

Physic-inn  to  the  Hospital  for  Women,  &c. 

A  MANUAL  OF  CLINICAL  MEDICINE  AND  PHYSICAL  DIAGNOSIS. 

To  which  is  added  The  Code  of  Ethics  of  the  American  Medical  Association.     In  one  neat 

volume,  small  12mo.,  extra  cloth.  (Now  Ready.) 

The  object  of  this  little  work  is  to  furnish  the  practitioner,  in  a  condensed  and  convenient  com- 
pa-:s.  and  at  a  trilling  cost,  with  u  guide  for  the  daily  exigencies  of  his  practice.  A  large  portion  of 
the  volume  is  occupied  with  details  of  diagnostic  symptoms,  classified  under  the  different  seats  of 
disease  This,  in  itself,  is  well  worth  the  price  of  the  book,  but  in  addition,  there  will  be  (bund  an 
immense  amount  of  information,  not  usually  touched  upon  in  the  systematic  worlcs,  or  scattered 
throughout  many  different  volumes — such  as  general  rules  for  conduct,  taking  notes,  clinical  exami- 
nation of  children  and  of  the  insane,  post-mortem  examinations,  medico-legal  examinations, exami- 
nation* for  life  insurance,  instruments  employed  in  diagnosis,  such  as  (he  microscope,  tests,  the 
spirometer,  dynamometer,  stelhometer.  stethoscope,  pleximeter,  ophthalmoscope,  speculum,  uterine 
sound,  I.\TC.  ;  directions  for  the  chemical  and  microscopical  examination  of  the  blood,  urine,  sputa, 
&c.  \rc.  ;  with  many  other  subjects  of  equal  importance  which  hitherto  the  young  practitioner  has 
had  to  learn  in  a  great  measure  from  experience  alone.  Although  necessarily  treated  in  a  condensed 
manner,  the  topics  will  be  found  to  embrace  the  lalest  and  most  approved  modes  of  procedure,  while 
the  addition  of  the  admirable  "Code  of  Ethics"  of  the  American  Medical  Association  renders  it 
complete  as  a  guide  for  the  student  and  as  a  manual  of  daily  reference  for  the  younger  practitioner. 

Those  who  desire  to  use  it  as  a  vade-mecum  for  the  pocket,  can  obtain  copies  neatly  done  up  in 
flexible  cloth. 


TAYLOR  (ALFRED  S.),  M.  D.,  F.  R.  S., 

Lecturer  on  Medical  Jurisprudence  and  Chemistry  in  Guy's  Hospital. 

MEDICAL  JURISPRUDENCE.     Third  American,  from  the  fourth  and  improved 

English  Edition.    With  Notes  and  References  to  American  Decisions,  by  EDWARD  HARTSHORNE, 
M.  D.     In  one  large  octavo  volume,  of  about  seven  hundred  pages.     (Just  Issued.) 

We  know  of  no  work  on  Medical  Jurisprudence  none  could  be  offered  to  the  busy  practitioner  of 
which  contains  in  the  same  space  anything  like  the  i  either  calling,  for  the  purpose  of  casual  or  hasty 
same  amount  of  valuable  mutter  — A1.  Y.  Journal  of  reference,  that  would  be  more  likely  toatford  the  aid 
Medicine.  \  desired.  We  therefore  recommend  it  as  the  best  and 

No  work  upon  the  subject  can  he  put  into  the    Sil('est  mnnunl  for  daily  use.— American  Journal  of 
hands  of  students  either  of  law  c.r  medicine  which    MeAical  Sciences. 
will  engage  them  more  closely  or  profitably;  and  , 

BY   THE   SAME    AUTHOR. 

ON  POISONS,  IN  RELATION  TO   MEDICAL  JURISPRUDENCE   AND 

MEDICINE.    Edited,  with  Notes  and  Additions,  by  R.  E.  GRIFFITH,  M.  D.    In  one  large  octavo 
volume,  of  688  pages. 


The  most  elaborate  work  on  the  subject  that  our 
literature  possesses. — British  and  Foreign  Medico- 
Ctiirurgical  Review. 


One  of  the  most  practical  and  trustworthy  works 
on  Poisons  in  our  language. — Western  Journal  of 
Medicine. 


THOMSON  (A.  T.),  M.  D.,  F.  R.  S.,  &c. 
DOMESTIC  MANAGEMENT   OF   THE   SICK   ROOM,  necessary  in  aid  of 

Medical  Treatment  for  the  Cure  of  Diseases.    Edited  by  R.  E.  GRIFFITH,  M.  D.     In  one  large 
royal  l'2rao.  volume,  with  wood-cuts,  360  pages 

WATSON    (THOMAS),    M.  D.,    &c. 

LECTURES    ON    THE   PRINCIPLES    AND    PRACTICE    OF   PHYSIC. 

Third  American,  from  the  last  London  edition.    Revised,  with  Additions,  by  D.  FKAMCIS  CONDIE, 

M.D.,  author  of  a  "Treatise  on  the  Diseases  of  Children,"  &e.     In  one  octavo  volume,  of  nearly 

eleven  hundred  large  pages,  strongly  bound  with  raised  bands. 

To  say  that  it  is  the  very  best  work  on  the  sub-         Confessedly  one  of  the  very  best  works  on  the 
ject  now  extant,  is  but  to  echo  the  sentiment  of  the    principles  and  practice  of  physic  in  the  English  or 
medical    press    throughout    the    country.  —  JV.    O.  ;  any  other  language. — Med.  Examiner. 
Medical  Journal.  Ag  n  text.book  it  hag  no  equal .  ag  .,  compendium 


Of  the  text-books  recently  republished  Watson  is 
very  justly  the  principal  favorite. — Holmes's  Rep. 
to  Nat.  Med.  Assoc. 

By  universal  consent  the  work  ranks  among  the 
very  best  text-books  in  our  language. — Illinois  and 
Indiana  Med.  Journal. 

Regarded  on  all  hands  as  one  of  the  very  best,  if 
not  the  very  best,  systematic  treatise  on  practical 


medicine  extant. — Si.  Louis  Med.  Journal.  \  Journal. 


of  pathology  and  practice  no  superior. — New  York 
Annalist. 

We  know  of  no  work  better  calculated  for  being 
placed  in  the  hands  of  the  student,  and  for  a  text- 
book; on  every  important  point  the  author  seems 
to  have  posted  up  his  knowledge  to  the  day. — 
Anier.  Med.  Journal. 

One  of  the  most  practically  useful  books  that 
ever  was  presented  to  the  student.  —  A'.  Y.  Med. 


WHAT   TO   OBSERVE 
AT    THE    BEDSIDE    AND    AFTER   DEATH,    IN    MEDICAL   CASES. 

-hed  under  the  authority  of  the  London  Society  for  Medical  Observation.    A  new  American, 

from  the  second  and  revised  London  edition.     In  one  very  handsome  volume,  royal  12mo.,  extra 

cloth.     (Now  Ready.) 

The  demand  which  has  so  rapidly  exhausted  the  first  edition  of  this  little  work,  shows  that  the 
advantages  it  offers  to  the  profession  have  been  duly  appreciated,  and  has  stimulated  the  authors  to 
render  it  more  worthy  of  its  reputation.  It  has  therefore  been  thoroughly  revised,  and  such  im- 
provements (among  which  is  a  section  on  TREATMENT)  have  been  made  as  further  experience  in 
its  use  has  shown  to  be  desirable. 

To  the  observer  who  prefers  accuracy  to  blunders  I      One  of  the  finest  aids  to  a  young  practitioner  we 
and  precision  to  carelessness,  this  little  book  is  in-     have  ever  seen. — Peninsular  Journal  of  Medicine. 
valuable. — N.  If.  Journal  of  Medicine. 


AND    SCIENTIFIC    PUBLICATIONS.  31 

WILSON    (ERASMUS),   M.D.,    F.  R.  S., 

Lecturer  on  Anatomy,  London. 

'A  SYSTEM  OF  HUMAN  ANATOMY,  General  and  Special.     Fourth  Ameri- 

can,  from  the  last  English  edition.     Edited  by  PAUL  B.  GODDARIJ,  A.  M.,  M  D.     With  two  hun- 
dred and  fitly  illustrations.     Beautifully  printed,  in  one  large  octavo  volume,  of  nearly  six  hun- 
dred pages. 
In  many,  if  not  all  the  Colleges  of  the  Union,  it  ,      It  offers  to  the  student  all  the  assistance  that  can 

lias  become  u  standard  text-book.     This,  of  itself,  |  be  expected  from  auch  a  work. — Medical  Examiner. 

<s  sufficiently  expressive  of  its  value.     A  work  very  :      The  mogt  colnp|ete  an<J  convenient  manual  for  the 

desirable   to   the   student;    one,  the    possession   of    stlujent  we  possess— American  Journal  of  Medical 

which    will   greatly    facilitate   his   progress  in  the     Science 

study  of  Practical  Anutomy. — A'ttc  Tori  Journal  of 

Medicine  •  every   respect,   this  work   as   an   anatomical 

guide  for  the  student  and   practitioner,  merits   our 
Its  author  ranks  with  the  highest  on  Anatomy. —    warmest  and  most  decided  praise. — London  Medical 

Soutkf.rn  Medical  and  Surgical  Journal.  i  Gazette. 

BY   THE   SAME   AUTHOR. 

THE    DISSECTOR;    or,  Practical  and  Surgical  Anatomy.     Modified   and  Re- 
arranged, by  PAUL  BECK  GODDARD,  M.  D.    A  new  edition,  with  Revision*  and  Additions.     In 
one  large  and  handsome  volume,  royal  12mo.,  of  458  pages,  with  115  illustrations. 
In  passing  this  work  again  through  the  press,  the  editor  has  made  such  additions  and  improve- 
ments as  the  advance  of  anatomical  knowledge  has  rendered  necessary  to  maintain  the  work  in  ih« 
high  reputation  which  it  ha.*  acquired  in  the  schools  of  the  United  Slates,  as  a  complete  and  faithful 
guide  to  the  student  of  practical  anatomy.     A  number  of  new  illustrations  have  been  added,  espe- 
cially in  the  portion  relating  to  the  complicated  anatomy  of  Hernia.     In  mechanical  execution  the 
work  will  be  found  superior  to  former  editions. 

BY    THE    SAME    AUTHOR. 

ON    DISEASES    OF   THE    SKIN.     Third  American,  from  the  third  London 

edition.     In  one  neat  octavo  volume,  of  about  five  hundred  pages,  extra  cloih.     (Just  Issued.) 
Also,  to  be  had  done  up  with  fifteen  beautiful  steel  plates,  of  which  eight  are  exquisitely  colored; 

representing  the  Normal  and  Pathological  Anatomy  ofthe  Skin,  together  with  accurately  colored 

delineations  of  more  than  sixty  varieties  of  disease,  most  of  them  the  size  of  nature.     The  Plates 

are  also  for  sale  separate,  done  up  in  boards. 

The  "Diseases  of  the  Skin,"   by  Mr.  Erasmus  I  nothing  to  he  desired,  so  far  as  excellence  of  delinea- 
WiUon,  may  now  be  regarded  as  the  standard  work  |  tion   and  perfect  "accuracy  of  illustration  are  con- 
m    that  department  of    medical    literature.      The  I  cerned. — Mzdico-Chirurgical  Review. 
plales  by  which  tins  edition  is  accompanied  leave  | 

BY   THE   SAME   AUTHOR. 

ON    CONSTITUTIONAL    AND    HEREDITARY    SYPHILIS,   AND    ON 

SYPHILITIC  ERUPTIONS.     la  one  small  octavo  volume,  beautifully  printed,  with  four  exqui- 
site colored  plates,  presenting  more  than  thirty  varieties  of  syphilitic  eruptions. 

BY   THE   SAME   AUTHOR.      (Now  Ready.) 

HEALTHY  SKIN;  A  Popular  Treatise  on  the  Skin  and  Hair,  their  Preserva- 
tion and  Management.  Second  American,  from  the  fourth  London  edition.  One  neat  volume, 
royal  lUmo.,  of  about  300  pages,  with  numerous  illustrations. 

Copies  can  be  had  done  up  in  paper  covers  for  mailing,  price  75  cents. 


WHITEHEAD  (JAMES),    F.  R.  C.  S.,    &c. 
THE  CAUSES  AND  TREATMENT  OF  ABORTION  AND  STERILITY; 

being  the  Result  of  an  Extended  Practical  Inquiry  into  the  Physiological  and  Morbid  Conditions 
of  the  Uterus.     Second  American  Edition.     In  one  volume,  octavo,  368  pages.     (Now  Ready.) 


f*uch  are  the  advances  made  from  year  to  year  in 
this  department  of  our  profession,  that  the  practi- 
tioner who  does  not  consult  the  recent  works  on  the 
complaints  of  females,  will  soon  find  himself  in  the 
rear  of  his  more  studious  brethren.  This  is  one  of 


the  works  which  must  be  studied  by  those  who 
would  know  what  the  present  state  of  our  knowledge 
is  respecting  the  causes  and  treatment  of  abortion 
and  sterility. — The  Western  Journal  of  Medicine  and 
Surgery. 


WALSHE'lW.    H.),    M.  D., 

Professor  ofthe  Principles  and  Practice  of  Medicine  in  University  College,  London. 

DISEASES    OF    THE    HEART,    LUNGS,    AND    APPENDAGES;    their 

Symptoms  and  Treatment.     In  one  handsome  volume,  large  royal  12mo.,  512  page?. 

We  consider  this  as  the  ablest  work  in  the  En-  1  the  author  being  the  first  stethoscopist  ofthe  day. — 
glish  language,  on  tbe  subject  of  which  it  treats;  |  Charleston  Medical  Journal. 

WILDE   (W.    R.), 

Surgeon  to  St.  Mark's  Ophthalmic  and  Aural  Hospital.  Dublin. 

AURAL  SURGERY,  AND  THE  NATURE  AND  TREATMENT  OF  DIS- 
EASES OF  THE  EAR.     In  one  handsome  octavo  volume  of  470  pages,  with  illustrations. 
This  work  certainly  contain?  more  information  on  ]  laws,  and  amenable  to  the  same  general  methods  of 
ihe  subject  to  which  it  is  devoted   lhan   any  oilier  t  treatment  as  other  morbid  processes.    The  work  i« 
with  which  we  are  acquainted.     We  feel  grateful  ro  1  not  written  to  supply  the  cravings  of  popular  patro- 


iiie  author  for  his  inanful  effort  to  rescue  tins  depart 
menl  of  surgery  from  the  band*  of  the  empirics  who 
nearly  monopolize  it.  We  think  he  ha?  successfully 


shown  that  aural  disease*  are  not  beyond   the  re    I  Med.  Journal. 
es  of  art:  that  they  are  governed  by  the  same 


n»ge,  Inn  it  is  wholly  addressed  to  the  profession, 
and  bears  on  every  pngetht-  impress  of  tne  reflection? 
of  a  sagiiciou*  and  practical  surgeou. —  Va..  Sitrg.  and 


32  BLANCHARD   &    LEA'S    SCIE  N  T  IF  1C  PUBL  1C  AT  I ONS. 


WEST   (CHARLES),    M.  D., 

*hysician  to  the  Hospital  for  Sick  Children,  &c. 

YTTI       T\Tr-m   i   rn^fi       ^~\TI      TXTT^   t   XT/I~\T       A 


Phy 

LECTURES    ON   THE   DISEASES   OF  INFANCY  AND   CHILDHOOD. 

Second  American,  from  the  Second  and  Enlarged  London  edition.     In  one  volume,  octavo,  of 
nearly  five  hundred  pages.    (Just  Issued.) 


We  take  leave  of  Dr.  West  with  great  respect  for 
his  attainments,  a  due  appreciation  of  his  acute 
powers  of  observation,  and  a  deep  sense  of  obiiga- 


upon  a  subject  which  almost  daily  taxes  to  the  ut- 
most the  skill  of  the  general  practitioner.  lie  has 
with  singular  felicity  threaded  his  way  through  till 


tion  for  this  valuable  contribution   to  our  profes-     the  tortuous  labyrinths  of  the  difficult  subject  he  has 
iional  literature.     His  book  is  undoubtedly  in  many    undertaken  to  elucidate,  and  has   in    many   of  the 


respects  the  best  we  possess  on  diseasesof  children. 
The  extracts  we  have  given  will,  we  hope,  satisfy 
our  readers  of  its  value;  and  yet  in  all  candor  we 
must  gay  that  they  are  even  inferior  to  some  other 
parts,  the  length  of  which  prohibited  our  entering 
upon  them.  That  the  book  will  shortly  be  in  the 
hands  of  most  of  our  readers  we  do  not  doubt,  and  it 
will  give  us  much  pleasure  if  our  strong  recommend- 
ation of  it  may  contribute  towards  the  result. — The 
Dublin  Quarterly  Journal  of  Medical  Science. 

Dr.  West  has  placed  the  profession  under  deep  ob- 


darkest  corners  left  a  light,  for  the  benefit  of  suc- 
ceeding travellers,  which  will  never  be  extinguished. 
Not  the  least  captivating  feature  in  this  admirable 
performance  is  its  easy,  conversational  style,  which 
acquires  force  from  its  very  simplicity,  and  leaves 
an  impression  upon  the  memory,  of  the  truths  it 
conveys,  as  clear  and  refreshing  as  its  own  purity. 
The  author's  position  secured  him  extraordinary  fa- 
cilities for  the  investigation  of  children's  diseases, 
and  his  powers  of  observation  and  discrimination 
have  enabled  him  to  make  the  most  of  these  great 
advantages. — Nashville  Medical  Journal. 


ligation  by  this  able,  thorough,  and  finished  work 

BY  THE  SAME  AUTHOR.      (Just  Issued) 

AN  ENQUIRY  INTO  THE  PATHOLOGICAL  IMPORTANCE  OF  ULCER- 

ATION  OF  THE  OS  UTERI.     Being  the  Croonian  Lectures  for  the  year  1854.    In  one  neat 
octavo  volume,  extra  cloth. 


WILLIAMS  (C.   J.   B.(,    M.  D.,    F.  R.  S., 

Professor  of  Clinical  Medicine  in  University  College,  London,  &c. 

PRINCIPLES   OF  MEDICINE;   comprising  General  Pathology  and  Therapeu- 

ties,  and  a  brief  general  view  of  Etiology,  Nosology,  Semeiology,  Diagnosis,  Prognosis,  and 
Hygienics.  Edited,  with  Additions,  by  MEREDITH  OLYMER,  M.  D.  Fourth  American,  from  the 
last  and  enlarged  London  edition.  In  one  octavo  volume,  of  476  pages.  (Lately  Issued.) 

It  possesses  the  strongest  claims  to  the  attention  of  the  medical  student  and  practitioner,  from 
the  admirable  manner  in  which  the  various  inquiries  in  the  different  branches  of  pathology  are 
investigated,  combined,  and  generalized  by  an  experienced  practical  physician,  and  directly  applied 
to  the  investigation  and  treatment  of  disease. — EDITOR'S  PREFACE. 

The  best  exposition  in  our  language,  or,  we  be-  I  Few  books  have  proved  more  useful,  or  met  with 
lieve,  in  any  language,  of  rational  medicine,  in  its  |  a  more  ready  sale  than  this,  and  no  practitioner 
present  improved  and  rapidly  improving  state. —  I  should  regard  his  library  as  complete  without  it. 
British  and  Foreign  Medico-Chirurg.  Review.  \  — Ohio  Med.  and  Surg.  Journal. 

BY    THE   SAME   AUTHOR. 

A  PRACTICAL  TREATISE  ON  DISEASES  OF  THE  RESPIRATORY 

ORGANS;  including  Diseases  of  the  Larynx,  Trachea,  Lungs,  and  Pleiirre.  With  numerous 
Additions  and  Notes,  by  M.  CLYMER,  M.  D.  With  wood-cuts.  In  one  octavo  volume,  pp.  508. 


YOUATT  (WILLIAM),  V.  S. 
THE    HORSE.     A  new  edition,  with  numerous  illustrations;   together  with  a 

general  history  of  the  Horse;  a  Dissertation  on  the  American  Trotting  Horse;  how  Trained  and 
Jockeyed ;  an  Account  of  his  Remarkable  Performances ;  and  an  Essay  on  the  Ass  and  the  Mule. 
By  J.  S.  SKINNER,  formerly  Assistant  Postmaster-General,  and  Editor  of  the  Turf  Register. 
One  large  octavo  volume. 

BY   THE   SAMEVuTHOR. 

THE   DOG.     Edited  by  E.  J.  LEWIS,   M.  D.     With   numerous   and  beautiful 

illustrations.     In  one  very  handsome  volume,  crown  Svo.,  crimson  cloth,  gilt. 

ILLUSTRATED  MEDICAL  CATALOGUE, 

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